|
1
|
The Phylogeny and Biological Function of Gastric Juice-Microbiological Consequences of Removing Gastric Acid. Int J Mol Sci 2019; 20:ijms20236031. [PMID: 31795477 PMCID: PMC6928904 DOI: 10.3390/ijms20236031] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 12/15/2022] Open
Abstract
Gastric juice is a unique combination of hydrochloric acid (HCl), lipase, and pepsin. Acidic gastric juice is found in all vertebrates, and its main function is to inactivate microorganisms. The phylogenetic preservation of this energy-consuming and, at times, hazardous function (acid-related diseases) reflects its biological importance. Proton pump inhibitors (PPIs) are one of the most widely used drugs in the world. Due to the reduced prevalence of Helicobacter pylori infection as well as the increased use of inhibitors of gastric acid secretion, the latter has become the most important cause of gastric hypoacidity. In the present manuscript, we review the microbiological consequences of removing gastric acidity. The resulting susceptibility to infections has not been studied extensively, and focus has mainly been restricted to bacterial and parasitic agents only. The strongest evidence concerning the relationship between hypochlorhydria and predisposition to infections relates to bacterial infections affecting the gastrointestinal tract. However, several other clinical settings with increased susceptibility to infections due to inhibited gastric acidity are discussed. We also discuss the impact of hypochlorhydria on the gut microbiome.
Collapse
|
|
2
|
Abstract
This narrative review summarises the benefits, risks and appropriate use of acid-suppressing drugs (ASDs), proton pump inhibitors and histamine-2 receptor antagonists, advocating a rationale balanced and individualised approach aimed to minimise any serious adverse consequences. It focuses on current controversies on the potential of ASDs to contribute to infections-bacterial, parasitic, fungal, protozoan and viral, particularly in the elderly, comprehensively and critically discusses the growing body of observational literature linking ASD use to a variety of enteric, respiratory, skin and systemic infectious diseases and complications (Clostridium difficile diarrhoea, pneumonia, spontaneous bacterial peritonitis, septicaemia and other). The proposed pathogenic mechanisms of ASD-associated infections (related and unrelated to the inhibition of gastric acid secretion, alterations of the gut microbiome and immunity), and drug-drug interactions are also described. Both probiotics use and correcting vitamin D status may have a significant protective effect decreasing the incidence of ASD-associated infections, especially in the elderly. Despite the limitations of the existing data, the importance of individualised therapy and caution in long-term ASD use considering the balance of benefits and potential harms, factors that may predispose to and actions that may prevent/attenuate adverse effects is evident. A six-step practical algorithm for ASD therapy based on the best available evidence is presented.
Collapse
Affiliation(s)
- Leon Fisher
- Frankston Hospital, Peninsula Health, Melbourne, Australia.
| | - Alexander Fisher
- The Canberra Hospital, ACT Health, Canberra, Australia
- Australian National University Medical School, Canberra, Australia
| |
Collapse
|
|
3
|
Reuland EA, Al Naiemi N, Kaiser AM, Heck M, Kluytmans JAJW, Savelkoul PHM, Elders PJM, Vandenbroucke-Grauls CMJE. Prevalence and risk factors for carriage of ESBL-producing Enterobacteriaceae in Amsterdam. J Antimicrob Chemother 2016; 71:1076-82. [PMID: 26755493 PMCID: PMC4790620 DOI: 10.1093/jac/dkv441] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/19/2015] [Indexed: 01/28/2023] Open
Abstract
Objectives The objectives of this study were to determine the prevalence of carriage of ESBL-producing Enterobacteriaceae (ESBL-E) in a representative sample of the general adult Dutch community, to identify risk factors and to gain understanding of the epidemiology of these resistant strains. Methods Adults enrolled in five general practices in Amsterdam were approached by postal mail and asked to fill in a questionnaire and to collect a faecal sample. Samples were analysed for the presence of ESBL-E. ESBL genes were characterized by PCR and sequencing. Strains were typed using MLST and amplified fragment length polymorphism (AFLP) and plasmids were identified by PCR-based replicon typing. Risk factors for carriage were investigated by multivariate analysis. Results ESBL-E were found in 145/1695 (8.6%) samples; 91% were Escherichia coli. Most ESBL genes were of the CTX-M group (blaCTX-M-1 and blaCTX-M-15). MLST ST131 was predominant and mainly associated with CTX-M-15-producing E. coli. One isolate with reduced susceptibility to ertapenem produced OXA-48. In multivariate analyses, use of antimicrobial agents, use of antacids and travel to Africa, Asia and Northern America were associated with carriage of ESBL-E, in particular strains with blaCTX-M-14/15. Conclusions This study showed a high prevalence of ESBL-E carriage in the general Dutch community. Also, outside hospitals, the use of antibiotics was a risk factor; interestingly, use of antacids increased the risk of carriage. A major risk factor in the general population was travel to countries outside Europe, in particular to Asia, Africa and Northern America.
