1
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Fieldman T. Evolutionary principles for modifying pathogen virulence. Crit Rev Microbiol 2024; 50:385-396. [PMID: 37146153 DOI: 10.1080/1040841x.2023.2203766] [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: 12/21/2022] [Revised: 03/31/2023] [Accepted: 04/10/2023] [Indexed: 05/07/2023]
Abstract
Current methods for combatting infectious diseases are largely limited to the prevention of infection, enhancing host immunity (via vaccination), and administration of small molecules to slow the growth of or kill pathogens (e.g. antimicrobials). Beyond efforts to deter the rise of antimicrobial resistance, little consideration is given to pathogen evolution. Natural selection will favor different levels of virulence under different circumstances. Experimental studies and a wealth of theoretical work have identified many likely evolutionary determinants of virulence. Some of these, such as transmission dynamics, are amenable to modification by clinicians and public health practitioners. In this article, we provide a conceptual overview of virulence, followed by an analysis of modifiable evolutionary determinants of virulence including vaccinations, antibiotics, and transmission dynamics. Finally, we discuss both the importance and limitations of taking an evolutionary approach to reducing pathogen virulence.
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Affiliation(s)
- Tom Fieldman
- Clinical Microbiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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2
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Liu X, Qin P, Wen H, Wang W, Zhao J. Seasonal meropenem resistance in Acinetobacter baumannii and influence of temperature-driven adaptation. BMC Microbiol 2024; 24:149. [PMID: 38678219 PMCID: PMC11055336 DOI: 10.1186/s12866-024-03271-y] [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: 11/28/2023] [Accepted: 03/22/2024] [Indexed: 04/29/2024] Open
Abstract
BACKGROUND Recognition of seasonal trends in bacterial infection and drug resistance rates may enhance diagnosis, direct therapeutic strategies, and inform preventive measures. Limited data exist on the seasonal variability of Acinetobacter baumannii. We investigated the seasonality of A. baumannii, the correlation between temperature and meropenem resistance, and the impact of temperature on this bacterium. RESULTS Meropenem resistance rates increased with lower temperatures, peaking in winter/colder months. Nonresistant strain detection exhibited temperature-dependent seasonality, rising in summer/warmer months and declining in winter/colder months. In contrast, resistant strains showed no seasonality. Variations in meropenem-resistant and nonresistant bacterial resilience to temperature changes were observed. Nonresistant strains displayed growth advantages at temperatures ≥ 25 °C, whereas meropenem-resistant A. baumannii with β-lactamase OXA-23 exhibited greater resistance to low-temperature (4 °C) stress. Furthermore, at 4 °C, A. baumannii upregulated carbapenem resistance-related genes (adeJ, oxa-51, and oxa-23) and increased meropenem stress tolerance. CONCLUSIONS Meropenem resistance rates in A. baumannii display seasonality and are negatively correlated with local temperature, with rates peaking in winter, possibly linked to the differential adaptation of resistant and nonresistant isolates to temperature fluctuations. Furthermore, due to significant resistance rate variations between quarters, compiling monthly or quarterly reports might enhance comprehension of antibiotic resistance trends. Consequently, this could assist in formulating strategies to control and prevent resistance within healthcare facilities.
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Affiliation(s)
- Xiaoxuan Liu
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China
| | - Pu Qin
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China
| | - Hainan Wen
- Department of Laboratory Medicine, Affiliated Hospital of Chengde Medical University, Chengde, 067000, People's Republic of China
| | - Weigang Wang
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China
| | - Jianhong Zhao
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China.
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3
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Masset Z, Gunaratnam S, Millette M, McFarland LV, Lacroix M. Environmental and Nutritional Parameters Modulating Genetic Expression for Virulence Factors of Clostridioides difficile. Antibiotics (Basel) 2024; 13:365. [PMID: 38667041 PMCID: PMC11047382 DOI: 10.3390/antibiotics13040365] [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: 03/18/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024] Open
Abstract
Clostridioides difficile infections (CDIs) continue to be a persistent healthcare concern despite newer antibiotic treatments, enhanced infection control practices, and preventive strategies focused on restoring the protective intestinal microbial barrier. Recent strides in gene sequencing research have identified many genes regulating diverse virulence factors for CDIs. These genes may be over- or under-expressed when triggered by various environmental and nutritional factors. The aims of this paper are to review the important genes involved in C. difficile pathogenesis and to identify modifiable environmental, nutritional, and other factors that may trigger the expression of these genes and thus offer new strategies to prevent CDIs.
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Affiliation(s)
- Zoe Masset
- INRS Armand-Frappier Health Biotechnology Research Centre, Research Laboratories in Sciences, 531 des Prairies Blvd, Laval, QC H7V 1B7, Canada; (Z.M.); (M.L.)
| | - Sathursha Gunaratnam
- Bio-K+, a Kerry Company, Preclinical Research Division, 495 Armand-Frappier Blvd, Laval, QC H7V 4B3, Canada; (S.G.); (M.M.)
| | - Mathieu Millette
- Bio-K+, a Kerry Company, Preclinical Research Division, 495 Armand-Frappier Blvd, Laval, QC H7V 4B3, Canada; (S.G.); (M.M.)
| | - Lynne V. McFarland
- Public Health Reserves Corps, Seattle, WA 98115, USA
- McFarland Consulting, Seattle, WA 98115, USA
| | - Monique Lacroix
- INRS Armand-Frappier Health Biotechnology Research Centre, Research Laboratories in Sciences, 531 des Prairies Blvd, Laval, QC H7V 1B7, Canada; (Z.M.); (M.L.)
