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Jiang S, Matuszewska M, Chen M, Hong Y, Chen Y, Wang Z, Zhuang H, Sun L, Zhu F, Wang H, Wu X, Ji S, Holmes MA, Ba X, Chen Y, Yu Y. Emergence and spread of ST5 methicillin-resistant Staphylococcus aureus with accessory gene regulator dysfunction: genomic insights and antibiotic resistance. Microbiol Res 2025; 297:128196. [PMID: 40311457 DOI: 10.1016/j.micres.2025.128196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2025] [Revised: 04/23/2025] [Accepted: 04/24/2025] [Indexed: 05/03/2025]
Abstract
The globally disseminated Staphylococcus aureus ST5 clone poses a major public health threat due to its multidrug resistance and virulence. Here, we identified an agr-dysfunctional (agrA-I238K) ST5 MRSA clone that has spread across East and Southeast Asia, with recent increases in China since its emergence in the 1970s. Comparative genomic analyses identified distinct single-nucleotide polymorphisms and mobile genetic elements linked to enhanced resistance and virulence. This clone exhibits resistance to seven antimicrobial classes, including third-generation tetracyclines and fusidic acid, and shares phenotypic and genetic similarities with the vancomycin-intermediate S. aureus Mu50 strain, including reduced susceptibility to vancomycin, teicoplanin, and daptomycin. The agrA-I238K mutation attenuates hemolytic activity, increases biofilm formation, and reduces daptomycin susceptibility, suggesting a key role in the clone's success. Our results demonstrate the important role of agrA-I238K mutation in the widespread distribution of agr-dysfunctional MRSA and highlight the importance of genomic surveillance in tracking the spread of agr-dysfunctional ST5 MRSA.
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Affiliation(s)
- Shengnan Jiang
- Centre of Laboratory Medicine, Department of Clinical Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China; Zhejiang University School of Medicine, Hangzhou, Hangzhou, Zhejiang, China; Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Marta Matuszewska
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK; Department of Medicine, University of Cambridge, Cambridge, UK; Wellcome Sanger Institute, University of Cambridge, Cambridge, UK
| | - Mengzhen Chen
- Hangzhou Center for Disease Control and Prevention, Hangzhou, China
| | - Yueqin Hong
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yiyi Chen
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhengan Wang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Hemu Zhuang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Lu Sun
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Feiteng Zhu
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Haiping Wang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xueqing Wu
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shujuan Ji
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mark A Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Xiaoliang Ba
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
| | - Yan Chen
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Yunsong Yu
- Centre of Laboratory Medicine, Department of Clinical Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China; Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
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Girma A. Staphylococcus aureus: Current perspectives on molecular pathogenesis and virulence. Cell Surf 2025; 13:100137. [PMID: 39758277 PMCID: PMC11699754 DOI: 10.1016/j.tcsw.2024.100137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2024] [Revised: 12/04/2024] [Accepted: 12/07/2024] [Indexed: 01/07/2025] Open
Abstract
Staphylococcus aureus has evolved a sophisticated regulatory system to control its virulence. One of the main roles of this interconnected network is to sense and respond to diverse environmental signals by altering the synthesis of virulence components required for survival in the host, including cell surface adhesins, extracellular enzymes and toxins. The accessory gene regulator (agr), a quorum sensing system that detects the local concentration of a cyclic peptide signaling molecule, is one of the well-studied of these S. aureus regulatory mechanisms. By using this system, S. aureus is able to sense its own population density and translate this information into a specific pattern of gene expression. In addition to Agr, this pathogen senses specific stimuli through various two-component systems and synchronizes responses with alternative sigma factors and cytoplasmic regulators of the SarA protein family. These different regulatory mechanisms combine host and environmental information into a network that guarantees the best possible response of pathogens to changing circumstances. In this article, an overview of the most significant and thoroughly studied regulatory systems of S. aureus is provided, along with a summary of their roles in host interactions.
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Affiliation(s)
- Abayeneh Girma
- Department of Biology, College of Natural and Computational Science, Mekdela Amba University, P.O. Box 32, Tulu Awuliya, Ethiopia
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Chen T, Ye Z, Huang W, Zhang Q, Jiang F, Yang Z, Jian Y, Wang Y, Xiang G, Liu Q, Shen H, Li M, He L. Fe-S cluster deficiency drives small colony variant formation in persistent infections. J Adv Res 2025:S2090-1232(25)00310-8. [PMID: 40381909 DOI: 10.1016/j.jare.2025.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2025] [Revised: 04/22/2025] [Accepted: 05/08/2025] [Indexed: 05/20/2025] Open
Abstract
INTRODUCTION Small colony variants (SCVs) of Staphylococcus aureus (S. aureus) are associated with persistent infections and poor clinical outcomes. The mechanisms driving stable SCV formation remain poorly understood, particularly concerning metabolic adaptations. This study explores the in-host evolutionary dynamics of S. aureus and identifies a novel genetic determinant linked to SCV formation. OBJECTIVES To investigate the genetic mutations and phenotypic adaptations underlying SCV formation, with a focus on the role of a novel mutation in the sufB gene, which is critical for Fe-S cluster biosynthesis. METHODS Sequential isolates from a patient with recurrent infections were analyzed using whole-genome sequencing, antimicrobial susceptibility testing, and functional assays. The phylogenetic relationship of the isolates was determined, and specific mutations were identified. Functional assays included aconitase and glutamate synthase activity measurements, ATP level quantification, reactive oxygen species (ROS) production, and biofilm formation assays. In vivo pathogenesis was assessed using a murine catheter infection model. RESULTS A novel frameshift mutation in sufB was identified, disrupting Fe-S cluster biosynthesis and impairing the TCA cycle and electron transport chain, leading to reduced ATP and ROS production. This metabolic reprogramming promoted stable SCV formation, characterized by slow growth, enhanced tolerance to antibiotics and neutrophil-mediated killing, and persistent inflammation in vivo. Restoration of sufB reversed these phenotypes, confirming its pivotal role in SCV-associated persistence. CONCLUSION sufB is a novel genetic determinant of stable SCV formation through Fe-S cluster deficiency, driving metabolic shifts that enhance immune evasion and chronic infection. Our findings highlight antibiotic stewardship and suggest potential therapeutic strategies for managing persistent SCV-associated infections.
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Affiliation(s)
- Tianchi Chen
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Zhiyi Ye
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Weiyi Huang
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Qi Zhang
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Feng Jiang
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200235, China
| | - Ziyu Yang
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Ying Jian
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Yanan Wang
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Guoxiu Xiang
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Qian Liu
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Hao Shen
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200235, China
| | - Min Li
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; School of Nursing, Shanghai Jiao Tong University, Shanghai 200025, China; College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Lei He
- Department of Laboratory Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China; College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
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Bergersen KV, Zheng Y, Rossetti M, Ruffin F, Pickering H, Parmar R, Sunga G, Chan LC, Gjertson D, Fowler VG, Yeaman MR, Reed EF. Early cytokine signatures and clinical phenotypes discriminate persistent from resolving MRSA bacteremia. BMC Infect Dis 2025; 25:231. [PMID: 39966757 PMCID: PMC11834594 DOI: 10.1186/s12879-025-10620-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2024] [Accepted: 02/07/2025] [Indexed: 02/20/2025] Open
Abstract
BACKGROUND Staphylococcus aureus bacteremia (SAB) is a prevalent life-threatening infection often caused by methicillin-resistant S. aureus (MRSA). Up to 30% of SAB patients fail to clear infection even with gold-standard anti-MRSA antibiotics. This phenomenon is termed antibiotic-persistent MRSA bacteremia (APMB). The mechanisms driving APMB are complex and involve host phenotypes significantly impacting the immune response. Thus, defining early immune signatures and clinical phenotypes that differentiate APMB from antibiotic resolving (AR)MB could aid therapeutic success. METHODS We assessed 38 circulating cytokines and chemokines using affinity proteomics in 74 matched pairs of vancomycin-treated SAB cases identified as ARMB or APMB after 5 days of blood culture. RESULTS Unsupervised hierarchical clustering segregated APMB from ARMB based on differential levels of IL-10, IL-12p40, IL-13, CCL4, and TGFα. Additionally, CXCL1, CCL22 and IL-17A significantly differed between APMB and ARMB when correlated with diabetes, dialysis, metastatic infection, or cardiac vegetation. Combining immune signatures with these relevant clinical phenotypes sharply increased accuracy of discriminating APMB outcome to 79.1% via logistic regression modeling. Finally, classification-regression tree analysis revealed explicit analyte thresholds associated with APMB outcome at presentation especially in patients with metastatic infection. CONCLUSIONS Collectively, this study identifies previously unrecognized cytokine and chemokine signatures that distinguish APMB and ARMB at presentation and in the context of host clinical characteristics associated with increased disease severity. Validation of a biomarker signature that accurately predicts outcomes could guide early therapeutic strategies and interventions to reduce risks of persistent SAB that are associated with worsened morbidity and mortality.
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Affiliation(s)
- Kristina V Bergersen
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, 1000 Veteran Ave, Los Angeles, CA, 90095, USA
| | - Ying Zheng
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Maura Rossetti
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Felicia Ruffin
- Division of Infectious Diseases, Duke University School of Medicine, 2301 Erwin Road, Durham, NC, 27710, USA
| | - Harry Pickering
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, 1000 Veteran Ave, Los Angeles, CA, 90095, USA
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Rajesh Parmar
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, 1000 Veteran Ave, Los Angeles, CA, 90095, USA
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Gemalene Sunga
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, 1000 Veteran Ave, Los Angeles, CA, 90095, USA
| | - Liana C Chan
- Institute for Infection and Immunity, Lundquist Institute at Harbor UCLA Medical Center, Torrance, CA, USA
- Division of Molecular Medicine, Los Angeles County Harbor-UCLA Medical Center, Torrance, CA, USA
| | - David Gjertson
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Vance G Fowler
- Division of Infectious Diseases, Duke University School of Medicine, 2301 Erwin Road, Durham, NC, 27710, USA.
- Duke Clinical Research Institute, Duke University, Durham, NC, USA.
| | - Michael R Yeaman
- Institute for Infection and Immunity, Lundquist Institute at Harbor UCLA Medical Center, Torrance, CA, USA.
- Division of Molecular Medicine, Los Angeles County Harbor-UCLA Medical Center, Torrance, CA, USA.
- Division of Infectious Diseases, Los Angeles County Harbor-UCLA Medical Center, Torrance, CA, USA.
- Divisions of Molecular Medicine and Infectious Diseases, David Geffen School of Medicine and Harbor-UCLA Medical Center, 1124 West Carson Street, Building MRL / 250, Torrance, CA, 90502, USA.
| | - Elaine F Reed
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, 1000 Veteran Ave, Los Angeles, CA, 90095, USA.
- UCLA Immunogenetics Center, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
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Li Y, Berti AD, Abdelhady W, Xiong YQ. Prophage ϕSA169 Enhances Vancomycin Persistence in Methicillin-Resistant Staphylococcus aureus (MRSA). Antibiotics (Basel) 2025; 14:191. [PMID: 40001434 PMCID: PMC11852059 DOI: 10.3390/antibiotics14020191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2024] [Revised: 01/25/2025] [Accepted: 02/11/2025] [Indexed: 02/27/2025] Open
Abstract
Background: Persistent methicillin-resistant Staphylococcus aureus (MRSA) endovascular infections present a significant clinical therapeutic challenge. Prophages are increasingly recognized as important genetic factors influencing the pathogenicity of S. aureus, yet their role in antibiotic persistence in MRSA remains underexplored. Our previous work demonstrated that prophage ϕSA169 promotes vancomycin (VAN) persistence in an experimental model of endocarditis caused by MRSA strains with a clonal complex (CC) 45 genetic background. However, it is unknown whether this persistence-promoting effect of ϕSA169 extends to other clinically relevant MRSA lineages. This study aims to elucidate the role of ϕSA169 in influencing VAN persistence across diverse MRSA genetic backgrounds. Methods: A pilot analysis of clinical data suggested that patients infected by MRSA containing ϕSA169-like prophage appear to have worse clinical outcomes. Thus, we lysogenized representative clinical resolving bacteremia (RB) MRSA strains with ϕSA169 and evaluated phenotypes closely associated with VAN persistence, including VAN susceptibility, biofilm formation, and the efficacy of VAN treatment in an experimental infective endocarditis (IE) model. Each ϕSA169 lysogenic strain was compared to its isogenic MRSA parental counterpart. Results: ϕSA169 lysogeny significantly promotes biofilm formation and enhances survival to VAN exposure under human-mimicking conditions for RB strains from CC5 and CC30. ϕSA169 lysogeny significantly reduces VAN effectiveness in the IE model due to RB lysogen from CC5 despite no detectable impact on VAN MICs. Conclusions: These results indicate that ϕSA169 promotes VAN persistence across clonal backgrounds, likely through biofilm formation and VAN tolerance. Targeting prophage could provide new strategies to combat persistent MRSA infections.