Collapse
Affiliation(s)
- E A Reuland
- Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands
| | - N Al Naiemi
- Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands Laboratory for Medical Microbiology and Public Health, Hengelo, The Netherlands Medical Microbiology and Infection Control, Ziekenhuisgroep Twente, Almelo, The Netherlands
| | - A M Kaiser
- Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands
| | - M Heck
- Center for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - J A J W Kluytmans
- Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands Department of Medical Microbiology and Infection Control, Amphia Hospital, Breda, The Netherlands Department of Medical Microbiology, St Elisabeth Hospital, Tilburg, The Netherlands
| | - P H M Savelkoul
- Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands
| | - P J M Elders
- EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
| | | |
Collapse
|
|
4
|
Franceschi F, Tortora A, Di Rienzo T, D’Angelo G, Ianiro G, Scaldaferri F, Gerardi V, Tesori V, Lopetuso LR, Gasbarrini A. Role of Helicobacter pylori infection on nutrition and metabolism. World J Gastroenterol 2014; 20:12809-12817. [PMID: 25278679 PMCID: PMC4177464 DOI: 10.3748/wjg.v20.i36.12809] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/12/2014] [Accepted: 05/26/2014] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) is a gram-negative pathogen that is widespread all over the world, infecting more than 50% of the world’s population. It is etiologically associated with non-atrophic and atrophic gastritis, peptic ulcer and shows a deep association with primary gastric B-cell lymphoma and gastric adenocarcinoma. Recently, the medical research focused on the modification of the gastric environment induced by H. pylori infection, possibly affecting the absorption of nutrients and drugs as well as the production of hormones strongly implicated in the regulation of appetite and growth. Interestingly, the absorption of iron and vitamin B12 is impaired by H. pylori infection, while infected subjects have lower basal and fasting serum levels of ghrelin and higher concentration of leptin compared to controls. Since leptin is an anorexigenic hormone, and ghrelin stimulates powerfully the release of growth hormone in humans, H. pylori infection may finally induce growth retardation if acquired very early in the childhood and in malnourished children. This review is focused on the nutritional effects of H. pylori infection, such as the reduced bioavailability or the malabsorbption of essential nutrients, and of gastrointestinal hormones, as well as on the relationship between H. pylori and the metabolic syndrome.
Collapse
|
|
5
|
Bias TE, Davanos E, Rahman SM, Venugopalan V. Impact of Gastric Acidity on the Acquisition of Cholera Post Gastric Bypass. Bariatr Surg Pract Patient Care 2013. [DOI: 10.1089/bari.2013.9977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Tiffany E. Bias
- Department of Pharmacy, Hahnemann University Hospital, Philadelphia, Pennsylvania
| | - Evangelia Davanos
- Department of Clinical Pharmacotherapy, The Brooklyn Hospital Center, Brooklyn, New York
| | - Shafiqur M. Rahman
- Division of Infectious Diseases, The Brooklyn Hospital Center, Brooklyn, New York
| | - Veena Venugopalan
- Department of Clinical Pharmacotherapy, The Brooklyn Hospital Center, Brooklyn, New York
| |
Collapse
|
|
6
|
Smith GW, Ahmed AF, Constable PD. Effect of orally administered electrolyte solution formulation on abomasal luminal pH and emptying rate in dairy calves. J Am Vet Med Assoc 2013; 241:1075-82. [PMID: 23039985 DOI: 10.2460/javma.241.8.1075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the effects of 3 commercially available, orally administered electrolyte solutions (OAEs) on abomasal luminal pH and emptying rate in dairy calves, compared with the effect of orally administered milk replacer. DESIGN Randomized crossover study. ANIMALS 6 male dairy calves (age, 12 to 31 days). PROCEDURES Calves were surgically instrumented with an abomasal cannula and were administered 4 treatments in randomized order: all-milk protein milk replacer, high-glucose high-bicarbonate OAE, high-glucose high-bicarbonate OAE containing glycine, and low-glucose OAE containing acetate and propionate. Abomasal luminal pH was measured with a miniature glass pH electrode prior to treatment administration and every second afterward for 24 hours. RESULTS Feeding of orally administered milk replacer resulted in a rapid increase in mean abomasal luminal pH from 1.3 to 5.8, followed by a gradual decrease to preprandial values by 8 hours afterward (mean 24-hour pH, 3.2). High-glucose high-bicarbonate OAEs caused a large and sustained increase from 1.3 to 7.5 (mean 24-hour pH, 4.1 for the solution without glycine and 3.5 for the solution with glycine). In contrast, feeding of the acetate-containing OAE was followed by only a mild and transient increase (mean 24-hour pH, 2.1); luminal pH returned to preprandial values by 3 hours after ingestion. CONCLUSIONS AND CLINICAL RELEVANCE Ingestion of a bicarbonate-containing OAE resulted in sustained abomasal alkalinization in dairy calves. Because persistently high abomasal luminal pH may facilitate growth of enteropathogenic bacteria, administration of OAEs containing a high bicarbonate concentration (> 70mM) is not recommended for calves with diarrhea.
Collapse
Affiliation(s)
- Geof W Smith
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
| | | | | |
Collapse
|
|
7
|
|
|
8
|
Abstract
Salmonella enterica is a genetically broad species harboring isolates that display considerable antigenic heterogeneity and significant differences in virulence potential. Salmonella generally exhibit an invasive potential and they can survive for extended periods within cells of the immune system. They cause acute or chronic infections that can be local (e.g. gastroenteritis) or systemic (e.g. typhoid). In vivo Salmonella infections are complex with multiple arms of the immune system being engaged. Both humoral and cellular responses can be detected and characterized, but full protective immunity is not always induced, even following natural infection. The murine model has proven to be a fertile ground for exploring immune mechanisms and observations in the mouse have often, although not always, correlated with those in other infectable species, including humans. Host genetic studies have identified a number of mammalian genes that are central to controlling infection, operating both in innate and acquired immune pathways. Vaccines, both oral and parenteral, are available or under development, and these have been used with some success to explore immunity in both model systems and clinically in humans.
Collapse
Affiliation(s)
- Gordon Dougan
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge, UK.
| | | | | | | |
Collapse
|
|
9
|
Mossel D, Pflug IJ. Occurrence, prevention, and monitoring of microbial quality loss of foods and dairy products. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/10643387509381624] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
|
10
|
Crum-Cianflone NF. Salmonellosis and the gastrointestinal tract: more than just peanut butter. Curr Gastroenterol Rep 2008; 10:424-31. [PMID: 18627657 PMCID: PMC2753534 DOI: 10.1007/s11894-008-0079-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Nontyphoidal salmonellosis is the leading cause of foodborne illness in the United States, causing about 1.4 million infections annually. Most cases of salmonellosis are due to ingestion of contaminated food items such as eggs, dairy products, and meats, but almost any foodstuff can be implicated, including peanut butter, as seen during a recent outbreak of more than 600 Salmonella infections. Although outbreaks often gain national media attention, the majority of nontyphoidal Salmonella infections in the United States occur sporadically. Risk factors for salmonellosis include gastric hypoacidity, recent use of antibiotics, extremes of age, and immunosuppressive conditions. Clinical manifestations of the infection most commonly involve self-limited gastroenteritis, but bacteremia and endovascular and localized infections may occur. Most cases of gastrointestinal involvement are self-limited, and antibiotic therapy is reserved for persons at risk for complicated disease. Preventive strategies by both industry and consumers are advocated to further reduce the occurrence of nontyphoidal salmonellosis.
