Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Sep 16, 2021; 9(26): 7693-7703
Published online Sep 16, 2021. doi: 10.12998/wjcc.v9.i26.7693
Clinical metagenomic sequencing for rapid diagnosis of pneumonia and meningitis caused by Chlamydia psittaci
Xiao-Wei Yin, Zheng-Dao Mao, Qian Zhang, Qiu-Xiang Ou, Jia Liu, Yang Shao, Zhi-Guang Liu
Xiao-Wei Yin, Zheng-Dao Mao, Qian Zhang, Zhi-Guang Liu, Department of Respiratory and Critical Care Medicine, Changzhou Second People’s Hospital Affiliated to Nanjing Medical University, Changzhou 213164, Jiangsu Province, China
Qiu-Xiang Ou, Yang Shao, Research & Development, Nanjing Geneseeq Technology Inc., Nanjing 210032, Jiangsu Province, China
Jia Liu, Research & Development, Dinfectome Inc., Nanjing 213164, Jiangsu Province, China
Yang Shao, School of Public Health, Nanjing Medical University, Nanjing 213164, Jiangsu Province, China
Author contributions: Yin XW contributed to the study concept and design and drafting of the manuscript; Mao ZD and Zhang Q contributed to the acquisition of data; Ou QX and Liu J contributed to the interpretation of data and drafting of the manuscript; Shao Y contributed to critical revision of the manuscript; Liu ZG supervised the study; all authors have read and approved the final manuscript.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of Changzhou Second People’s Hospital affiliated to Nanjing Medical University, China (approval No. 2020KY268-01).
Informed consent statement: All study participants provided informed consent prior to sample collection according to the institutional guidelines and gave permissions to the use of their clinical data and accompanying images.
Conflict-of-interest statement: Ou QX and Shao Y are employees of Nanjing Geneseeq Technology Inc; Liu J is an employee of Dinfectome Inc. The remaining authors have nothing to disclose.
Data sharing statement: The authors confirm that the data supporting the findings of this study are available within the article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Zhi-Guang Liu, MD, Doctor, Department of Respiratory and Critical Care Medicine, Changzhou Second People’s Hospital Affiliated to Nanjing Medical University, No. 68 Gehu Road, Wujin District, Changzhou 213164, Jiangsu Province, China. 545485079@qq.com
Received: February 18, 2021
Peer-review started: February 18, 2021
First decision: April 13, 2021
Revised: April 15, 2021
Accepted: July 2, 2021
Article in press: July 2, 2021
Published online: September 16, 2021
Processing time: 197 Days and 4.8 Hours
Abstract
BACKGROUND

Chlamydia psittaci (C. psittaci) is a gram-negative intracellular parasitic pathogenic bacterium that can infect avian and mammalian hosts, including humans. The detection of C. psittaci infections typically relies on traditional antigen-based immunoassays or serological testing that often lack sensitivity and/or specificity. Metagenomic next generation sequencing (mNGS) is an emerging tool for diagnosis.

AIM

To demonstrate that mNGS represents a valuable tool for rapid, sensitive, and accurate pathogen detection including C. psittaci infections.

METHODS

Four cases of psittacosis pneumonia and one case of pediatric psittacosis meningitis were diagnosed between December 2019 and May 2020 using mNGS at Changzhou Second People’s Hospital affiliated to Nanjing Medical University. Patients’ clinical characteristics, manifestations, and treatment histories were retrospectively evaluated.

RESULTS

All five patients had a history of exposure to wild (psittacine or other birds) or domesticated birds (chickens). All patients had a high fever (> 39℃) and three of them (60%) experienced organ insufficiency during the disease. The laboratory data showed normal to slightly increased leucocyte and neutrophil counts, and elevated procalcitonin levels in all five cases, and very high C-reactive protein levels in psittacosis pneumonia patients. mNGS identified a potential pathogen, C. psittaci, in patients’ bronchoalveolar lavage fluid or cerebrospinal fluid. Computed tomography revealed lung air-space consolidation, pleural thickening, and effusion fluid buildup in psittacosis pneumonia cases, and an arachnoid cyst in the right temporal lobe of the pediatric psittacosis meningitis patient. All patients experienced complete recovery following the administration of targeted anti-chlamydia therapy.

CONCLUSION

This study not only demonstrated that mNGS represents a valuable tool for rapid, sensitive, and accurate pathogen detection, but also raised public health concerns over C. psittaci infections.

Keywords: Chlamydia psittaci; Pneumonia; Meningitis; Metagenomic next generation sequencing; Etiology; Infectious disease

Core Tip: Detection of Chlamydia psittaci (C. psittaci) infections relies on traditional antigen-based immunoassays or serological testing that often lack sensitivity and/or specificity. Our data not only reinforce that metagenomic next generation sequencing represents a valuable tool for rapid, sensitive, and accurate pathogen detection, including the identification of C. psittaci, but also raise public health concerns over C. psittaci infections.