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Affiliation(s)
- Yi Li
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA; (Y.L.); (W.A.)
| | - Andrew D. Berti
- Department of Pharmacy Practice, Wayne State University College of Pharmacy and Health Sciences, Detroit, MI 48201, USA;
| | - Wessam Abdelhady
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA; (Y.L.); (W.A.)
| | - Yan Q. Xiong
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA; (Y.L.); (W.A.)
- David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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Al Shaikhli H, Akins RL, Stover KR, Barber KE. Exploring combination treatment options for persistent methicillin-susceptible Staphylococcus aureus bacteremia. Am J Health Syst Pharm 2025; 82:150-163. [PMID: 39230345 DOI: 10.1093/ajhp/zxae252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Indexed: 09/05/2024] Open
Abstract
PURPOSE This review explores the management of persistent methicillin-susceptible Staphylococcus aureus bacteremia (SAB), emphasizing the importance of timely intervention due to SAB's association with metastatic dissemination, relapse, and mortality. SUMMARY The literature analysis first delves into risk factors for persistent SAB, highlighting the need for effective treatment strategies. The subsequent focus is on combination strategies for persistent SAB. Daptomycin, ertapenem, ceftaroline, fosfomycin, rifampin, and gentamicin are explored as adjuncts to cefazolin or antistaphylococcal penicillins. Daptomycin combination therapy is assessed through in vivo and clinical studies, indicating potential benefits, especially with higher-risk sources of infection. Ertapenem combination therapy has been demonstrated to have a synergistic effect with cefazolin, presenting a viable salvage option. Rifampin's ability to penetrate biofilm is examined, with discussion of inconclusive evidence on mortality benefits. The review also considers stewardship implications, discussing concerns such as resistance emergence, adverse events, and increased costs associated with combination therapy. Mathematical models suggest combination therapy as an effective approach to prevent resistance. Adverse events vary with each combination, and duration of therapy remains diverse across studies in the absence of well-established dosing guidelines. CONCLUSION The review provides a thorough exploration of the literature on treatment of persistent SAB, underscoring the need for evidence-based guidelines, further studies, and clinical judgment in tailoring treatment strategies. The multifaceted analysis contributes valuable insights for clinicians managing this challenging condition.
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Yang E, Cho YG, Kim E, Chang E, Bae S, Jung J, Kim MJ, Chong YP, Kim SH, Choi SH, Lee SO, Chung YS, Kim YS. Clinical and microbiological characteristics of persistent Staphylococcus aureus bacteremia, risk factors for mortality, and the role of CD4 + T cells. Sci Rep 2024; 14:15472. [PMID: 38969796 PMCID: PMC11226624 DOI: 10.1038/s41598-024-66520-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 07/02/2024] [Indexed: 07/07/2024] Open
Abstract
This study evaluated the determinants of mortality and the T cell immune response in patients with persistent Staphylococcus aureus bacteremia (SAB). This was a prospective cohort study and patients with confirmed SAB were enrolled from 2008 to 2020. We compared clinical, microbiological, and genotypic features between surviving and deceased patients with persistent SAB. The concentrations of cytokines and the proportions of IFN-γ secreting CD4+ T cells were measured serially during the bacteremia period. Of the 1760 patients, 242 had persistent bacteremia (PB), and 49 PB patients died within 30 days. In the multivariate analysis, the APACHE II score and female sex were independently associated with 30 days mortality. The level of IL-10 was significantly increased in the plasma of patients with a high Pitt bacteremia score and those who died within 12 weeks from the index day. The proportion of IFN-γ-secreting CD4+ T cells were the highest just before the positive-to-negative conversion of blood cultures in patients with a low Pitt bacteremia score and those who survived for 12 weeks. The level of IL-10 is correlated with clinical outcomes in PB patients. IFN-γ secreting CD4+ T cells might play a pivotal role in SAB PB.
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Affiliation(s)
- Eunmi Yang
- Division of Infectious Diseases, Seoul Medical Center, Seoul, South Korea
| | - Yeong Geon Cho
- Center for Antimicrobial Resistance and Microbial Genetics, University of Ulsan College of Medicine, Seoul, South Korea
- Asan Institute for Life Science, Asan Medical Center, Seoul, South Korea
| | - Eunsil Kim
- Center for Antimicrobial Resistance and Microbial Genetics, University of Ulsan College of Medicine, Seoul, South Korea
- Asan Institute for Life Science, Asan Medical Center, Seoul, South Korea
| | - Euijin Chang
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Seongman Bae
- Center for Antimicrobial Resistance and Microbial Genetics, University of Ulsan College of Medicine, Seoul, South Korea
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Jiwon Jung
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Min Jae Kim
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Yong Pil Chong
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Sung-Han Kim
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Sang-Ho Choi
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Sang-Oh Lee
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Yun Shin Chung
- Center for Antimicrobial Resistance and Microbial Genetics, University of Ulsan College of Medicine, Seoul, South Korea
| | - Yang Soo Kim
- Center for Antimicrobial Resistance and Microbial Genetics, University of Ulsan College of Medicine, Seoul, South Korea.
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro43-gil, Songpa-gu, Seoul, 05505, South Korea.
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Piewngam P, Otto M. Staphylococcus aureus colonisation and strategies for decolonisation. THE LANCET. MICROBE 2024; 5:e606-e618. [PMID: 38518792 PMCID: PMC11162333 DOI: 10.1016/s2666-5247(24)00040-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 03/24/2024]
Abstract
Staphylococcus aureus is a leading cause of death by infectious diseases worldwide. Treatment of S aureus infections is difficult due to widespread antibiotic resistance, necessitating alternative approaches and measures for prevention of infection. Because S aureus infections commonly arise from asymptomatic colonisation, decolonisation is considered a key approach for their prevention. Current decolonisation procedures include antibiotic-based and antiseptic-based eradication of S aureus from the nose and skin. However, despite the widespread implementation and partial success of such measures, S aureus infection rates remain worrisome, and resistance to decolonisation agents is on the rise. In this Review we outline the epidemiology and mechanisms of S aureus colonisation, describe how colonisation underlies infection, and discuss current and novel approaches for S aureus decolonisation, with a focus on the latest findings on probiotic strategies and the intestinal S aureus colonisation site.
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Affiliation(s)
- Pipat Piewngam
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, MD, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, MD, USA.
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Chin JL, Tan ZC, Chan LC, Ruffin F, Parmar R, Ahn R, Taylor SD, Bayer AS, Hoffmann A, Fowler VG, Reed EF, Yeaman MR, Meyer AS. Tensor modeling of MRSA bacteremia cytokine and transcriptional patterns reveals coordinated, outcome-associated immunological programs. PNAS NEXUS 2024; 3:pgae185. [PMID: 38779114 PMCID: PMC11109816 DOI: 10.1093/pnasnexus/pgae185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 04/17/2024] [Indexed: 05/25/2024]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a common and life-threatening infection that imposes up to 30% mortality even when appropriate therapy is used. Despite in vitro efficacy determined by minimum inhibitory concentration breakpoints, antibiotics often fail to resolve these infections in vivo, resulting in persistent MRSA bacteremia. Recently, several genetic, epigenetic, and proteomic correlates of persistent outcomes have been identified. However, the extent to which single variables or their composite patterns operate as independent predictors of outcome or reflect shared underlying mechanisms of persistence is unknown. To explore this question, we employed a tensor-based integration of host transcriptional and cytokine datasets across a well-characterized cohort of patients with persistent or resolving MRSA bacteremia outcomes. This method yielded high correlative accuracy with outcomes and immunologic signatures united by transcriptomic and cytokine datasets. Results reveal that patients with persistent MRSA bacteremia (PB) exhibit signals of granulocyte dysfunction, suppressed antigen presentation, and deviated lymphocyte polarization. In contrast, patients with resolving bacteremia (RB) heterogeneously exhibit correlates of robust antigen-presenting cell trafficking and enhanced neutrophil maturation corresponding to appropriate T lymphocyte polarization and B lymphocyte response. These results suggest that transcriptional and cytokine correlates of PB vs. RB outcomes are complex and may not be disclosed by conventional modeling. In this respect, a tensor-based integration approach may help to reveal consensus molecular and cellular mechanisms and their biological interpretation.
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Affiliation(s)
- Jackson L Chin
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Zhixin Cyrillus Tan
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Liana C Chan
- The Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Division of Infectious Diseases, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | - Felicia Ruffin
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC 27710, USA
| | - Rajesh Parmar
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Richard Ahn
- Institute for Quantitative and Computational Biosciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Scott D Taylor
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Arnold S Bayer
- The Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Alexander Hoffmann
- Institute for Quantitative and Computational Biosciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Vance G Fowler
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC 27710, USA
| | - Elaine F Reed
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael R Yeaman
- The Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Division of Infectious Diseases, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC 27710, USA
| | - Aaron S Meyer
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90024, USA
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90024, USA
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90024, USA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90024, USA
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10
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Liu X, Wang Y, Chang W, Dai Y, Ma X. AgrA directly binds to the promoter of vraSR and downregulates its expression in Staphylococcus aureus. Antimicrob Agents Chemother 2024; 68:e0089323. [PMID: 38259090 PMCID: PMC10916378 DOI: 10.1128/aac.00893-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 12/15/2023] [Indexed: 01/24/2024] Open
Abstract
Staphylococcus aureus is an important human pathogen and vancomycin is widely used for the treatment of S. aureus infections. The global regulator agr is known as a well-described virulence regulator. Previous studies have found that agr-dysfunction strains are more likely to develop into vancomycin-resistant strains, but the mechanism for this phenomenon remains unknown. VraSR is a two-component regulatory system related to vancomycin resistance. In this study, we found that the expression levels of vraR were higher in agr-dysfunction clinical strains than in the agr-functional strains. We knocked out agr in a clinical strain, and quantitative reverse transcription PCR and β-galactosidase activity assays revealed that agr repressed transcription of vraR. After vancomycin exposures, population analysis revealed larger subpopulations displaying reduced susceptibility in agr knockout strain compared with wild-type strain, and this pattern was also observed in agr-dysfunction clinical strains compared with the agr-functional strains. Electrophoretic mobility experiment demonstrated binding of purified AgrA to the promoter region of vraR. In conclusion, our results indicated that the loss of agr function in S. aureus may contribute to the evolution of reduced vancomycin susceptibility through the downregulation of vraSR.
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Affiliation(s)
- Xueer Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yangyan Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
| | - Wenjiao Chang
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yuanyuan Dai
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Xiaoling Ma
- Department of Clinical Laboratory, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
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11
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Yamazaki Y, Ito T, Tamai M, Nakagawa S, Nakamura Y. The role of Staphylococcus aureus quorum sensing in cutaneous and systemic infections. Inflamm Regen 2024; 44:9. [PMID: 38429810 PMCID: PMC10905890 DOI: 10.1186/s41232-024-00323-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/15/2024] [Indexed: 03/03/2024] Open
Abstract
BACKGROUND Staphylococcus aureus is a leading cause of human bacterial infections worldwide. It is the most common causative agent of skin and soft tissue infections, and can also cause various other infections, including pneumonia, osteomyelitis, as well as life-threatening infections, such as sepsis and infective endocarditis. The pathogen can also asymptomatically colonize human skin, nasal cavity, and the intestine. S. aureus colonizes approximately 20-30% of human nostrils, being an opportunistic pathogen for subsequent infection. Its strong ability to silently spread via human contact makes it difficult to eradicate S. aureus. A major concern with S. aureus is its capacity to develop antibiotic resistance and adapt to diverse environmental conditions. The variability in the accessory gene regulator (Agr) region of the genome contributes to a spectrum of phenotypes within the bacterial population, enhancing the likelihood of survival in different environments. Agr functions as a central quorum sensing (QS) system in S. aureus, allowing bacteria to adjust gene expression in response to population density. Depending on Agr expression, S. aureus secretes various toxins, contributing to virulence in infectious diseases. Paradoxically, expressing Agr may be disadvantageous in certain situations, such as in hospitals, causing S. aureus to generate Agr mutants responsible for infections in healthcare settings. MAIN BODY This review aims to demonstrate the molecular mechanisms governing the diverse phenotypes of S. aureus, ranging from a harmless colonizer to an organism capable of infecting various human organs. Emphasis will be placed on QS and its role in orchestrating S. aureus behavior across different contexts. SHORT CONCLUSION The pathophysiology of S. aureus infection is substantially influenced by phenotypic changes resulting from factors beyond Agr. Future studies are expected to give the comprehensive understanding of S. aureus overall profile in various settings.
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Affiliation(s)
- Yuriko Yamazaki
- Cutaneous Allergy and Host Defense, Immunology Frontier Research Center, Osaka, University, Osaka, 565-0871, Japan
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Tomoka Ito
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Masakazu Tamai
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Seitaro Nakagawa
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Yuumi Nakamura
- Cutaneous Allergy and Host Defense, Immunology Frontier Research Center, Osaka, University, Osaka, 565-0871, Japan.
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan.