Collapse
Affiliation(s)
- Nancy F Crum-Cianflone
- Clinical Investigation Department (KCA), Naval Medical Center San Diego, 34800 Bob Wilson Drive, Suite 5, San Diego, CA 92134-1005, USA.
| |
Collapse
|
|
11
|
|
|
12
|
Gordon MA. Salmonella infections in immunocompromised adults. J Infect 2008; 56:413-22. [PMID: 18474400 DOI: 10.1016/j.jinf.2008.03.012] [Citation(s) in RCA: 305] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 03/25/2008] [Accepted: 03/31/2008] [Indexed: 12/11/2022]
Abstract
Clinical syndromes caused by Salmonella infection in humans are divided into typhoid fever, caused by Salmonella typhi and Salmonella paratyphi, and a range of clinical syndromes, including diarrhoeal disease, caused by a large number of non-typhoidal salmonella serovars (NTS). Typhoid is a human-restricted and highly adapted invasive disease, but shows little association with immunocompromise. In contrast, NTS have a broad vertebrate host range, epidemiology that often involves food animals, and have a dramatically more severe and invasive presentation in immunocompromised adults, in particular in the context of HIV. Immunocompromise among adults, including underlying severe or progressive disease, chronic granulomatous disease, defects or blockade of specific cytokines (particularly IL-12/IL-23/IL-17 and TNF), and HIV, is associated with suppurative foci and with primary bacteraemic disease, which may be recurrent. These patients have markedly increased mortality. Worldwide, invasive recurrent NTS bacteraemia associated with advanced HIV disease is a huge problem, and the epidemiology in this context may be more human-restricted than in other settings. This review will describe the presentation and pathogenesis of NTS in different categories of immunocompromised adults, contrasted to typhoid fever.
Collapse
Affiliation(s)
- Melita A Gordon
- Division of Gastroenterology, Henry Wellcome Laboratories, Nuffield Building, Crown Street, Liverpool University L69 3GE, UK.
| |
Collapse
|
|
13
|
Cat TB, Charash W, Hebert J, Marden BT, Corbett SM, Ahern J, Rebuck JA. Potential influence of antisecretory therapy on the development of Candida-associated intraabdominal infection. Ann Pharmacother 2008; 42:185-91. [PMID: 18212256 DOI: 10.1345/aph.1k328] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Concerns surrounding the potential extra gut complication of gastric acid suppression are becoming increasingly realized. OBJECTIVE To determine whether chronic antisecretory treatment with a proton pump inhibitor (PPI) or histamine(2)-receptor antagonist (H(2)RA) is associated with the presence of Candida spp. in cases of complicated intraabdominal infection. METHODS We conducted a case-controlled study of adult surgical intensive care unit patients with complicated intraabdominal infection during a 5-year period. Exclusion criteria consisted of primary peritonitis, diagnosis of intraabdominal infection more than 72 hours before hospital admission, or a stay in the intensive care unit of less than 72 hours. Patients were categorized into either the antisecretory group (H(2)RA or PPI therapy prior to admission) or control group (no prior antisecretory therapy). RESULTS One hundred eighteen patients met inclusion criteria. Chronic antisecretory (n = 41) and control (n = 77) patients were similar except in median age (69.0 vs 59.0 y; p = 0.026) and preadmission antibiotic use (36.6% vs 15.6%; p = 0.010). The 2 groups had a similar proportion of patients with Candida (30.3% vs 32.1%; p = 0.857); the cultures included C. albicans, C. glabrata, and C. parapsilosis. Yeast was recovered more often in patients diagnosed with community-acquired intraabdominal infection and in patients who had used PPIs before hospital admission (p = 0.066). Additionally, Candida was cultured more often in antisecretory patients with a history of prior abdominal surgery than in control patients (91.7% vs 62.5%; p = 0.066). CONCLUSIONS No significant difference was found in the number of patients in the antisecretory and control groups from whom peritoneal Candida was recovered. However, patients with prior abdominal surgery and those in the community with chronic PPI use may be predisposed to Candida-associated intraabdominal infections.
Collapse
Affiliation(s)
- Tram B Cat
- Department of Pharmacy, Antelope Valley Hospital, Lancaster, CA, USA
| | | | | | | | | | | | | |
Collapse
|
|
14
|
Windle HJ, Kelleher D, Crabtree JE. Childhood Helicobacter pylori infection and growth impairment in developing countries: a vicious cycle? Pediatrics 2007; 119:e754-9. [PMID: 17325213 DOI: 10.1542/peds.2006-2196] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We hypothesize that infection with the gastric pathogen Helicobacter pylori in children in developing countries is the initiator of a vicious cycle of events that result ultimately in malnutrition and growth impairment. Acute infection with H. pylori is accompanied by hypochlorhydria, which facilitates the acquisition of other enteropathogens because of removal of the gastric acid barrier, which then results in diarrheal disease and iron-deficiency anemia. This is likely to occur most frequently in developing regions where the prevalence of H. pylori infection is disproportionately high and multiple enteric coinfections are common. The consequent synergistic impact of diarrheal disease and micronutrient deficiency on growth and cognitive function in children has significant public health implications for socioeconomic development in these countries.