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12
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Cheung GYC, Lee JH, Liu R, Lawhon SD, Yang C, Otto M. Methicillin Resistance Elements in the Canine Pathogen Staphylococcus pseudintermedius and Their Association with the Peptide Toxin PSM-mec. Antibiotics (Basel) 2024; 13:130. [PMID: 38391516 PMCID: PMC10886032 DOI: 10.3390/antibiotics13020130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/24/2024] Open
Abstract
Staphylococcus pseudintermedius is a frequent cause of infections in dogs. Infectious isolates of this coagulase-positive staphylococcal species are often methicillin- and multidrug-resistant, which complicates therapy. In staphylococci, methicillin resistance is encoded by determinants found on mobile genetic elements called Staphylococcal Chromosome Cassette mec (SCCmec), which, in addition to methicillin resistance factors, sometimes encode additional genes, such as further resistance factors and, rarely, virulence determinants. In this study, we analyzed SCCmec in a collection of infectious methicillin-resistant S. pseudintermedius (MRSP) isolates from predominant lineages in the United States. We found that several lineages characteristically have specific types of SCCmec elements and Agr types and harbor additional factors in their SCCmec elements that may promote virulence or affect DNA uptake. All isolates had SCCmec-encoded restriction-modification (R-M) systems of types I or II, and sequence types (STs) ST84 and ST64 had one type II and one type I R-M system, although the latter lacked a complete methylation enzyme gene. ST68 isolates also had an SCCmec-encoded CRISPR system. ST71 isolates had a psm-mec gene, which, in all but apparently Agr-dysfunctional isolates, produced a PSM-mec peptide toxin, albeit at relatively small amounts. This study gives detailed insight into the composition of SCCmec elements in infectious isolates of S. pseudintermedius and lays the genetic foundation for further efforts directed at elucidating the contribution of identified accessory SCCmec factors in impacting SCCmec-encoded and thus methicillin resistance-associated virulence and resistance to DNA uptake in this leading canine pathogen.
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Affiliation(s)
- Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Ji Hyun Lee
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Sara D Lawhon
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Ching Yang
- Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, Brookville, NY 11548, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
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13
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Sakoulas G, Nizet V. Measuring beta-lactam minimum inhibitory concentrations in Staphylococcus aureus in the clinical microbiology laboratory: pinning the tail on the donkey. J Clin Microbiol 2024; 62:e0036623. [PMID: 37966224 PMCID: PMC10793257 DOI: 10.1128/jcm.00366-23] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023] Open
Abstract
Significant shortcomings have been identified in standard methods of susceptibility testing in bacteriological media, not only because the media fails to recapitulate the in vivo environment, but susceptibility testing itself fails to capture sub-MIC effects that significantly attenuate bacterial virulence properties. Until susceptibility testing conditions better recapitulate the in vivo environment, attempts to establish the quantitative relevance of beta-lactam MIC using current clinical microbiology standards in Staphylococcus aureus infections will likely prove unsuccessful.
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Affiliation(s)
- George Sakoulas
- Sharp Rees-Stealy Medical Group, San Diego, California, USA
- UCSD School of Medicine, La Jolla, California, USA
| | - Victor Nizet
- UCSD School of Medicine, La Jolla, California, USA
- Skaggs School of Pharmacy, UCSD School of Medicine, La Jolla, California, USA
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14
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Jiang S, Chen M, Zhang J, Ba X, Zhang H, Hong Y, Sun L, Wang Z, Zhuang H, Zhu F, Chen Y, Wang H, Zhao F, Chen Y, Yu Y, Ji S. Profiling daptomycin resistance among diverse methicillin-resistant Staphylococcus aureus lineages in China. Antimicrob Agents Chemother 2023; 67:e0056323. [PMID: 37902403 PMCID: PMC10649010 DOI: 10.1128/aac.00563-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 09/15/2023] [Indexed: 10/31/2023] Open
Abstract
Daptomycin (DAP) is effective against methicillin-resistant Staphylococcus aureus (MRSA). However, reduced susceptibility to DAP in MRSA may lead to treatment failures. We aim to determine the distribution of DAP minimum inhibitory concentrations (MICs) and DAP heteroresistance (hDAP) among MRSA lineages in China. A total of 472 clinical MRSA isolates collected from 2015 to 2017 in China were examined for DAP susceptibility. All isolates (n = 472) were found to be DAP susceptible, but 35.17% (166/472) of them exhibited a high DAP MIC (MIC >0.5 µg/mL). The high DAP MIC group contained a larger proportion of isolates with a higher vancomycin or teicoplanin MIC (>1.5 µg/mL) than the low DAP MIC group (19.3% vs 7.8%, P < 0.001; 22.3% vs 8.2%, P < 0.001). We compared the clonal complex (CC) distributions and clinical characteristics in MRSA isolates stratified by DAP MIC. CC5 isolates were less susceptible to DAP (MIC50 = 1 µg/mL) than CC59 isolates (MIC50 = 0.5 µg/mL, P < 0.001). Population analysis profiling revealed that 5 of 10 ST5 and ST59 DAP-susceptible MRSA isolates investigated exhibited hDAP. The results also showed that CC5 MRSA with an agrA mutation (I238K) had a higher DAP MIC than those with a wild-type agrA (P < 0.001). The agrA-I238K mutation was found to be associated with agr dysfunction as indicated by the loss of δ-hemolysin production. In addition, agr/psmα defectiveness was associated with hDAP in MRSA. Whole-genome sequencing analysis revealed mutations in mprF and walR/walK in DAP-resistant subpopulations, and most DAP-resistant subpopulations (6/8, 75%) were stable. Our study suggests that the increased DAP resistance and hDAP in MRSA may threaten the effectiveness against MRSA infections.
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Affiliation(s)
- Shengnan Jiang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Mengzhen Chen
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Junxiong Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Xihu District Center for Disease Control and Prevention of Hangzhou, Hangzhou, China
| | - Xiaoliang Ba
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Hao Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yueqin Hong
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lu Sun
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhengan Wang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hemu Zhuang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Feiteng Zhu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yiyi Chen
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Haiping Wang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Feng Zhao
- Department of Clinical laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yan Chen
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shujuan Ji
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
- Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
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15
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Lee EH, Choi MH, Lee KH, Song YG, Han SH. Differences of clinical characteristics and outcome in proven invasive Trichosporon infections caused by asahii and non-asahii species. Mycoses 2023; 66:992-1002. [PMID: 37515448 DOI: 10.1111/myc.13635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/22/2023] [Accepted: 07/23/2023] [Indexed: 07/30/2023]
Abstract
BACKGROUND Trichosporon is an emerging yeast that causes invasive infections in immunocompromised patients experiencing prolonged hospitalisation, indwelling venous catheters and neutropenia. METHODS This retrospective observational cohort study analysed invasive Trichosporon infections (ITIs) occurring between January 2005 and December 2022 at three tertiary hospitals and compared the clinical characteristics and prognostic factors of ITIs caused by Trichosporon asahii and non-T. asahii spp. After evaluating 1067 clinical isolates, we identified 46 patients with proven ITIs, defined as cases in which Trichosporon was isolated from blood, cerebrospinal fluid, or sterile tissues. RESULTS The patients were separated into T. asahii and non-T. asahii groups containing 25 and 21 patients, respectively, all of which except one were immunocompromised. During this period, both the number of clinical isolates and patients with ITIs (mainly T. asahii) increased; whereas, cases involving non-T. asahii spp. decreased. Compared with the non-T. asahii group, the T. asahii group had more patients with multiple catheters (84% vs. 33%, p = .001) and those receiving renal replacement therapy (48% vs. 14%, p = .005). The all-cause 28-day mortality rate after ITI in the T. asahii group (44%) was significantly higher than in the non-T. asahii group (10%, Log-rank p = .014). The multivariate Cox regression model revealed that T. asahii (reference, non-T. asahii spp.; aHR = 4.3; 95% CI = 1.2-15.2, p = .024) and neutropenia for 5 days or more (aHR = 2.2, 95% CI = 1.5-3.6, p = .035) were independent factors in the 28-day mortality after ITI. CONCLUSION The proven ITIs due to T. asahii produced more unfavourable outcomes compared with ITIs caused by non-T. asahii spp.
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Affiliation(s)
- Eun Hwa Lee
- Division of Infectious Disease, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Min Hyuk Choi
- Department of Laboratory Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Kyoung Hwa Lee
- Division of Infectious Disease, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young Goo Song
- Division of Infectious Disease, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sang Hoon Han
- Division of Infectious Disease, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
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16
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Li Y, Zhu F, Manna AC, Chen L, Jiang J, Hong JI, Proctor RA, Bayer AS, Cheung AL, Xiong YQ. Gp05, a Prophage-Encoded Virulence Factor, Contributes to Persistent Methicillin-Resistant Staphylococcus aureus Endovascular Infection. Microbiol Spectr 2023; 11:e0060023. [PMID: 37358448 PMCID: PMC10434118 DOI: 10.1128/spectrum.00600-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/24/2023] [Indexed: 06/27/2023] Open
Abstract
Persistent methicillin-resistant Staphylococcus aureus (MRSA) endovascular infections represent a serious public health threat. We recently demonstrated that the presence of a novel prophage ϕSA169 was associated with vancomycin (VAN) treatment failure in experimental MRSA endocarditis. In this study, we assessed the role of a ϕSA169 gene, ϕ80α_gp05 (gp05), in VAN-persistent outcome using gp05 isogenic MRSA strain sets. Of note, Gp05 significantly influences the intersection of MRSA virulence factors, host immune responses, and antibiotic treatment efficacy, including the following: (i) activity of the significant energy-yielding metabolic pathway (e.g., tricarboxylic acid cycle); (ii) carotenoid pigment production; (iii) (p)ppGpp (guanosine tetra- and pentaphosphate) production, which activates the stringent response and subsequent downstream functional factors (e.g., phenol-soluble modulins and polymorphonuclear neutrophil bactericidal activity); and (iv) persistence to VAN treatment in an experimental infective endocarditis model. These data suggest that Gp05 is a significant virulence factor which contributes to the persistent outcomes in MRSA endovascular infection by multiple pathways. IMPORTANCE Persistent endovascular infections are often caused by MRSA strains that are susceptible to anti-MRSA antibiotics in vitro by CLSI breakpoints. Thus, the persistent outcome represents a unique variant of traditional antibiotic resistance mechanisms and a significant therapeutic challenge. Prophage, a critical mobile genetic element carried by most MRSA isolates, provides their bacterial host with metabolic advantages and resistance mechanisms. However, how prophage-encoded virulence factors interact with the host defense system and antibiotics, driving the persistent outcome, is not well known. In the current study, we demonstrated that a novel prophage gene, gp05, significantly impacts tricarboxylic acid cycle activity, stringent response, and pigmentation, as well as vancomycin treatment outcome in an experimental endocarditis model using isogenic gp05 overexpression and chromosomal deletion mutant MRSA strain sets. The findings significantly advance our understanding of the role of Gp05 in persistent MRSA endovascular infection and provide a potential target for development of novel drugs against these life-threatening infections.
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Affiliation(s)
- Yi Li
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Fengli Zhu
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Adhar C. Manna
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Liang Chen
- Center for Discovery and Innovation, Nutley, New Jersey, USA
| | - Jason Jiang
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Jong-In Hong
- Department of Chemistry, Seoul National University, Seoul, South Korea
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Arnold S. Bayer
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Ambrose L. Cheung
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Yan Q. Xiong
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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17
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Hsieh RC, Liu R, Burgin DJ, Otto M. Understanding mechanisms of virulence in MRSA: implications for antivirulence treatment strategies. Expert Rev Anti Infect Ther 2023; 21:911-928. [PMID: 37501364 DOI: 10.1080/14787210.2023.2242585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 07/26/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION Methicillin-resistant Staphylococcus aureus (MRSA) is a widespread pathogen, often causing recurrent and deadly infections in the hospital and community. Many S. aureus virulence factors have been suggested as potential targets for antivirulence therapy to decrease the threat of diminishing antibiotic availability. Antivirulence methods hold promise due to their adjunctive and prophylactic potential and decreased risk for selective pressure. AREAS COVERED This review describes the dominant virulence mechanisms exerted by MRSA and antivirulence therapeutics that are currently undergoing testing in clinical or preclinical stages. We also discuss the advantages and downsides of several investigational antivirulence approaches, including the targeting of bacterial transporters, host-directed therapy, and quorum-sensing inhibitors. For this review, a systematic search of literature on PubMed, Google Scholar, and Web of Science for relevant search terms was performed in April and May 2023. EXPERT OPINION Vaccine and antibody strategies have failed in clinical trials and could benefit from more basic science-informed approaches. Antivirulence-targeting approaches need to be set up better to meet the requirements of drug development, rather than only providing limited results to provide 'proof-of-principle' translational value of pathogenesis research. Nevertheless, there is great potential of such strategies and potential particular promise for novel probiotic approaches.
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Affiliation(s)
- Roger C Hsieh
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Dylan J Burgin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
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18
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Patel H, Rawat S. A genetic regulatory see-saw of biofilm and virulence in MRSA pathogenesis. Front Microbiol 2023; 14:1204428. [PMID: 37434702 PMCID: PMC10332168 DOI: 10.3389/fmicb.2023.1204428] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/30/2023] [Indexed: 07/13/2023] Open
Abstract
Staphylococcus aureus is one of the most common opportunistic human pathogens causing several infectious diseases. Ever since the emergence of the first methicillin-resistant Staphylococcus aureus (MRSA) strain decades back, the organism has been a major cause of hospital-acquired infections (HA-MRSA). The spread of this pathogen across the community led to the emergence of a more virulent subtype of the strain, i.e., Community acquired Methicillin resistant Staphylococcus aureus (CA-MRSA). Hence, WHO has declared Staphylococcus aureus as a high-priority pathogen. MRSA pathogenesis is remarkable because of the ability of this "superbug" to form robust biofilm both in vivo and in vitro by the formation of polysaccharide intercellular adhesin (PIA), extracellular DNA (eDNA), wall teichoic acids (WTAs), and capsule (CP), which are major components that impart stability to a biofilm. On the other hand, secretion of a diverse array of virulence factors such as hemolysins, leukotoxins, enterotoxins, and Protein A regulated by agr and sae two-component systems (TCS) aids in combating host immune response. The up- and downregulation of adhesion genes involved in biofilm formation and genes responsible for synthesizing virulence factors during different stages of infection act as a genetic regulatory see-saw in the pathogenesis of MRSA. This review provides insight into the evolution and pathogenesis of MRSA infections with a focus on genetic regulation of biofilm formation and virulence factors secretion.
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Affiliation(s)
| | - Seema Rawat
- Microbiology Laboratory, School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India
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19
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Otto M, Dickey SW, Wolz C. Editorial: Quorum-sensing in Gram-positive pathogens - mechanisms, role in infection, and potential as a therapeutic target. Front Cell Infect Microbiol 2023; 13:1236705. [PMID: 37404725 PMCID: PMC10315904 DOI: 10.3389/fcimb.2023.1236705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 07/06/2023] Open
Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, United States
| | - Seth W. Dickey
- Department of Veterinary Medicine, University of Maryland, College Park, MD, United States
- Virginia-Maryland College of Veterinary Medicine, College Park, MD, United States
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
- Cluster of Excellence EXC 2124 “Controlling Microbes to Fight Infections”, University of Tübingen, Tübingen, Germany
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20
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Hachani A, Giulieri SG, Guérillot R, Walsh CJ, Herisse M, Soe YM, Baines SL, Thomas DR, Cheung SD, Hayes AS, Cho E, Newton HJ, Pidot S, Massey RC, Howden BP, Stinear TP. A high-throughput cytotoxicity screening platform reveals agr-independent mutations in bacteraemia-associated Staphylococcus aureus that promote intracellular persistence. eLife 2023; 12:e84778. [PMID: 37289634 PMCID: PMC10259494 DOI: 10.7554/elife.84778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 05/23/2023] [Indexed: 06/10/2023] Open
Abstract
Staphylococcus aureus infections are associated with high mortality rates. Often considered an extracellular pathogen, S. aureus can persist and replicate within host cells, evading immune responses, and causing host cell death. Classical methods for assessing S. aureus cytotoxicity are limited by testing culture supernatants and endpoint measurements that do not capture the phenotypic diversity of intracellular bacteria. Using a well-established epithelial cell line model, we have developed a platform called InToxSa (intracellular toxicity of S. aureus) to quantify intracellular cytotoxic S. aureus phenotypes. Studying a panel of 387 S. aureus bacteraemia isolates, and combined with comparative, statistical, and functional genomics, our platform identified mutations in S. aureus clinical isolates that reduced bacterial cytotoxicity and promoted intracellular persistence. In addition to numerous convergent mutations in the Agr quorum sensing system, our approach detected mutations in other loci that also impacted cytotoxicity and intracellular persistence. We discovered that clinical mutations in ausA, encoding the aureusimine non-ribosomal peptide synthetase, reduced S. aureus cytotoxicity, and increased intracellular persistence. InToxSa is a versatile, high-throughput cell-based phenomics platform and we showcase its utility by identifying clinically relevant S. aureus pathoadaptive mutations that promote intracellular residency.
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Affiliation(s)
- Abderrahman Hachani
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Stefano G Giulieri
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Romain Guérillot
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Calum J Walsh
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Marion Herisse
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Ye Mon Soe
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Sarah L Baines
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - David R Thomas
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
- Infection and Immunity Program, Department of Microbiology and Biomedicine Discovery Institute, Monash UniversityClaytonAustralia
| | - Shane Doris Cheung
- Biological Optical Microscopy Platform, University of MelbourneMelbourneAustralia
| | - Ashleigh S Hayes
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Ellie Cho
- Biological Optical Microscopy Platform, University of MelbourneMelbourneAustralia
| | - Hayley J Newton
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
- Infection and Immunity Program, Department of Microbiology and Biomedicine Discovery Institute, Monash UniversityClaytonAustralia
| | - Sacha Pidot
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Ruth C Massey
- School of Microbiology, University College CorkCorkIreland
- School of Medicine, University College CorkCorkIreland
- APC Microbiome Ireland, University College CorkCorkIreland
- School of Cellular and Molecular Medicine, University of BristolBristolUnited Kingdom
| | - Benjamin P Howden
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, Doherty Institute, University of MelbourneMelbourneAustralia
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21
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He L, Lv H, Wang Y, Jiang F, Liu Q, Zhang F, Wang H, Shen H, Otto M, Li M. Antibiotic treatment can exacerbate biofilm-associated infection by promoting quorum cheater development. NPJ Biofilms Microbiomes 2023; 9:26. [PMID: 37202425 DOI: 10.1038/s41522-023-00394-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 04/27/2023] [Indexed: 05/20/2023] Open
Abstract
Quorum cheating, a socio-microbiological process that is based on mutations in cell density-sensing (quorum-sensing) systems, has emerged as an important contributor to biofilm-associated infection in the leading human pathogen Staphylococcus aureus. This is because inactivation of the staphylococcal Agr quorum-sensing system leads to pronounced biofilm formation, increasing resistance to antibiotics and immune defense mechanisms. Since biofilm infections in the clinic usually progress under antibiotic treatment, we here investigated whether such treatment promotes biofilm infection via the promotion of quorum cheating. Quorum cheater development was stimulated by several antibiotics used in the treatment of staphylococcal biofilm infections more strongly in biofilm than in the planktonic mode of growth. Sub-inhibitory concentrations of levofloxacin and vancomycin were investigated for their impact on biofilm-associated (subcutaneous catheter-associated and prosthetic joint-associated infection), where in contrast to a non-biofilm-associated subcutaneous skin infection model, a significant increase of the bacterial load and development of agr mutants was observed. Our results directly demonstrate the development of Agr dysfunctionality in animal biofilm-associated infection models and reveal that inappropriate antibiotic treatment can be counterproductive for such infections as it promotes quorum cheating and the associated development of biofilms.
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Affiliation(s)
- Lei He
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Shanghai, 200127, China
| | - Huiying Lv
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Shanghai, 200127, China
| | - Yanan Wang
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Shanghai, 200127, China
| | - Feng Jiang
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China
| | - Qian Liu
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Shanghai, 200127, China
| | - Feiyang Zhang
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China
| | - Hua Wang
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Shanghai, 200127, China
| | - Hao Shen
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, China
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD, 20814, USA.
| | - Min Li
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Shanghai, 200127, China.
- Faculty of Medical Laboratory Science, Shanghai Jiao Tong University School of Medicine, 227 South Chongqing Road, Shanghai, 200025, China.
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22
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Müller MM, Baldauf C, Hornischer S, Klassert TE, Schneegans A, Behnert A, Pletz MW, Hagel S, Slevogt H. Staphylococcus aureus induces tolerance in human monocytes accompanied with expression changes of cell surface markers. Front Immunol 2023; 14:1046374. [PMID: 37063823 PMCID: PMC10104166 DOI: 10.3389/fimmu.2023.1046374] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 03/16/2023] [Indexed: 04/03/2023] Open
Abstract
Exposure of human monocytes to lipopolysaccharide (LPS) or other pathogen-associated molecular pattern (PAMPs) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance (ET), associated with the pathogenesis of sepsis. In this study, we aimed to characterize the cellular state of human monocytes from healthy donors stimulated with Staphylococcus aureus in comparison to TLR2-specific ligands. We analyzed S. aureus induced gene expression changes after 2 and 24 hours by amplicon sequencing (RNA-AmpliSeq) and compared the pro-inflammatory response after 2 hours with the response in re-stimulation experiments. In parallel, glycoprotein expression changes in human monocytes after 24 hours of S. aureus stimulation were analyzed by proteomics and compared to stimulation experiments with TLR2 ligands Malp-2 and Pam3Cys and TLR4 ligand LPS. Finally, we analyzed peripheral blood monocytes of patients with S. aureus bloodstream infection for their ex vivo inflammatory responses towards S. aureus stimulation and their glycoprotein expression profiles. Our results demonstrate that monocytes from healthy donors stimulated with S. aureus and TLR ligands of Gram-positive bacteria entered the tolerant cell state after activation similar to LPS treatment. In particular reduced gene expression of pro-inflammatory cytokines (TNF, IL1β) and chemokines (CCL20, CCL3, CCL4, CXCL2, CXCL3 and CXCL8) could be demonstrated. Glycoprotein expression changes in monocytes tolerized by the different TLR agonists were highly similar while S. aureus-stimulated monocytes shared some of the PAMP-induced changes but also exhibited a distinct expression profile. 11 glycoproteins (CD44, CD274, DSC2, ICAM1, LAMP3, LILRB1, PTGS2, SLC1A3, CR1, FGL2, and HP) were similarly up- or downregulated in all four comparisons in the tolerant cell state. Monocytes from patients with S. aureus bacteremia revealed preserved pro-inflammatory responsiveness to S. aureus stimulation ex vivo, expressed increased CD44 mRNA but no other glycoprotein of the tolerance signature was differentially expressed.
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Affiliation(s)
- Mario M. Müller
- Septomics Research Center, Jena University Hospital, Jena, Germany
- Integrated Research and Treatment Center - Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | | | | | - Tilman E. Klassert
- Septomics Research Center, Jena University Hospital, Jena, Germany
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
| | | | - Andrea Behnert
- Septomics Research Center, Jena University Hospital, Jena, Germany
- Integrated Research and Treatment Center - Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Mathias W. Pletz
- Institute for Infectious Diseases and Infection Control, Jena University Hospital – Friedrich Schiller University Jena, Jena, Germany
| | - Stefan Hagel
- Institute for Infectious Diseases and Infection Control, Jena University Hospital – Friedrich Schiller University Jena, Jena, Germany
| | - Hortense Slevogt
- Septomics Research Center, Jena University Hospital, Jena, Germany
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- *Correspondence: Hortense Slevogt,
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23
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Parsons JB, Westgeest AC, Conlon BP, Fowler VG. Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia: Host, Pathogen, and Treatment. Antibiotics (Basel) 2023; 12:455. [PMID: 36978320 PMCID: PMC10044482 DOI: 10.3390/antibiotics12030455] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/18/2023] [Accepted: 02/20/2023] [Indexed: 03/02/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a devastating pathogen responsible for a variety of life-threatening infections. A distinctive characteristic of this pathogen is its ability to persist in the bloodstream for several days despite seemingly appropriate antibiotics. Persistent MRSA bacteremia is common and is associated with poor clinical outcomes. The etiology of persistent MRSA bacteremia is a result of the complex interplay between the host, the pathogen, and the antibiotic used to treat the infection. In this review, we explore the factors related to each component of the host-pathogen interaction and discuss the clinical relevance of each element. Next, we discuss the treatment options and diagnostic approaches for the management of persistent MRSA bacteremia.