Collapse
Affiliation(s)
- Henry J Windle
- School of Medicine, Trinity College Dublin and Dublin Molecular Medicine Centre, Dublin, Ireland
| | | | | |
Collapse
|
|
15
|
Abstract
All vertebrates produce gastric acid. Its main function is inactivation of ingested microorganisms. The majority of microbiological pathogens ingested never reaches the intestine because of the gastric barrier. Although gastric hypochlorhydria is fairly common due to atrophic gastritis, gastric surgery or use of inhibitors of gastric acid secretion, the resulting susceptibility to infection has not been studied extensively. Drug-induced blockade of acid secretion leads to gastrointestinal bacterial overgrowth; the clinical significance of this is still controversial. Gastric acidity is known to protect against non-typhoid salmonellosis and cholera and it is suspected that it protects against several parasitic diseases as giardiasis and strongyloides. There is a lack of studies focusing on the impact of the gastric acidic barrier on viral infections. Concerning prion infections only a single study has been performed, demonstrating a possible role of gastric acidity in the protection against foodborne prion disease in mice. The combination of malnutrition and hypochlorhydria may contribute to the high prevalence of gastrointestinal infections in developing countries. Further studies are needed to evaluate the clinical consequences of impaired gastric acidity with respect to susceptibility to infections.
Collapse
Affiliation(s)
- Tom C Martinsen
- Department of Cancer Research and Molecular Medicine, Children's and Women's Health, Norwegian University of Science and Technology and University Hospital of Trondheim, Norway.
| | | | | |
Collapse
|
|
16
|
|
|
17
|
Passaro DJ, Taylor DN, Gilman RH, Cabrera L, Parsonnet J. Growth slowing after acute Helicobacter pylori infection is age-dependent. J Pediatr Gastroenterol Nutr 2002; 35:522-6. [PMID: 12394378 DOI: 10.1097/00005176-200210000-00012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Most infections occur during childhood, but the health effects of childhood infection are poorly understood. We investigated whether growth decreases in the 2 months after acute seroconversion. METHODS We performed a nested case-control study among children 6 months to 12 years of age in a community on the outskirts of Lima, Peru. Health interviews were completed daily. Anthropometric measurements were taken monthly. Sera were collected every 4 months and tested for immunoglobulin G. Two-month height and weight gains of seroconverters were compared with gains of sex, age, and size-matched seronegative controls. RESULTS In the 2 months after infection, 26 seroconverters gained a median of 24% less weight than 26 matched controls (interquartile range, 63% less to 21% more). In multivariate analysis, infection attenuated weight gain only among children aged 2 years or older. This decrease was not explained by increased diarrhea. CONCLUSIONS seroconversion is associated with a slowing of weight gain in children aged 2 years or older. Reasons for this finding merit additional study.
Collapse
Affiliation(s)
- Douglas J Passaro
- Division of Infectious Diseases and Geographic Medicine, Stanford University Medical Center, California, USA.
| | | | | | | | | |
Collapse
|
|
18
|
Laine L, Ahnen D, McClain C, Solcia E, Walsh JH. Review article: potential gastrointestinal effects of long-term acid suppression with proton pump inhibitors. Aliment Pharmacol Ther 2000; 14:651-68. [PMID: 10848649 DOI: 10.1046/j.1365-2036.2000.00768.x] [Citation(s) in RCA: 171] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This review examines the evidence for the development of adverse effects due to prolonged gastric acid suppression with proton pump inhibitors. Potential areas of concern regarding long-term proton pump inhibitor use have included: carcinoid formation; development of gastric adenocarcinoma (especially in patients with Helicobacter pylori infection); bacterial overgrowth; enteric infections; and malabsorption of fat, minerals, and vitamins. Prolonged proton pump inhibitor use may lead to enterochromaffin-like cell hyperplasia, but has not been demonstrated to increase the risk of carcinoid formation. Long-term proton pump inhibitor treatment has not been documented to hasten the development or the progression of atrophic gastritis to intestinal metaplasia and gastric cancer, although long-term studies are required to allow definitive conclusions. At present, we do not recommend that patients be tested routinely for H. pylori infection when using proton pump inhibitors for prolonged periods. Gastric bacterial overgrowth does increase with acid suppression, but important clinical sequelae, such a higher rate of gastric adenocarcinoma, have not been seen. The risk of enteric infection may increase with acid suppression, although this does not seem to be a common clinical problem with prolonged proton pump inhibitor use. The absorption of fats and minerals does not appear to be significantly impaired with chronic acid suppression. However, vitamin B12 concentration may be decreased when gastric acid is markedly suppressed for prolonged periods (e.g. Zolllinger-Ellison syndrome), and vitamin B12 levels should probably be assessed in patients taking high-dose proton pump inhibitors for many years. Thus, current evidence suggests that prolonged gastric acid suppression with proton pump inhibitors rarely, if ever, produces adverse events. Nevertheless, continued follow-up of patients taking proton pump inhibitors for extended periods will provide greater experience regarding the potential gastrointestinal adverse effects of long-term acid suppression.
Collapse
Affiliation(s)
- L Laine
- University of Southern California School of Medicine, Los Angeles, California 90033, USA.
| | | | | | | | | |
Collapse
|
|
19
|
Darwin KH, Miller VL. Molecular basis of the interaction of Salmonella with the intestinal mucosa. Clin Microbiol Rev 1999; 12:405-28. [PMID: 10398673 PMCID: PMC100246 DOI: 10.1128/cmr.12.3.405] [Citation(s) in RCA: 270] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Salmonella is one of the most extensively characterized bacterial pathogens and is a leading cause of bacterial gastroenteritis. Despite this, we are only just beginning to understand at a molecular level how Salmonella interacts with its mammalian hosts to cause disease. Studies during the past decade on the genetic basis of virulence of Salmonella have significantly advanced our understanding of the molecular basis of the host-pathogen interaction, yet many questions remain. In this review, we focus on the interaction of enterocolitis-causing salmonellae with the intestinal mucosa, since this is the initiating step for most infections caused by Salmonella. Animal and in vitro cell culture models for the interaction of these bacteria with the intestinal epithelium are reviewed, along with the bacterial genes that are thought to affect this interaction. Lastly, recent studies on the response of epithelial cells to Salmonella infection and how this might promote diarrhea are discussed.