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Affiliation(s)
- Joshua B. Parsons
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Annette C. Westgeest
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Department of Infectious Diseases, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Vance G. Fowler
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Duke Clinical Research Institute, Durham, NC 27710, USA
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24
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Otto M. Critical Assessment of the Prospects of Quorum-Quenching Therapy for Staphylococcus aureus Infection. Int J Mol Sci 2023; 24:ijms24044025. [PMID: 36835436 PMCID: PMC9958572 DOI: 10.3390/ijms24044025] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/04/2023] [Accepted: 02/08/2023] [Indexed: 02/19/2023] Open
Abstract
Staphylococcus aureus is an important pathogen that causes a high number of infections and is one of the leading causes of death in hospitalized patients. Widespread antibiotic resistance such as in methicillin-resistant S. aureus (MRSA) has prompted research into potential anti-virulence-targeted approaches. Targeting the S. aureus accessory gene regulator (Agr) quorum-sensing system, a master regulator of virulence, is the most frequently proposed anti-virulence strategy for S. aureus. While much effort has been put into the discovery and screening for Agr inhibitory compounds, in vivo analysis of their efficacy in animal infection models is still rare and reveals various shortcomings and problems. These include (i) an almost exclusive focus on topical skin infection models, (ii) technical problems that leave doubt as to whether observed in vivo effects are due to quorum-quenching, and (iii) the discovery of counterproductive biofilm-increasing effects. Furthermore, potentially because of the latter, invasive S. aureus infection is associated with Agr dysfunctionality. Altogether, the potential of Agr inhibitory drugs is nowadays seen with low enthusiasm given the failure to provide sufficient in vivo evidence for their potential after more than two decades since the initiation of such efforts. However, current Agr inhibition-based probiotic approaches may lead to a new application of Agr inhibition strategies in preventing S. aureus infections by targeting colonization or for otherwise difficult-to-treat skin infections such as atopic dermatitis.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
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25
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Dyzenhaus S, Sullivan MJ, Alburquerque B, Boff D, van de Guchte A, Chung M, Fulmer Y, Copin R, Ilmain JK, O'Keefe A, Altman DR, Stubbe FX, Podkowik M, Dupper AC, Shopsin B, van Bakel H, Torres VJ. MRSA lineage USA300 isolated from bloodstream infections exhibit altered virulence regulation. Cell Host Microbe 2023; 31:228-242.e8. [PMID: 36681080 PMCID: PMC9911362 DOI: 10.1016/j.chom.2022.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/18/2022] [Accepted: 12/02/2022] [Indexed: 01/22/2023]
Abstract
The epidemic community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300 lineage has recently become a leading cause of hospital-associated bloodstream infections (BSIs). Here, we leveraged this recent introduction into hospitals and the limited genetic variation across USA300 isolates to identify mutations that contribute to its success in a new environment. We found that USA300 BSI isolates exhibit altered virulence regulation. Using comparative genomics to delineate the genes involved in this phenotype, we discovered repeated and independent mutations in the transcriptional regulator sarZ. Mutations in sarZ resulted in increased virulence of USA300 BSI isolates in a murine model of BSI. The sarZ mutations derepressed the expression and production of the surface protein ClfB, which was critical for the pathogenesis of USA300 BSI isolates. Altogether, these findings highlight ongoing evolution of a major MRSA lineage and suggest USA300 strains can optimize their fitness through altered regulation of virulence.
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Affiliation(s)
- Sophie Dyzenhaus
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Mitchell J Sullivan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bremy Alburquerque
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Daiane Boff
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Adriana van de Guchte
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Marilyn Chung
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yi Fulmer
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Richard Copin
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Juliana K Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Anna O'Keefe
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Deena R Altman
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - François-Xavier Stubbe
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Magdalena Podkowik
- Division of Infectious Diseases and Immunology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Amy C Dupper
- Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bo Shopsin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Division of Infectious Diseases and Immunology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Harm van Bakel
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA.
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26
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MRSA Isolates from Patients with Persistent Bacteremia Generate Nonstable Small Colony Variants In Vitro within Macrophages and Endothelial Cells during Prolonged Vancomycin Exposure. Infect Immun 2023; 91:e0042322. [PMID: 36602380 PMCID: PMC9872686 DOI: 10.1128/iai.00423-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Staphylococcus aureus (especially methicillin-resistant S. aureus [MRSA]) is frequently associated with persistent bacteremia (PB) during vancomycin therapy despite consistent susceptibility in vitro. Strategic comparisons of PB strains versus those from vancomycin-resolving bacteremia (RB) would yield important mechanistic insights into PB outcomes. Clinical PB versus RB isolates were assessed in vitro for intracellular replication and small colony variant (SCV) formation within macrophages and endothelial cells (ECs) in the presence or absence of exogenous vancomycin. In both macrophages and ECs, PB and RB isolates replicated within lysosome-associated membrane protein-1 (LAMP-1)-positive compartments. PB isolates formed nonstable small colony variants (nsSCVs) in vancomycin-exposed host cells at a significantly higher frequency than matched RB isolates (in granulocyte-macrophage colony-stimulating factor [GM-CSF], human macrophages PB versus RB, P < 0.0001 at 48 h; in ECs, PB versus RB, P < 0.0001 at 24 h). This phenotype could represent one potential basis for the unique ability of PB isolates to adaptively resist vancomycin therapy and cause PB in humans. Elucidating the molecular mechanism(s) by which PB strains form nsSCVs could facilitate the discovery of novel treatment strategies to mitigate PB due to MRSA.
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27
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In Silico Genome-Scale Analysis of Molecular Mechanisms Contributing to the Development of a Persistent Infection with Methicillin-Resistant Staphylococcus aureus (MRSA) ST239. Int J Mol Sci 2022; 23:ijms232416086. [PMID: 36555727 PMCID: PMC9781258 DOI: 10.3390/ijms232416086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/05/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
The increasing frequency of isolation of methicillin-resistant Staphylococcus aureus (MRSA) limits the chances for the effective antibacterial therapy of staphylococcal diseases and results in the development of persistent infection such as bacteremia and osteomyelitis. The aim of this study was to identify features of the MRSAST239 0943-1505-2016 (SA943) genome that contribute to the formation of both acute and chronic musculoskeletal infections. The analysis was performed using comparative genomics data of the dominant epidemic S. aureus lineages, namely ST1, ST8, ST30, ST36, and ST239. The SA943 genome encodes proteins that provide resistance to the host's immune system, suppress immunological memory, and form biofilms. The molecular mechanisms of adaptation responsible for the development of persistent infection were as follows: amino acid substitution in PBP2 and PBP2a, providing resistance to ceftaroline; loss of a large part of prophage DNA and restoration of the nucleotide sequence of beta-hemolysin, that greatly facilitates the escape of phagocytosed bacteria from the phagosome and formation of biofilms; dysfunction of the AgrA system due to the presence of psm-mec and several amino acid substitutions in the AgrC; partial deletion of the nucleotide sequence in genomic island vSAβ resulting in the loss of two proteases of Spl-operon; and deletion of SD repeats in the SdrE amino acid sequence.
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28
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Holland TL, Bayer AS, Fowler VG. Persistent Methicilin-Resistant Staphylococcus aureus Bacteremia: Resetting the Clock for Optimal Management. Clin Infect Dis 2022; 75:1668-1674. [PMID: 35535790 PMCID: PMC9617577 DOI: 10.1093/cid/ciac364] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Indexed: 01/25/2023] Open
Abstract
A positive follow-up blood culture for methicillin-resistant Staphylococcus aureus (MRSA) while on seemingly appropriate therapy is a common and ominous development. However, the definition and management of persistent MRSA bacteremia is unstandardized. In this Opinion Paper, we identify the presence of bacteremia for > 1 calendar day as a "worry point" that should trigger an intensive diagnostic evaluation to identify metastatic infection sites. Next, we define the duration of MRSA bacteremia that likely constitutes antibiotic failure and outline a potential management algorithm for such patients. Finally, we propose pragmatic clinical trial designs to test treatment strategies for persistent MRSA bacteremia.
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Affiliation(s)
- Thomas L Holland
- Department of Medicine, Duke University, Durham, North Carolina, USA
- Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Arnold S Bayer
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA, Torrance, California, USA
- The Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Vance G Fowler
- Department of Medicine, Duke University, Durham, North Carolina, USA
- Duke Clinical Research Institute, Durham, North Carolina, USA
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29
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Staphylococcus lugdunensis Uses the Agr Regulatory System to Resist Killing by Host Innate Immune Effectors. Infect Immun 2022; 90:e0009922. [PMID: 36069592 PMCID: PMC9584346 DOI: 10.1128/iai.00099-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Coagulase-negative staphylococci (CoNS) are frequently commensal bacteria that rarely cause disease in mammals. Staphylococcus lugdunensis is an exceptional CoNS that causes disease in humans similar to virulent Staphylococcus aureus, but the factors that enhance the virulence of this bacterium remain ill defined. Here, we used random transposon insertion mutagenesis to identify the agr quorum sensing system as a regulator of hemolysins in S. lugdunensis. Using RNA sequencing (RNA-seq), we revealed that agr regulates dozens of genes, including hemolytic S. lugdunensis synergistic hemolysins (SLUSH) peptides and the protease lugdulysin. A murine bacteremia model was used to show that mice infected systemically with wild-type S. lugdunensis do not show overt signs of disease despite there being high numbers of bacteria in the livers and kidneys of mice. Moreover, proliferation of the agr mutant in these organs was no different from that of the wild-type strain, leaving the role of the SLUSH peptides and the metalloprotease lugdulysin in pathogenesis still unclear. Nonetheless, the tropism of S. lugdunensis for humans led us to investigate the role of virulence factors in other ways. We show that agr-regulated effectors, but not SLUSH or lugdulysin alone, are important for S. lugdunensis survival in whole human blood. Moreover, we demonstrate that Agr contributes to survival of S. lugdunensis during encounters with murine and primary human macrophages. These findings demonstrate that, in S. lugdunensis, Agr regulates expression of virulence factors and is required for resistance to host innate antimicrobial defenses. This study therefore provides insight into strategies that this Staphylococcus species uses to cause disease.
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Transcriptome Analyses of Prophage in Mediating Persistent Methicillin-Resistant Staphylococcus aureus Endovascular Infection. Genes (Basel) 2022; 13:genes13091527. [PMID: 36140695 PMCID: PMC9498598 DOI: 10.3390/genes13091527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 12/24/2022] Open
Abstract
Persistent methicillin-resistant Staphylococcus aureus (MRSA) endovascular infections represent a significant subset of S. aureus infections and correlate with exceptionally high mortality. We have recently demonstrated that the lysogenization of prophage ϕSA169 from a clinical persistent MRSA bacteremia isolate (300-169) into a clinical resolving bacteremia MRSA isolate (301-188) resulted in the acquisition of well-defined in vitro and in vivo phenotypic and genotypic profiles related to persistent outcome. However, the underlying mechanism(s) of this impact is unknown. In the current study, we explored the genetic mechanism that may contribute to the ϕSA169-correlated persistence using RNA sequencing. Transcriptomic analyses revealed that the most significant impacts of ϕSA169 were: (i) the enhancement of fatty acid biosynthesis and purine and pyrimidine metabolic pathways; (ii) the repression of galactose metabolism and phosphotransferase system (PTS); and (iii) the down-regulation of the mutual prophage genes in both 300-169 and 301-188 strains. In addition, the influence of different genetic backgrounds between 300-169 and 301-188 might also be involved in the persistent outcome. These findings may provide targets for future studies on the persistence of MRSA.
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Genomic Study on Blood Culture Isolates From Patients With Staphylococcus Infection-associated Glomerulonephritis. Kidney Int Rep 2022; 7:2264-2278. [PMID: 36217522 PMCID: PMC9546744 DOI: 10.1016/j.ekir.2022.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/05/2022] [Accepted: 07/11/2022] [Indexed: 11/23/2022] Open
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Horká M, Růžička F, Siváková A, Karásek P, Šalplachta J, Pantůček R, Roth M. Capillary electrophoretic methods for classification of methicillin-resistant Staphylococcus aureus (MRSA) clones. Anal Chim Acta 2022; 1227:340305. [DOI: 10.1016/j.aca.2022.340305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/19/2022] [Accepted: 08/20/2022] [Indexed: 11/26/2022]
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Menard G, Silard C, Suriray M, Rouillon A, Augagneur Y. Thirty Years of sRNA-Mediated Regulation in Staphylococcus aureus: From Initial Discoveries to In Vivo Biological Implications. Int J Mol Sci 2022; 23:ijms23137346. [PMID: 35806357 PMCID: PMC9266662 DOI: 10.3390/ijms23137346] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/20/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Staphylococcus aureus is a widespread livestock and human pathogen that colonizes diverse microenvironments within its host. Its adaptation to the environmental conditions encountered within humans relies on coordinated gene expression. This requires a sophisticated regulatory network, among which regulatory RNAs (usually called sRNAs) have emerged as key players over the last 30 years. In S. aureus, sRNAs regulate target genes at the post-transcriptional level through base–pair interactions. The functional characterization of a subset revealed that they participate in all biological processes, including virulence, metabolic adaptation, and antibiotic resistance. In this review, we report 30 years of S. aureus sRNA studies, from their discovery to the in-depth characterizations of some of them. We also discuss their actual in vivo contribution, which is still lagging behind, and their place within the complex regulatory network. These shall be key aspects to consider in order to clearly uncover their in vivo biological functions.
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Affiliation(s)
- Guillaume Menard
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Chloé Silard
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Marie Suriray
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Astrid Rouillon
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Yoann Augagneur
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
- Correspondence: ; Tel.: +33-223234631
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La YJ, Kim HR, Oh DH, Ahn JY, Kim YC. Comparison of Clinical Outcomes for Glycopeptides and Beta-Lactams in Methicillin-Susceptible Staphylococcus Aureus Bloodstream Infections. Yonsei Med J 2022; 63:611-618. [PMID: 35748072 PMCID: PMC9226830 DOI: 10.3349/ymj.2022.63.7.611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/05/2022] [Accepted: 04/20/2022] [Indexed: 11/27/2022] Open
Abstract
PURPOSE This study aimed to provide compelling evidence of anti-staphylococcal beta-lactam use for methicillin-susceptible Staphylococcus aureus bloodstream infection (MSSA BSI). MATERIALS AND METHODS We retrospectively collected data on patients with MSSA BSI who were admitted to two academic tertiary-care hospitals from 2010 to 2018. Only patients who received nafcillin, cefazolin, vancomycin, or teicoplanin as definitive therapy were included. The primary outcome was 28-day mortality. To perform unbiased comparisons between both treatments, we used inverse probability of treatment weighting (IPTW) analysis. RESULTS A total of 359 patients were divided into two groups based on the definitive therapy used: beta-lactams (n=203), including nafcillin or cefazolin; and glycopeptides (n=156), including vancomycin or teicoplanin. In the IPTW analysis, glycopeptides were associated with significantly increased odds of 28-day mortality (adjusted odds ratio, 3.37; 95% confidence interval, 1.71-6.61; p<0.001). The rate of primary outcome in prespecified subgroups was largely consistent with the main analysis. CONCLUSION Definitive therapy with beta-lactams in patients with MSSA BSI was associated with lower 28-day mortality compared to definitive therapy with glycopeptides.
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Affiliation(s)
- Yeon Ju La
- Department of Internal Medicine, Kangwon National University Hospital, Chuncheon, Korea
| | - Hye Rim Kim
- Biostatistics Collaboration Unit, Department of Biomedical Systems Informatics, Yonsei University College of Medicine, Seoul, Korea
| | - Dong Hyun Oh
- Department of Internal Medicine, Seoul Medical Center, Seoul, Korea
| | - Jin Young Ahn
- Division of Infectious Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
| | - Yong Chan Kim
- Department of Internal Medicine, Division of Infectious Disease, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Korea.
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He L, Zhang F, Jian Y, Lv H, Hamushan M, Liu J, Liu Y, Wang H, Tang J, Han P, Burgin DJ, Dickey SW, Shen H, Li M, Otto M. Key role of quorum-sensing mutations in the development of Staphylococcus aureus clinical device-associated infection. Clin Transl Med 2022; 12:e801. [PMID: 35389566 PMCID: PMC8989080 DOI: 10.1002/ctm2.801] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/17/2022] [Accepted: 03/22/2022] [Indexed: 11/11/2022] Open
Affiliation(s)
- Lei He
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Feiyang Zhang
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Ying Jian
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huiying Lv
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Musha Hamushan
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Junlan Liu
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yao Liu
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hua Wang
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin Tang
- Clinical Laboratory Department, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Pei Han
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Dylan J Burgin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Seth W Dickey
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Hao Shen
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Department of Orthopedics, Jinjiang Municipal Hospital, Fujian, China
| | - Min Li
- Department of Laboratory Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Faculty of Medical Laboratory Science, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
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Raghuram V, Alexander AM, Loo HQ, Petit RA, Goldberg JB, Read TD. Species-Wide Phylogenomics of the Staphylococcus aureus Agr Operon Revealed Convergent Evolution of Frameshift Mutations. Microbiol Spectr 2022; 10:e0133421. [PMID: 35044202 PMCID: PMC8768832 DOI: 10.1128/spectrum.01334-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/03/2022] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is a prominent nosocomial pathogen that causes several life-threatening diseases, such as pneumonia and bacteremia. S. aureus modulates the expression of its arsenal of virulence factors through sensing and integrating responses to environmental signals. The agr (accessory gene regulator) quorum sensing (QS) system is a major regulator of virulence phenotypes in S. aureus. There are four agr specificity groups each with a different autoinducer peptide sequence encoded by the agrD gene. Although agr is critical for the expression of many toxins, paradoxically, S. aureus strains often have nonfunctional agr activity due to loss-of-function mutations in the four-gene agr operon. To understand patterns in agr variability across S. aureus, we undertook a species-wide genomic investigation. We developed a software tool (AgrVATE; https://github.com/VishnuRaghuram94/AgrVATE) for typing and detecting frameshift mutations in the agr operon. In an analysis of over 40,000 S. aureus genomes, we showed a close association between agr type and S. aureus clonal complex. We also found a strong linkage between agrBDC alleles (encoding the peptidase, autoinducing peptide itself, and peptide sensor, respectively) but not agrA (encoding the response regulator). More than 5% of the genomes were found to have frameshift mutations in the agr operon. While 52% of these frameshifts occurred only once in the entire species, we observed cases where the recurring mutations evolved convergently across different clonal lineages with no evidence of long-term phylogenetic transmission, suggesting that strains with agr frameshifts were evolutionarily short-lived. Overall, genomic analysis of agr operon suggests evolution through multiple processes with functional consequences that are not fully understood. IMPORTANCE Staphylococcus aureus is a globally pervasive pathogen that produces a plethora of toxic molecules that can harm host immune cells. Production of these toxins is mainly controlled by an active agr quorum-sensing system, which senses and responds to bacterial cell density. However, there are many reports of S. aureus strains with genetic changes leading to impaired agr activity that are often found during chronic bloodstream infections and may be associated with increased disease severity. We developed an open-source software called AgrVATE to type agr systems and identify mutations. We used AgrVATE for a species-wide genomic survey of S. aureus, finding that more than 5% of strains in the public database had nonfunctional agr systems. We also provided new insights into the evolution of these genetic mutations in the agr system. Overall, this study contributes to our understanding of a common but relatively understudied means of virulence regulation in S. aureus.
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Affiliation(s)
- Vishnu Raghuram
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Ashley M. Alexander
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Hui Qi Loo
- Department of Biology, Emory University, Atlanta, Georgia, USA
| | - Robert A. Petit
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA
| | - Joanna B. Goldberg
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Timothy D. Read
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA
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New Mechanistic Insights into Purine Biosynthesis with Second Messenger c-di-AMP in Relation to Biofilm-Related Persistent Methicillin-Resistant Staphylococcus aureus Infections. mBio 2021; 12:e0208121. [PMID: 34724823 PMCID: PMC8561390 DOI: 10.1128/mbio.02081-21] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Persistent methicillin-resistant Staphylococcus aureus (MRSA) endovascular infections represent a significant clinically challenging subset of invasive, life-threatening S. aureus infections. We have recently demonstrated that purine biosynthesis plays an important role in such persistent infections. Cyclic di-AMP (c-di-AMP) is an essential and ubiquitous second messenger that regulates many cellular pathways in bacteria. However, whether there is a regulatory connection between the purine biosynthesis pathway and c-di-AMP impacting persistent outcomes was not known. Here, we demonstrated that the purine biosynthesis mutant MRSA strain, the ΔpurF strain (compared to its isogenic parental strain), exhibited the following significant differences in vitro: (i) lower ADP, ATP, and c-di-AMP levels; (ii) less biofilm formation with decreased extracellular DNA (eDNA) levels and Triton X-100-induced autolysis paralleling enhanced expressions of the biofilm formation-related two-component regulatory system lytSR and its downstream gene lrgB; (iii) increased vancomycin (VAN)-binding and VAN-induced lysis; and (iv) decreased wall teichoic acid (WTA) levels and expression of the WTA biosynthesis-related gene, tarH. Substantiating these data, the dacA (encoding diadenylate cyclase enzyme required for c-di-AMP synthesis) mutant strain (dacAG206S strain versus its isogenic wild-type MRSA and dacA-complemented strains) showed significantly decreased c-di-AMP levels, similar in vitro effects as seen above for the purF mutant and hypersusceptible to VAN treatment in an experimental biofilm-related MRSA endovascular infection model. These results reveal an important intersection between purine biosynthesis and c-di-AMP that contributes to biofilm-associated persistence in MRSA endovascular infections. This signaling pathway represents a logical therapeutic target against persistent MRSA infections.
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Cheung GYC, Bae JS, Otto M. Pathogenicity and virulence of Staphylococcus aureus. Virulence 2021; 12:547-569. [PMID: 33522395 PMCID: PMC7872022 DOI: 10.1080/21505594.2021.1878688] [Citation(s) in RCA: 649] [Impact Index Per Article: 162.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus is one of the most frequent worldwide causes of morbidity and mortality due to an infectious agent. This pathogen can cause a wide variety of diseases, ranging from moderately severe skin infections to fatal pneumonia and sepsis. Treatment of S. aureus infections is complicated by antibiotic resistance and a working vaccine is not available. There has been ongoing and increasing interest in the extraordinarily high number of toxins and other virulence determinants that S. aureus produces and how they impact disease. In this review, we will give an overview of how S. aureus initiates and maintains infection and discuss the main determinants involved. A more in-depth understanding of the function and contribution of S. aureus virulence determinants to S. aureus infection will enable us to develop anti-virulence strategies to counteract the lack of an anti-S. aureus vaccine and the ever-increasing shortage of working antibiotics against this important pathogen.
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Affiliation(s)
- Gordon Y. C. Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Justin S. Bae
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
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39
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Onyedibe KI, Dayal N, Sintim HO. SF 5- and SCF 3-substituted tetrahydroquinoline compounds as potent bactericidal agents against multidrug-resistant persister Gram-positive bacteria. RSC Med Chem 2021; 12:1879-1893. [PMID: 34825185 DOI: 10.1039/d1md00211b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/09/2021] [Indexed: 11/21/2022] Open
Abstract
Bacteria persister cells are immune to most antibiotics and hence compounds that are active against persister bacteria are needed. We screened a chemical library of SF5- and SCF3-substituted tetrahydroquinoline compounds, synthesized via the Povarov reaction, for antibacterial activity and identified active compounds that displayed good activities against many Gram-positive bacteria, including persisters. The most potent of these compounds, HSD1835, inhibited the growth of drug-resistant Gram-positive bacterial pathogens (including clinical strains) at concentrations ranging from 1 μg mL-1 to 4 μg mL-1. Several of the SCF3- and SF5-containing compounds were active against methicillin-resistant Staphylococcus aureus (MRSA) and against the two most fatal strains of vancomycin-resistant Enterococcus (VRE), VRE faecalis and VRE faecium. The compounds showed bactericidal activity against stationary phase persister MRSA in time-kill assays. Mechanistic studies showed that HSD1835 acts by disrupting bacterial membranes. Scanning electron microscopy (SEM) was used to confirm bacterial membrane disruption. Interestingly, in a 30 day serial exposure experiment, MRSA remained susceptible to low-dose HSD1835 whilst resistance to ciprofloxacin and mupirocin emerged by day 10. Analogs of HSD1835, which did not bear the SF5 or SCF3 moieties, were inactive against bacteria. Recent reports (G. A. Naclerio, N. S. Abutaleb, K. I. Onyedibe, M. N. Seleem and H. O. Sintim, RSC Med. Chem. 2020, 11, 102-110 and G. A. Naclerio, N. S. Abutaleb, D. Li, M. N. Seleem and H. O. Sintim, J. Med. Chem. 2020, 63(20), 11934-11944) also demonstrated that adding the SF5 or SCF3 groups to a different scaffold (oxadiazoles) enhanced the antibacterial properties of the compounds, so it appears that these groups are privileged moieties that enhance the antimicrobial activities of compounds.
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Affiliation(s)
- Kenneth I Onyedibe
- Department of Chemistry, Purdue University 560 Oval Drive, West Lafayette Indiana 47907 USA .,Purdue Institute of Inflammation, Immunology, and Infectious Disease West Lafayette IN 47907 USA
| | - Neetu Dayal
- Department of Chemistry, Purdue University 560 Oval Drive, West Lafayette Indiana 47907 USA
| | - Herman O Sintim
- Department of Chemistry, Purdue University 560 Oval Drive, West Lafayette Indiana 47907 USA .,Purdue Institute of Inflammation, Immunology, and Infectious Disease West Lafayette IN 47907 USA.,Center for Drug Discovery, Purdue University 720 Clinic Drive, West Lafayette Indiana 47907 USA
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40
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In-Vitro Cytotoxicity and Clinical Correlates of MRSA Bacteremia. Antimicrob Agents Chemother 2021; 66:e0155921. [PMID: 34748383 DOI: 10.1128/aac.01559-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections are associated with significant morbidity and mortality. MRSA secretes a number of virulence factors and pore-forming toxins that enable tissue invasion. Prior studies have found associations between decreased toxin production and poor outcomes in invasive MRSA infection, particularly in pneumonia. In this retrospective observational cohort study of MRSA bacteremia in adult patients 2007-2015, we examined whether cytotoxicity was associated with 30-day mortality. Isolates were obtained from 776 patients and screened for cytotoxicity in a human HL-60 cell model, antimicrobial susceptibility and spa type, and clinical data were abstracted from charts. We did not find an association between low cytotoxic activity and 30-day mortality in univariate logistic regression analyses. There was a difference in distribution of the genotypes across cytotoxicity phenotypes, with spa-CC008 accounting for a larger proportion of isolates in the high cytotoxicity group. Isolates with a skin and soft tissue primary infective site had a higher median cytotoxicity. There was no association between cytotoxicity and host factors such as age or comorbidity burden. The isolates in our study came from heterogeneous primary sites of infection and were predominantly from spa-CC002 and spa-CC008 lineages, so it is possible that findings in prior studies reflect a different distribution in genotypes and clinical syndromes. Overall, in this large study of cytotoxicity of MRSA bloodstream isolates, we did not find the low cytotoxicity phenotype to be predictive of poor outcomes in MRSA bacteremia.