Collapse
Affiliation(s)
- K H Darwin
- Departments of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | |
Collapse
|
|
20
|
Kingsley RA, Reissbrodt R, Rabsch W, Ketley JM, Tsolis RM, Everest P, Dougan G, Bäumler AJ, Roberts M, Williams PH. Ferrioxamine-mediated Iron(III) utilization by Salmonella enterica. Appl Environ Microbiol 1999; 65:1610-8. [PMID: 10103258 PMCID: PMC91228 DOI: 10.1128/aem.65.4.1610-1618.1999] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/1998] [Accepted: 01/21/1999] [Indexed: 11/20/2022] Open
Abstract
Utilization of ferrioxamines as sole sources of iron distinguishes Salmonella enterica serotypes Typhimurium and Enteritidis from a number of related species, including Escherichia coli. Ferrioxamine supplements have therefore been used in preenrichment and selection media to increase the bacterial growth rate while selectivity is maintained. We characterized the determinants involved in utilization of ferrioxamines B, E, and G by S. enterica serotype Typhimurium by performing siderophore cross-feeding bioassays. Transport of all three ferric siderophores across the outer membrane was dependent on the FoxA receptor encoded by the Fur-repressible foxA gene. However, only the transport of ferrioxamine G was dependent on the energy-transducing protein TonB, since growth stimulation of a tonB strain by ferrioxamines B and E was observed, albeit at lower efficiencies than in the parental strain. Transport across the inner membrane was dependent on the periplasmic binding protein-dependent ABC transporter complex comprising FhuBCD, as has been reported for other hydroxamate siderophores of enteric bacteria. The distribution of the foxA gene in the genus Salmonella, as indicated by DNA hybridization studies and correlated with the ability to utilize ferrioxamine E, was restricted to subspecies I, II, and IIIb, and this gene was absent from subspecies IIIa, IV, VI, and VII (formerly subspecies IV) and Salmonella bongori (formerly subspecies V). S. enterica serotype Typhimurium mutants with either a transposon insertion or a defined nonpolar frameshift (+2) mutation in the foxA gene were not able to utilize any of the three ferrioxamines tested. A strain carrying the nonpolar foxA mutation exhibited a significantly reduced ability to colonize rabbit ileal loops compared to the foxA+ parent. In addition, a foxA mutant was markedly attenuated in mice inoculated by either the intragastric or intravenous route. Mice inoculated with the foxA mutant were protected against subsequent challenge by the foxA+ parent strain.
Collapse
Affiliation(s)
- R A Kingsley
- Department of Microbiology and Immunology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | | | | | | | | | | | | | | | | | | |
Collapse
|
|
21
|
Mossel DA, Weenk GH, Morris GP, Struijk CB. Identification, assessment and management of food-related microbiological hazards: historical, fundamental and psycho-social essentials. Int J Food Microbiol 1998; 39:19-51. [PMID: 9562875 DOI: 10.1016/s0168-1605(97)00115-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Microbiological risk assessment aimed at devising measures of hazard management, should take into account all perceived hazards, including those not empirically identified. It should also recognise that safety cannot be "inspected into" a food. Rather hazard management should be the product of intervention strategies in accordance with the approach made mandatory in the EU Directive 93/43 and the USDA FSIS Pathogen Reduction HACCP system; Final Rule. It is essential too that the inherent variability of the biological attributes affecting food safety is recognised in any risk assessment. The above strategic principles may be conceptualised as a four-step sequence, involving (i) identification and quantification of hazards; (ii) design and codification of longitudinally integrated ("holistic") technological processes and procedures to eliminate, or control growth and metabolism of, pathogenic and toxinogenic organisms; (iii) elaboration of microbiological analytical standard operating procedures, permitting validation of "due diligence" or responsible care, i.e. adherence to adopted intervention strategies. This should be supported by empirically assessed reference ranges, particularly for marker organisms, while the term "zero tolerance" is refined throughout to tolerable safety limit; (iv) when called for, the need to address concerns arising from lay perceptions of risk which may lack scientific foundation. In relation to infectious and toxic hazards in the practical context the following general models for quantitative holistic risk assessment are presented: (i) the first order, basic lethality model; (ii) a second approximation taking into account the amount of food ingested in a given period of time; (iii) a further adjustment accounting for changes in colonization levels during storage and distribution of food commodities and the effects of these on proliferation of pathogens and toxin production by bacteria and moulds. Guidelines are provided to address: (i) unsubstantiated consumer concern over the wholesomeness of foods processed by an innovative procedure; and (ii) reluctance of small food businesses to adopt novel strategies in food safety. Progress here calls for close cooperation with behavioural scientists to ensure that investment in developing measures to contain risk deliver real benefit.
Collapse
Affiliation(s)
- D A Mossel
- Eijkman Foundation, Utrecht University, Netherlands
| | | | | | | |
Collapse
|
|
22
|
Klontz KC, Adler WH, Potter M. Age-dependent resistance factors in the pathogenesis of foodborne infectious disease. AGING (MILAN, ITALY) 1997; 9:320-6. [PMID: 9458992 DOI: 10.1007/bf03339610] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
With increasing age there is an increase in both the incidence as well as the mortality due to many infectious illnesses, and foodborne infectious disease is no exception. A review of the pertinent literature identified studies concerning foodborne disease caused by infectious agents in the elderly, as well as those factors that could account for the increase in morbidity and mortality seen in the elderly due to foodborne infections. The published information suggested that the basis for the increased incidence, severity and risk of death of many foodborne infectious diseases in elderly persons is related to factors such as reduced gastric acidity, a higher prevalence of underlying medical disorders (co-morbidity factors), and immune system changes that result in a less effective host defense against infectious agents. The greater risk of foodborne disease experienced by elderly persons results from the contribution of non-immune and immune mediated factors. Due to the growing number of persons over the age of 65 years in the United States, foodborne disease in this age group will continue to be an important source of illness and death in the population.