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Young BC, Wu CH, Charlesworth J, Earle S, Price JR, Gordon NC, Cole K, Dunn L, Liu E, Oakley S, Godwin H, Fung R, Miller R, Knox K, Votintseva A, Quan TP, Tilley R, Scarborough M, Crook DW, Peto TE, Walker AS, Llewelyn MJ, Wilson DJ. Antimicrobial resistance determinants are associated with Staphylococcus aureus bacteraemia and adaptation to the healthcare environment: a bacterial genome-wide association study. Microb Genom 2021; 7:000700. [PMID: 34812717 PMCID: PMC8743558 DOI: 10.1099/mgen.0.000700] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 09/30/2021] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus is a major bacterial pathogen in humans, and a dominant cause of severe bloodstream infections. Globally, antimicrobial resistance (AMR) in S. aureus remains challenging. While human risk factors for infection have been defined, contradictory evidence exists for the role of bacterial genomic variation in S. aureus disease. To investigate the contribution of bacterial lineage and genomic variation to the development of bloodstream infection, we undertook a genome-wide association study comparing bacteria from 1017 individuals with bacteraemia to 984 adults with asymptomatic S. aureus nasal carriage. Within 984 carriage isolates, we also compared healthcare-associated (HA) carriage with community-associated (CA) carriage. All major global lineages were represented in both bacteraemia and carriage, with no evidence for different infection rates. However, kmers tagging trimethoprim resistance-conferring mutation F99Y in dfrB were significantly associated with bacteraemia-vs-carriage (P=10-8.9-10-9.3). Pooling variation within genes, bacteraemia-vs-carriage was associated with the presence of mecA (HMP=10-5.3) as well as the presence of SCCmec (HMP=10-4.4). Among S. aureus carriers, no lineages were associated with HA-vs-CA carriage. However, we found a novel signal of HA-vs-CA carriage in the foldase protein prsA, where kmers representing conserved sequence allele were associated with CA carriage (P=10-7.1-10-19.4), while in gyrA, a ciprofloxacin resistance-conferring mutation, L84S, was associated with HA carriage (P=10-7.2). In an extensive study of S. aureus bacteraemia and nasal carriage in the UK, we found strong evidence that all S. aureus lineages are equally capable of causing bloodstream infection, and of being carried in the healthcare environment. Genomic variation in the foldase protein prsA is a novel genomic marker of healthcare origin in S. aureus but was not associated with bacteraemia. AMR determinants were associated with both bacteraemia and healthcare-associated carriage, suggesting that AMR increases the propensity not only to survive in healthcare environments, but also to cause invasive disease.
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Affiliation(s)
- Bernadette C. Young
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Chieh-Hsi Wu
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Jane Charlesworth
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Sarah Earle
- Big Data Institute, Nuffield Department of Population Health, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Oxford, OX3 7LF, UK
| | - James R. Price
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton BN2 5BE, UK
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9PS, UK
| | - N. Claire Gordon
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Kevin Cole
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton BN2 5BE, UK
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9PS, UK
| | - Laura Dunn
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Elian Liu
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Sarah Oakley
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Heather Godwin
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Rowena Fung
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Ruth Miller
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Kyle Knox
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
| | - Antonina Votintseva
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - T. Phuong Quan
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, UK
- NIHR Health Protection Unit in Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford in partnership with Public Health England, Oxford, UK
| | - Robert Tilley
- Department of Microbiology, University Hospitals Plymouth NHS Trust, Derriford Hospital, Plymouth PL6 8DH, UK
| | - Matthew Scarborough
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Derrick W. Crook
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
- National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, UK
- NIHR Health Protection Unit in Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford in partnership with Public Health England, Oxford, UK
| | - Timothy E. Peto
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Microbiology and Infectious Diseases Department, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
- National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, UK
- NIHR Health Protection Unit in Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford in partnership with Public Health England, Oxford, UK
| | - A. Sarah Walker
- Nuffield Department of Medicine, Experimental Medicine Division, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- National Institute for Health Research, Oxford Biomedical Research Centre, Oxford, UK
- NIHR Health Protection Unit in Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford in partnership with Public Health England, Oxford, UK
| | - Martin J. Llewelyn
- Department of Infectious Diseases and Microbiology, Royal Sussex County Hospital, Brighton BN2 5BE, UK
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9PS, UK
| | - Daniel J. Wilson
- Big Data Institute, Nuffield Department of Population Health, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Old Road Campus, Oxford, OX3 7LF, UK
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RexAB promotes the survival of Staphylococcus aureus exposed to multiple classes of antibiotics. Antimicrob Agents Chemother 2021; 65:e0059421. [PMID: 34310219 PMCID: PMC8448105 DOI: 10.1128/aac.00594-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Antibiotics inhibit essential bacterial processes, resulting in arrest of growth and, in some cases, cell death. Many antibiotics are also reported to trigger endogenous production of reactive oxygen species (ROS), which damage DNA, leading to induction of the mutagenic SOS response associated with the emergence of drug resistance. However, the type of DNA damage that arises and how this triggers the SOS response are largely unclear. We found that several different classes of antibiotic triggered dose-dependent induction of the SOS response in Staphylococcus aureus, indicative of DNA damage, including some bacteriostatic drugs. The SOS response was heterogenous and varied in magnitude between strains and antibiotics. However, in many cases, full induction of the SOS response was dependent upon the RexAB helicase/nuclease complex, which processes DNA double-strand breaks to produce single-stranded DNA and facilitate RecA nucleoprotein filament formation. The importance of RexAB in repair of DNA was confirmed by measuring bacterial survival during antibiotic exposure, with most drugs having significantly greater bactericidal activity against rexB mutants than against wild-type strains. For some, but not all, antibiotics there was no difference in bactericidal activity between wild type and rexB mutant under anaerobic conditions, indicative of a role for reactive oxygen species in mediating DNA damage. Taken together, this work confirms previous observations that several classes of antibiotics cause DNA damage in S. aureus and extends them by showing that processing of DNA double-strand breaks by RexAB is a major trigger of the mutagenic SOS response and promotes bacterial survival.
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Chung H, Kim E, Yang E, Lee YW, Park JH, Bae S, Jung J, Kim MJ, Chong YP, Kim SH, Lee SO, Choi SH, Kim YS. C-reactive protein predicts persistent bacteremia caused by community-acquired methicillin-resistant Staphylococcus aureus strain. Eur J Clin Microbiol Infect Dis 2021; 40:2497-2504. [PMID: 34245388 DOI: 10.1007/s10096-021-04303-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/28/2021] [Indexed: 10/20/2022]
Abstract
There is limited data on persistent bacteremia (PB) caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Here, we aimed to investigate the clinical and microbiological characteristics of PB caused by the major CA-MRSA strain in Korea (ST72-SCCmecIV). All adult patients with S. aureus bacteremia were prospectively investigated from August 2008 to December 2018. Patients with ST72 MRSA bacteremia were included in the study. Patients were stratified into the PB group (defined as positive blood cultures for ≥ 3 days) and short bacteremia (SB) group. A total of 291 patients were included, comprising 115 (39.5%) with PB and 176 (60.5%) with SB. Although the 30-day mortality did not differ between PB and SB, recurrent bacteremia within 12 weeks was significantly more common in PB (8.7% vs 1.7%; P = 0.01). Multivariate analysis showed risk factors of PB were liver cirrhosis (adjusted odds ratio [aOR], 3.27; 95% confidence interval [CI], 1.50-7.12), infective endocarditis (aOR, 7.13; 95% CI, 1.37-37.12), bone and joint infections (aOR, 3.76; 95% CI, 1.62-8.77), C-reactive protein ≥ 10 mg/dL (aOR, 2.20; 95% CI, 1.22-3.95), metastatic infection (aOR, 7.35; 95% CI, 3.53-15.29), and agr dysfunction (aOR, 2.47; 95% CI, 1.05-5.81). PB occurred in approximately 40% of bacteremia caused by ST72 MRSA with a significantly higher recurrence rate. Patients with risk factors of PB, including liver cirrhosis, high initial CRP, infective endocarditis, or bone and joint infections, might require early aggressive treatment.
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Affiliation(s)
- Hyemin Chung
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Eunsil Kim
- Center for Antimicrobial Resistance and Microbial Genetics, University of Ulsan, 88 Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, Republic of Korea
| | - Eunmi Yang
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yun Woo Lee
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Joung Ha Park
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Seongman Bae
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jiwon Jung
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Min Jae Kim
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yong Pil Chong
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sung-Han Kim
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-Oh Lee
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-Ho Choi
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yang Soo Kim
- Division of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. .,Center for Antimicrobial Resistance and Microbial Genetics, University of Ulsan, 88 Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.
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Derakhshan S, Navidinia M, Haghi F. Antibiotic susceptibility of human-associated Staphylococcus aureus and its relation to agr typing, virulence genes, and biofilm formation. BMC Infect Dis 2021; 21:627. [PMID: 34210263 PMCID: PMC8247160 DOI: 10.1186/s12879-021-06307-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/10/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Carriage of virulence factors confers some evolutionary benefit to bacteria, which favors the resistant strains. We aimed to analyze whether antibiotic susceptibility of Staphylococcus aureus strains is affected by agr typing, biofilm formation ability, and virulence profiles. METHODS A total of 123 S. aureus clinical isolates were subjected to antimicrobial susceptibility testing by disk diffusion method, biofilm formation by microtiter plate method, as well as polymerase chain reaction screening to identify virulence genes and the accessory gene regulator (agr) types I-IV. A P value < 0.05 was considered significant. RESULTS The most prevalent virulence gene was staphyloxanthin crtN, followed by hemolysin genes, capsular cap8H, toxic shock toxin tst, and enterotoxin sea, respectively. Resistant isolates were more commonly found in the agr-negative group than in the agr-positive group. Isolates of agr type III were more virulent than agr I isolates. Strong biofilm producers showed more antibiotic susceptibility and carried more virulence genes than non-strong biofilm producers. Associations were found between the presence of virulence genes and susceptibility to antibiotics. Carriage of the virulence genes and agr was higher in the inpatients; while, resistance and strong biofilms were more prevalent in the outpatients. CONCLUSION These findings indicated the presence of several virulence factors, biofilm production capacity, agr types and resistance to antibiotics in clinical S. aureus isolates. Considering the importance of S. aureus for human medicine, an understanding of virulence and resistance relationships would help to reduce the impact of S. aureus infections.
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Affiliation(s)
- Safoura Derakhshan
- Liver and Digestive Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
| | - Masoumeh Navidinia
- School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fakhri Haghi
- Department of Microbiology and Immunology, Faculty of Medical Sciences, Zanjan University of Medical Sciences, Zanjan, Iran
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Rowe SE, Beam JE, Conlon BP. Recalcitrant Staphylococcus aureus Infections: Obstacles and Solutions. Infect Immun 2021; 89:e00694-20. [PMID: 33526569 PMCID: PMC8090968 DOI: 10.1128/iai.00694-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Antibiotic treatment failure of Staphylococcus aureus infections is very common. In addition to genetically encoded mechanisms of antibiotic resistance, numerous additional factors limit the efficacy of antibiotics in vivo Identifying and removing the barriers to antibiotic efficacy are of major importance, as even if new antibiotics become available, they will likely face the same barriers to efficacy as their predecessors. One major obstacle to antibiotic efficacy is the proficiency of S. aureus to enter a physiological state that is incompatible with antibiotic killing. Multiple pathways leading to antibiotic tolerance and the formation of tolerant subpopulations called persister cells have been described for S. aureus Additionally, S. aureus is a versatile pathogen that can infect numerous tissues and invade a variety of cell types, of which some are poorly penetrable to antibiotics. It is therefore unlikely that there will be a single solution to the problem of recalcitrant S. aureus infection. Instead, specific approaches may be required for targeting tolerant cells within different niches, be it through direct targeting of persister cells, sensitization of persisters to conventional antibiotics, improved penetration of antibiotics to particular niches, or any combination thereof. Here, we examine two well-described reservoirs of antibiotic-tolerant S. aureus, the biofilm and the macrophage, the barriers these environments present to antibiotic efficacy, and potential solutions to the problem.
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Affiliation(s)
- Sarah E Rowe
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jenna E Beam
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Brian P Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Chang YL, Rossetti M, Gjertson DW, Rubbi L, Thompson M, Montoya DJ, Morselli M, Ruffin F, Hoffmann A, Pellegrini M, Fowler VG, Yeaman MR, Reed EF. Human DNA methylation signatures differentiate persistent from resolving MRSA bacteremia. Proc Natl Acad Sci U S A 2021; 118:e2000663118. [PMID: 33649198 PMCID: PMC7958259 DOI: 10.1073/pnas.2000663118] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 12/21/2020] [Indexed: 12/26/2022] Open
Abstract
Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is life threatening and occurs in up to 30% of MRSA bacteremia cases despite appropriate antimicrobial therapy. Isolates of MRSA that cause antibiotic-persistent methicillin-resistant S. aureus bacteremia (APMB) typically have in vitro antibiotic susceptibilities equivalent to those causing antibiotic-resolving methicillin-resistant S. aureus bacteremia (ARMB). Thus, persistence reflects host-pathogen interactions occurring uniquely in context of antibiotic therapy in vivo. However, host factors and mechanisms involved in APMB remain unclear. We compared DNA methylomes in circulating immune cells from patients experiencing APMB vs. ARMB. Overall, methylation signatures diverged in the distinct patient cohorts. Differentially methylated sites intensified proximate to transcription factor binding sites, primarily in enhancer regions. In APMB patients, significant hypomethylation was observed in binding sites for CCAAT enhancer binding protein-β (C/EBPβ) and signal transducer/activator of transcription 1 (STAT1). In contrast, hypomethylation in ARMB patients localized to glucocorticoid receptor and histone acetyltransferase p300 binding sites. These distinct methylation signatures were enriched in neutrophils and achieved a mean area under the curve of 0.85 when used to predict APMB using a classification model. These findings validated by targeted bisulfite sequencing (TBS-seq) differentiate epigenotypes in patients experiencing APMB vs. ARMB and suggest a risk stratification strategy for antibiotic persistence in patients treated for MRSA bacteremia.
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Affiliation(s)
- Yu-Ling Chang
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Maura Rossetti
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - David W Gjertson
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, CA 90095
| | - Liudmilla Rubbi
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095
| | - Michael Thompson
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095
| | | | - Marco Morselli
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095
| | - Felicia Ruffin
- Division of Infectious Diseases, Duke University, Durham, NC 27710
| | - Alexander Hoffmann
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, CA 90095
| | - Matteo Pellegrini
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095
| | - Vance G Fowler
- Division of Infectious Diseases, Duke University, Durham, NC 27710
| | - Michael R Yeaman
- Division of Molecular Medicine, Harbor-University of California, Los Angeles Medical Center, Torrance, CA 90502
- Division of Infectious Diseases, Harbor-University of California, Los Angeles Medical Center, Torrance, CA 90502
- Lundquist Institute for Biomedical Innovation at Harbor-University of California, Los Angeles Medical Center, Torrance, CA 90502
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Elaine F Reed
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095;
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Cheung GYC, Bae JS, Liu R, Hunt RL, Zheng Y, Otto M. Bacterial virulence plays a crucial role in MRSA sepsis. PLoS Pathog 2021; 17:e1009369. [PMID: 33630954 PMCID: PMC7942999 DOI: 10.1371/journal.ppat.1009369] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 03/09/2021] [Accepted: 02/10/2021] [Indexed: 12/29/2022] Open
Abstract
Bacterial sepsis is a major global cause of death. However, the pathophysiology of sepsis has remained poorly understood. In industrialized nations, Staphylococcus aureus represents the pathogen most commonly associated with mortality due to sepsis. Because of the alarming spread of antibiotic resistance, anti-virulence strategies are often proposed to treat staphylococcal sepsis. However, we do not yet completely understand if and how bacterial virulence contributes to sepsis, which is vital for a thorough assessment of such strategies. We here examined the role of virulence and quorum-sensing regulation in mouse and rabbit models of sepsis caused by methicillin-resistant S. aureus (MRSA). We determined that leukopenia was a predictor of disease outcome during an early critical stage of sepsis. Furthermore, in device-associated infection as the most frequent type of staphylococcal blood infection, quorum-sensing deficiency resulted in significantly higher mortality. Our findings give important guidance regarding anti-virulence drug development strategies for the treatment of staphylococcal sepsis. Moreover, they considerably add to our understanding of how bacterial sepsis develops by revealing a critical early stage of infection during which the battle between bacteria and leukocytes determines sepsis outcome. While sepsis has traditionally been attributed mainly to host factors, our study highlights a key role of the invading pathogen and its virulence mechanisms.
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Affiliation(s)
- Gordon Y. C. Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Justin S. Bae
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Rachelle L. Hunt
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yue Zheng
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Distinct clonal lineages and within-host diversification shape invasive Staphylococcus epidermidis populations. PLoS Pathog 2021; 17:e1009304. [PMID: 33544760 PMCID: PMC7891712 DOI: 10.1371/journal.ppat.1009304] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/18/2021] [Accepted: 01/11/2021] [Indexed: 12/15/2022] Open
Abstract
S. epidermidis is a substantial component of the human skin microbiota, but also one of the major causes of nosocomial infection in the context of implanted medical devices. We here aimed to advance the understanding of S. epidermidis genotypes and phenotypes conducive to infection establishment. Furthermore, we investigate the adaptation of individual clonal lines to the infection lifestyle based on the detailed analysis of individual S. epidermidis populations of 23 patients suffering from prosthetic joint infection. Analysis of invasive and colonizing S. epidermidis provided evidence that invasive S. epidermidis are characterized by infection-supporting phenotypes (e.g. increased biofilm formation, growth in nutrient poor media and antibiotic resistance), as well as specific genetic traits. The discriminating gene loci were almost exclusively assigned to the mobilome. Here, in addition to IS256 and SCCmec, chromosomally integrated phages was identified for the first time. These phenotypic and genotypic features were more likely present in isolates belonging to sequence type (ST) 2. By comparing seven patient-matched nasal and invasive S. epidermidis isolates belonging to identical genetic lineages, infection-associated phenotypic and genotypic changes were documented. Besides increased biofilm production, the invasive isolates were characterized by better growth in nutrient-poor media and reduced hemolysis. By examining several colonies grown in parallel from each infection, evidence for genetic within-host population heterogeneity was obtained. Importantly, subpopulations carrying IS insertions in agrC, mutations in the acetate kinase (AckA) and deletions in the SCCmec element emerged in several infections. In summary, these results shed light on the multifactorial processes of infection adaptation and demonstrate how S. epidermidis is able to flexibly repurpose and edit factors important for colonization to facilitate survival in hostile infection environments. S. epidermidis is a substantial component of the human skin microbiota, but also a major cause of nosocomial infections related to implanted medical devices. While phenotypic and genotypic determinants supporting invasion were identified, none appears to be necessary. By analysis of S. epidermidis from prosthetic joint infections, we here show that adaptive events are of importance during the transition from commensalism to infection. Adaptation to the infectious lifestyle is characterised by the development of intra-clonal heterogeneity, increased biofilm formation and enhanced growth in iron-free and nutrient-poor media, as well as reduced production of hemolysins. Importantly, during infection subpopulations emerge that carry mutations in a number of genes, most importantly the acetate kinase (ackA) and the β-subunit of the RNA polymerase (rpoB), have deleted larger chromosomal fragments (e.g. within the SCCmec element) or IS insertions in AgrC, a component of the master quorum sensing system in S. epidermidis. These results shed light on the multifactorial processes of infection adaptation and demonstrate how S. epidermidis is able to flexibly repurpose and edit factors important for colonization to facilitate survival under hostile infection conditions. While mobilome associated factors are important for S. epidermidis invasive potential, the species possesses a multi-layered and complex ability for adaptation to hostile environments, supporting the progression to chronic implant-associated infections.
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Lee SO, Lee S, Lee JE, Song KH, Kang CK, Wi YM, San-Juan R, López-Cortés LE, Lacoma A, Prat C, Jang HC, Kim ES, Kim HB, Lee SH. Dysfunctional accessory gene regulator (agr) as a prognostic factor in invasive Staphylococcus aureus infection: a systematic review and meta-analysis. Sci Rep 2020; 10:20697. [PMID: 33244173 PMCID: PMC7691521 DOI: 10.1038/s41598-020-77729-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
The accessory gene regulator (agr) locus of Staphylococcus aureus is a quorum-sensing virulence regulator. Although there are many studies concerning the effect of dysfunctional agr on the outcomes of S. aureus infection, there is no systematic review to date. We systematically searched for clinical studies reporting outcomes of invasive S. aureus infections and the proportion of dysfunctional agr among their causative strains, and we performed a meta-analysis to obtain estimates of the odds of outcomes of invasive S. aureus infection with dysfunctional versus functional agr. Of 289 articles identified by our research strategy, 20 studies were meta-analysed for crude analysis of the impact of dysfunctional agr on outcomes of invasive S. aureus infection. Dysfunctional agr was generally associated with unfavourable outcomes (OR 1.32, 95% CI 1.05–1.66), and the impact of dysfunctional agr on outcome was more prominent in invasive methicillin-resistant S. aureus (MRSA) infections (OR 1.54, CI 1.20–1.97). Nine studies were meta-analysed for the impact of dysfunctional agr on the 30-day mortality of invasive S. aureus infection. Invasive MRSA infection with dysfunctional agr exhibited higher 30-day mortality (OR 1.40, CI 1.03–1.90) than that with functional agr. On the other hand, invasive MSSA infection with dysfunctional agr exhibited lower 30-day mortality (OR 0.51, CI 0.27–0.95). In the post hoc subgroup analysis by the site of MRSA infection, dysfunctional agr was associated with higher 30-day mortality in MRSA pneumonia (OR 2.48, CI 1.17–5.25). The effect of dysfunctional agr on the outcome of invasive S. aureus infection may vary depending on various conditions, such as oxacillin susceptibility and the site of infection. Dysfunctional agr was generally associated with unfavourable clinical outcomes and its effect was prominent in MRSA and pneumonia. Dysfunctional agr may be applicable for outcome prediction in cases of invasive MRSA infection with hardly eradicable foci such as pneumonia.
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Affiliation(s)
- Soon Ok Lee
- Department of Internal Medicine, Pusan National University School of Medicine and Medical Research Institute, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan, 49241, Republic of Korea
| | - Shinwon Lee
- Department of Internal Medicine, Pusan National University School of Medicine and Medical Research Institute, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan, 49241, Republic of Korea.
| | - Jeong Eun Lee
- Department of Internal Medicine, Pusan National University School of Medicine and Medical Research Institute, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan, 49241, Republic of Korea
| | - Kyoung-Ho Song
- Department of Internal Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Chang Kyung Kang
- Department of Internal Medicine, Seoul National University College of Medicine and Seoul National University Hospital, Seoul, Republic of Korea
| | - Yu Mi Wi
- Division of Infectious Diseases, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea
| | - Rafael San-Juan
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córdoba, s/n, Madrid, Spain
| | - Luis E López-Cortés
- Unidad Clínica de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena/Departamento de Medicina, Universidad de Sevilla/Instituto de Biomedicina de Sevilla, Sevilla, Spain
| | - Alicia Lacoma
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Institut d' Investigació Germans Trias i Pujol, CIBER Enfermedades Respiratorias (CIBERES), Universitat Autònoma de Barcelona, Badalona, Spain
| | - Cristina Prat
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Institut d' Investigació Germans Trias i Pujol, CIBER Enfermedades Respiratorias (CIBERES), Universitat Autònoma de Barcelona, Badalona, Spain.,Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Hee-Chang Jang
- Department of Infectious Diseases, Chonnam National University Medical School, Gwang-ju, Republic of Korea
| | - Eu Suk Kim
- Department of Internal Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Hong Bin Kim
- Department of Internal Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Sun Hee Lee
- Department of Internal Medicine, Pusan National University School of Medicine and Medical Research Institute, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan, 49241, Republic of Korea
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Huang Q, Xie Y, Yang Z, Cheng D, He L, Wang H, Liu Q, Li M. The cytoplasmic loops of AgrC contribute to the quorum-sensing activity of Staphylococcus aureus. J Microbiol 2020; 59:92-100. [PMID: 33201435 DOI: 10.1007/s12275-021-0274-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/22/2020] [Accepted: 09/25/2020] [Indexed: 11/29/2022]
Abstract
In Staphylococcus aureus, the accessory gene regulator (agr) quorum-sensing system is thought to play an important role in biofilm formation. The histidine kinase AgrC is one of the agr system components and activated by the self-generated auto-inducing peptide (AIP), which is released continuously into the extracellular environment during bacterial growth. The extracellular loops (Extra-loops) of AgrC are crucial for AIP binding. Here, we reported that the cytoplasmic loops (Cyto-loops) of AgrC are also involved in Agr activity. We identified S. aureus ST398 clinical isolates containing a naturally occurring single amino acid substitution (lysine to isoleucine) at position 73 of an AgrC Cyto-loop that exhibited significantly stronger biofilm formation and decreased Agr activity compared to the wild-type strain. A constructed strain containing the K73I point mutation in AgrC Cyto-loop continued to show a growth dependent induction of the agr system, although the growth dependent induction was delayed by about 6 h compared to the wild-type. In addition, a series of strains containing deletion mutants of the AgrC Cyto- and Extra-loops were constructed and revealed that the removal of the two Cyto-loops and Extra-loops 2 and 3 totally abolished the Agr activity and the growth-dependence on the agr system induction. Remarkably, the Extra-loop 1 deletion did not affect the Agr activity. In conclusion, the AgrC Cyto-loops play a crucial role in the S. aureus quorum-sensing activity.
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Affiliation(s)
- Qian Huang
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China
| | - Yihui Xie
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China
| | - Ziyu Yang
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China
| | - Danhong Cheng
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China
| | - Lei He
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China
| | - Hua Wang
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China
| | - Qian Liu
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China.
| | - Min Li
- Department of Laboratory Medicine, RenJi Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, P. R. China.
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