Collapse
Affiliation(s)
- K C Klontz
- Epidemiology Branch, HFS-728, Food and Drug Administration, Washington, D.C. 20204, USA
| | | | | |
Collapse
|
|
23
|
Rushdy AA, Wall R, Seng C, Wall PG, Stuart JM, Ridley AM, Threlfall EJ, Ward LR. Application of molecular methods to a nosocomial outbreak of Salmonella enteritidis phage type 4. J Hosp Infect 1997; 36:123-31. [PMID: 9211159 DOI: 10.1016/s0195-6701(97)90118-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A nosocomial outbreak of Salmonella enteritidis phage type 4 occurred in July 1995. Seven definite cases were identified over 13 days affecting four wards in a London hospital. The outbreak strain was characterized by plasmid profile typing and pulsed-field gel electrophoresis (PFGE), and was unusual in that it did not possess a 38 MDa plasmid common to most isolates of S. enteritidis PT 4 made from humans and food animals in England and Wales. Seven asymptomatic excreters were identified on screening. No additional cases occurred on wards after standard isolation procedures were implemented. No common or continuing food or dietary source was identified. Results of epidemiological, microbiological and environmental investigations suggested that the outbreak was due to person-to-person transmission within the hospital. The source of the outbreak was not established but was probably due to admission of a patient with an unrecognized infection of S. enteritidis PT 4. The study highlights the importance of close collaboration between hospital staff, epidemiologists and microbiologists, and demonstrates the value of molecular techniques for strain subdivision in outbreak investigations.
Collapse
Affiliation(s)
- A A Rushdy
- PHLS Communicable Disease Surveillance Centre, London, UK
| | | | | | | | | | | | | | | |
Collapse
|
|
24
|
Sim M, Fairley C, McNeil J. Drinking water quality: new challenges for an old problem. Occup Environ Med 1996; 53:649-51. [PMID: 8943827 PMCID: PMC1128569 DOI: 10.1136/oem.53.10.649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
|
25
|
Abstract
Quantitative cultures were carried out on samples from gastric juice obtained from 12 ambulatory patients with esophagitis before and one month after omeprazole therapy. An increase in the number of patients in whom gastric juice was culture-positive, as well as an increment in the bacterial counts were noted. The spectrum of microorganisms isolated from gastric juice was identical to the normal flora of the oral cavity, mainly alpha-hemolytic streptococci, corynebacteria, and Candida species. Thus, the counts of organisms within gastric contents are simply a reflection of swallowed oral microflora that were able to survive due to the less acidic environment.
Collapse
Affiliation(s)
- Y Karmeli
- Department of Internal Medicine, Hadassah Medical Center, Jerusalem, Israel
| | | | | | | |
Collapse
|
|
26
|
Yeomans ND, Brimblecombe RW, Elder J, Heatley RV, Misiewicz JJ, Northfield TC, Pottage A. Effects of acid suppression on microbial flora of upper gut. Dig Dis Sci 1995; 40:81S-95S. [PMID: 7859586 DOI: 10.1007/bf02214873] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Decreased acid secretion, due to therapy or disease, predisposes to increased bacterial counts in gastric juice. As bacterial numbers increase, the number of nitrate-reducing strains and the concentration of luminal nitrite usually also increase. However, there is controversy (mainly because of assay problems) about whether decreased acid increases generation of N-nitroso compounds: these may be produced by acid or by bacterial catalysis, and the relative contributions of each are still uncertain. Other potentially important factors include ascorbate secretion (can prevent nitrite conversion to nitroso compounds) and the particular spectrum of nitroso compounds produced. Nitrosation of several histamine H2-receptor antagonists has been demonstrated experimentally, but under conditions that are very unlikely to be encountered clinically. Some acid suppressant therapies have been claimed to aid eradication of Helicobacter pylori, but more work is needed to evaluate this. If ulcer treatment regimens do not also address eradication of H. pylori (when present), gastritis will progress, and the recently documented association between H. pylori and gastric carcinoma needs to be considered. Enteric flora probably also increase if acid secretion is markedly reduced: this does not appear to have nutritional consequences but probably reduces the resistance to occasional infections, of which cholera is the best documented.
Collapse
Affiliation(s)
- N D Yeomans
- University of Melbourne Department of Medicine, Western Hospital, Australia
| | | | | | | | | | | | | |
Collapse
|
|
27
|
Noriega LM, Van der Auwera P, Daneau D, Meunier F, Aoun M. Salmonella infections in a cancer center. Support Care Cancer 1994; 2:116-22. [PMID: 8156265 DOI: 10.1007/bf00572093] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Data concerning 40 patients hospitalized in a cancer center and Salmonella infection were analyzed. Hematological malignancy was present in 24 patients (60%) and solid tumor in 14 patients (35%). Among the predisposing factors, antineoplastic chemotherapy was the most frequent (60%) followed by antacid use (47.5%), corticosteroids (37.5%), granulocytopenia below 500 neutrophils/microliters (15%), surgery (10%) and splenectomy (2.5%). Bacteremia was the most frequent clinical syndrome accounting for 42.5% of the patients. Focal infection, enteritis and carrier state accounted for the remaining 30%, 20% and 7.5% respectively. Salmonella typhimurium and S. dublin represented 65% of the isolates, with clear association between serotype dublin and bacteremia. All S. dublin isolates were resistant to chloramphenicol. Among dublin and typhimurium serotypes, 20% the isolates were resistant to the traditional antibiotics used in salmonellosis (ampicillin, chloramphenicol, cotrimoxazole). All strains were susceptible in vitro to cephalosporins. The frequency of relapse was 15% and the overall mortality (within 30 days) attributed to Salmonella infection was 15%.
Collapse
Affiliation(s)
- L M Noriega
- Servicio Medecina Interna, Hospital Dipreca, Los Condes, Santiago, Chile
| | | | | | | | | |
Collapse
|
|
28
|
Schlech WF, Chase DP, Badley A. A model of food-borne Listeria monocytogenes infection in the Sprague-Dawley rat using gastric inoculation: development and effect of gastric acidity on infective dose. Int J Food Microbiol 1993; 18:15-24. [PMID: 8466809 DOI: 10.1016/0168-1605(93)90003-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Recent epidemiological evidence suggests that Listeria monocytogenes (LM) is a food-borne pathogen in humans. A model of LM infection was developed using the Sprague-Dawley (SD) rat to study the interaction of LM with gastrointestinal epithelium as the first step in the pathogenesis of invasive listeriosis. Conventionally raised, juvenile female SD rats were given 10(2)-10(9) virulent L. monocytogenes, serotype 4b or nonpathogenic Listeria species. Only rats given virulent LM developed dose-dependent invasive infection of the liver and spleen. Light and electron microscopic studies suggested attachment to and invasion of the gastrointestinal mucosa by virulent LM. Because the development of invasive listeriosis in humans has been epidemiologically associated with a decrease in gastric acidity, the effect of decreasing gastric acidity on dose-dependent infection was studied. Rats were pretreated with cimetidine (50 mg/kg) by intraperitoneal injection prior to oral inoculation of 10(2)-10(9) virulent L. monocytogenes. Cimetidine significantly lowered the infective dose of virulent L. monocytogenes (P < 0.05). This oral model should allow further study of host and organism-specific virulence factors mediating the gastrointestinal phase of invasive LM infection, an increasingly important public health problem.
Collapse
Affiliation(s)
- W F Schlech
- Department of Medicine, Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada
| | | | | |
Collapse
|
|
29
|
Abstract
Gastric acid secretion was studied in 20 patients with typhoid fever (Group A), ten patients with fever other than typhoid (Group B), and ten healthy adults of matched age and sex (Group C). Patients with typhoid showed reduced acid secretion at the time of fever and one week after subsidence of fever as compared to Group C. In uncomplicated patients (Group A1), these values rose thereafter but in complicated patients (Group A2) they remained low even 12 weeks after subsidence of fever. This suggests that these patients had pre-existing hypochlorhydria which predisposed them to a severe form of disease. There may be many factors playing a significant role in making typhoid patients more prone to develop complications but the importance of gastric acid levels has also to be considered.
Collapse
Affiliation(s)
- S N Khosla
- Department of Medicine, Medical College & Hospital, Rohtak, Haryana, India
| | | | | |
Collapse
|
|
30
|
Navarro M, Almirante B, Bellmunt J, Jolis L. Fatal septic thrombophlebitis due to Salmonella enteritidis. Eur J Clin Microbiol Infect Dis 1989; 8:82-3. [PMID: 2495956 DOI: 10.1007/bf01964125] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The case is reported of a patient with gastric adenocarcinoma with metastases who developed a septic focus in a saphenous vein. Salmonella enteritidis was cultured from blood, sputum and stool specimens, and from a thrombus removed from a varicosity of the saphenous vein. Extraintestinal infections caused by non-typhoid salmonella usually afflict debilitated and immunocompromised patients. Metastatic septic foci may appear anywhere in the organism, including the vascular system, but involvement of the venous system has not previously been reported.
Collapse
Affiliation(s)
- M Navarro
- Department of Radiotherapy and Oncology, Valle Hebron Hospital, Barcelona, Spain
| | | | | | | |
Collapse
|
|
31
|
Ainley CC, Clarke DG, Timothy AR, Thompson RP. Strongyloides stercoralis hyperinfection associated with cimetidine in an immunosuppressed patient: diagnosis by endoscopic biopsy. Gut 1986; 27:337-8. [PMID: 3699555 PMCID: PMC1433427 DOI: 10.1136/gut.27.3.337] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Immunosuppression causes Strongyloides stercoralis hyperinfection, but other factors may also be involved. We report a case of S stercoralis hyperinfection in an immunosuppressed patient that followed cimetidine therapy and was diagnosed by endoscopic biopsy.
Collapse
|
|
32
|
Axon AT. Potential hazards of hypochlorhydria in the treatment of peptic ulcer. SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY. SUPPLEMENT 1986; 122:17-21. [PMID: 3535017 DOI: 10.3109/00365528609102581] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The introduction of ulcer-healing drugs that do not induce hypochlorhydria--the main aim of therapy thus far--has led to the consideration of the possible disadvantages of acid secretion inhibition. Potential dangers are that micro-organisms destroyed by the normal stomach survive and proliferate in the stomach and small intestine. The incidence of gastric cancer is higher in pernicious anemia and after partial gastrectomy. It has been suggested that the intragastric bacteria may convert dietary nitrate into nitrite that may then be nitrosated to carcinogenic N-nitroso compounds. The third potential hazard is the development of stagnant loop syndrome in patients treated with H2 antagonists. In a double-blind randomised trial of colloidal bismuth subcitrate (CBS) versus cimetidine in duodenal ulcer, gastric juice was aspirated for pH measurement. There was a significant increase in the total number of bacteria isolated during cimetidine treatment (P less than 0.01) and an increase in nitrate-reducing organisms (P less than 0.05), but no change in the CBS group. It is concluded that there may be advantages in using ulcer-healing drugs that do not reduce H+ concentration.
Collapse
|
|
33
|
Cook GC. Infective gastroenteritis and its relationship to reduced gastric acidity. SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY. SUPPLEMENT 1985; 111:17-23. [PMID: 3925541 DOI: 10.3109/00365528509093751] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Hypochlorhydria by compromising the defence mechanisms of the upper gastrointestinal tract predisposes to intestinal bacterial and parasitic infections. Achlorhydria predisposes to anaerobic colonization of the small intestine; colonization is far greater than in normal subjects even with partial neutralization of their gastric acidity after a meal. The best evidence for increased incidence of specific bacterial infection in the presence of achlorhydria relates to the nontyphoid salmonelloses. There is also strongly suggestive evidence in cholera. Among parasitic infections, the most impressive evidence relates to giardiasis and strongyloidiasis. In some instances, the infections themselves may also cause hypochlorhydria. Longitudinal studies are required. Whether patients receiving H2-receptor antagonists are unduly vulnerable to gastrointestinal infections is unclear. The importance of hypochlorhydria in 'Third World' populations, in whom gastrointestinal infections are extremely common, especially in infancy, is, at present, also impossible to evaluate.
Collapse
|
|
34
|
Stockbruegger RW. Bacterial overgrowth as a consequence of reduced gastric acidity. SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY. SUPPLEMENT 1985; 111:7-16. [PMID: 2861652 DOI: 10.3109/00365528509093749] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Reduction in acid secretion in atrophic gastritis allows bacterial colonization of the stomach, most extremely in achlorhydric patients with pernicious anaemia, in whom overgrowth may cause nitrate reduction and formation of potentially carcinogenic N-nitroso compounds. Subsequent bacterial contamination of the upper small intestine can induce mucosal damage and malabsorption. The situation is similar after gastrectomy. In achlorhydria and after gastrectomy, the risk of gastric cancer is increased. There is controversy as to the risks of long-term treatment with H2-receptor antagonists. Increase in nitrate-reducing bacteria, nitrite and N-nitrosamine have been observed in patients by some investigators but not in volunteers and patients by others. Bacterial concentrations after cimetidine are inversely related to pretreatment acid secretory capacity. Demonstration of increased mutagenicity of gastric juice after H2-receptor antagonists gives grounds for caution. Drastic acid reduction may in future be reserved for short-term and intermittent treatment and mild or moderate reduction for long-term treatment of peptic ulcer and ulcer prevention.
Collapse
|
|
35
|
|
|
36
|
|
|
37
|
|
|
38
|
TURNBULL PC. Food Poisoning with Special Reference to Salmonella — Its Epidemiology, Pathogenesis and Control. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/s0300-5089(21)00234-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
|
39
|
Steere AC, Hall WJ, Wells JG, Craven PJ, Leotsakis N, Farmer JJ, Gangarosa EJ. Person-to-person spread of Salmonella typhimurium after a hospital common-source outbreak. Lancet 1975; 1:319-22. [PMID: 46457 DOI: 10.1016/s0140-6736(75)91221-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In September, 1973, diarrhoea caused by Salmonella typhimurium developed in 32 people in a Maine hospital. Both epidemiological and microbiological evidence indicated that raw egg beaten in milk ("egg-nog") was responsible for the infection. However, 6 patients and 8 employees had not had egg-nog, and their illness developed after the source of infection had been recognised and removed. Most of these people had had direct contact with an infected patient, and presumably acquired the infection by person-to-person spread. It is concluded that person-to-person spread of S. typhimurium can occur in hospitals and can be a hazard to patients and staff.
Collapse
|
|
40
|
Bjorneboe M, Prytz H. Failure of diseased liver to inhibit immunogens. Lancet 1973; 1:1521-2. [PMID: 4123194 DOI: 10.1016/s0140-6736(73)91870-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
|
41
|
Constantopoulos A, Economopoulos P, Kandylas J. Fulminant diarrhoea and acute haemolysis due to G.-6-P.D. deficiency in salmonellosis. Lancet 1973; 1:1522. [PMID: 4123195 DOI: 10.1016/s0140-6736(73)91871-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
|
42
|
Giannella RA, Formal SB, Dammin GJ, Collins H. Pathogenesis of salmonellosis. Studies of fluid secretion, mucosal invasion, and morphologic reaction in the rabbit ileum. J Clin Invest 1973; 52:441-53. [PMID: 4630603 PMCID: PMC302274 DOI: 10.1172/jci107201] [Citation(s) in RCA: 145] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Strains of Salmonella typhimurium were studied in the ligated rabbit ileal loop model to gain insight into the mechanisms whereby bacteria which invade the gastrointestinal mucosa evoke fluid exsorption. The organisms employed differed in various biologic attributes including the ability to invade the ileal epithelium, multiply within the mucosa, elicit an acute inflammatory reaction, and disseminate across the intestinal wall. Some strains provoked small intestinal fluid exsorption although these did not elaborate enterotoxin. Only those strains which invaded the mucosa were accompanied by either mucosal inflammation or fluid exsorption. Noninvasive strains produced neither histologic abnormalities nor fluid secretion. While strains which invaded the mucosa caused an acute inflammatory reaction, not all such strains evoked fluid secretion. Furthermore, there was no correlation in ability of invasive organisms to evoke fluid secretion or in the intensity of mucosal inflammation, number of intramucosal salmonellae, or in ability to disseminate from the rabbit ileum. These observations suggest that, as is the case in shigellosis, mucosal invasion may be a necessary factor for the intestinal fluid loss in salmonellosis. A bacterial property or factor, in addition to invasion of the gastrointestinal mucosa, seems to be responsible for fluid exsorptin. However, it is unlikely that a salmonella enterotoxin comparable to that elaborated by Vibrio cholerae, toxigenic Escherichia coli, or Shigella dysenteriae 1 is related to fluid secretion in salmonellosis.
Collapse
|
|
43
|
Giannella RA, Broitman SA, Zamcheck N. Salmonella enteritis. II. Fulminant diarrhea in and effects on the small intestine. THE AMERICAN JOURNAL OF DIGESTIVE DISEASES 1971; 16:1007-13. [PMID: 5128594 DOI: 10.1007/bf02235013] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|