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4
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Chen J, Yu W, Zhang W, Sun C, Zhang W. Antibiotics-associated pseudomembranous colitis: a disproportionality analysis of the US food and drug administration adverse event reporting system (FAERS) database. Expert Opin Drug Saf 2024:1-7. [PMID: 38603461 DOI: 10.1080/14740338.2024.2341813] [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: 01/27/2024] [Accepted: 04/04/2024] [Indexed: 04/13/2024]
Abstract
BACKGROUND Evaluating antibiotics most commonly associated with pseudomembranous colitis (PMC) based on the real-world data is of great significance. RESEARCH DESIGN AND METHODS We used the data from FAERS to evaluate the potential association between antibiotics and PMC by disproportionality analyzes. RESULTS Eighty-one antibiotics which met the three algorithms simultaneously were enrolled. There were 1683 reports of PMC associated with the enrolled antibiotics. In the top 24 antibiotics, cefoxitin, streptomycin, fosfomycin, and micafungin had a high risk of PMC, but there were few reports in the literature. CONCLUSIONS This study was of great significance for healthcare professionals to realize the potential PMC risks of antibiotics.
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Affiliation(s)
- Jinhua Chen
- Department of Pharmacy, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Henan Engineering Research Center for Tumor Precision Medicine and Comprehensive Evaluation, Henan Provincial Key Laboratory of Anticancer Drug Research, Zhengzhou, China
| | - Weijiang Yu
- Department of Pharmacy, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Henan Engineering Research Center for Tumor Precision Medicine and Comprehensive Evaluation, Henan Provincial Key Laboratory of Anticancer Drug Research, Zhengzhou, China
| | - Wancun Zhang
- Health Commission of Henan Province Key Laboratory for Precision Diagnosis and Treatment of Pediatric Tumor, Department of Pediatric Oncology Surgery, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Cuicui Sun
- Department of Pharmacy, Qilu Hospital of Shandong University, Ji'nan, China
| | - Wenzhou Zhang
- Department of Pharmacy, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Henan Engineering Research Center for Tumor Precision Medicine and Comprehensive Evaluation, Henan Provincial Key Laboratory of Anticancer Drug Research, Zhengzhou, China
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5
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Yang J, Meng L, Li Y, Huang H. Strategies for applying probiotics in the antibiotic management of Clostridioides difficile infection. Food Funct 2023; 14:8711-8733. [PMID: 37725066 DOI: 10.1039/d3fo02110f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
The vital role of probiotics in the food field has been widely recognized, and at the same time, probiotics are gradually exhibiting surprising effects in the field of nutraceuticals, especially in regulating gut inflammation and the nutritional environment. As a dietary supplement in clinical nutrition, the coadministration of probiotics with antibiotics model has been applied to prevent intestinal infections caused by Clostridioides difficile. However, the mechanism behind this "bacteria-drug combination" model remains unclear. In particular, the selection of specific probiotic strains, the order of probiotics or antibiotics, and the time interval of coadministration are key issues that need to be further explored and clarified. Here, we focus on the issues mentioned above and give reasonable opinions, mainly including: (1) probiotics are safer and more effective when they intervene after antibiotics have been used; (2) the choice of the time interval between coadministration should be based on the metabolism of antibiotics in the host, differences in probiotic strains, the baseline ecological environment of the host's intestine, and the host immune level; in addition, the selection of the coadministration regime should also take into account factors such as the antibiotic sensitivity of probiotics and dosage of probiotics; and (3) by encapsulating probiotics, combining probiotics with prebiotics, and developing next-generation probiotics (NGPs) and postbiotic formulations, we can provide a more reasonable reference for this type of "bacteria-drug combination" model, and also provide targeted guidance for the application of probiotic dietary supplements in the antibiotic management of C. difficile infection.
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Affiliation(s)
- Jingpeng Yang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, China.
| | - Lingtong Meng
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, China.
| | - Yanan Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, China.
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, China.
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6
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Regulation of Clostridioides difficile toxin production. Curr Opin Microbiol 2022; 65:95-100. [PMID: 34781095 PMCID: PMC8792210 DOI: 10.1016/j.mib.2021.10.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/19/2021] [Accepted: 10/25/2021] [Indexed: 02/03/2023]
Abstract
Clostridioides difficile produces toxins TcdA and TcdB during infection. Since the severity of the illness is directly correlated with the level of toxins produced, researchers have long been interested in the regulation mechanisms of toxin production. The advent of new genetics and mutagenesis technologies in C. difficile has allowed a slew of new investigations in the last decade, which considerably improved our understanding of this crucial regulatory network. The current body of work shows that the toxin regulatory network overlaps with the regulatory networks of sporulation, motility, and key metabolic pathways. This implies that toxin production is a complicated process initiated by bacteria in response to numerous host factors during infection. We summarize the existing knowledge about the toxin gene regulatory network here.
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7
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Brauer M, Herrmann J, Zühlke D, Müller R, Riedel K, Sievers S. Myxopyronin B inhibits growth of a Fidaxomicin-resistant Clostridioides difficile isolate and interferes with toxin synthesis. Gut Pathog 2022; 14:4. [PMID: 34991700 PMCID: PMC8739712 DOI: 10.1186/s13099-021-00475-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 12/13/2021] [Indexed: 02/06/2023] Open
Abstract
The anaerobic, gastrointestinal pathogen Clostridioides difficile can cause severe forms of enterocolitis which is mainly mediated by the toxins it produces. The RNA polymerase inhibitor Fidaxomicin is the current gold standard for the therapy of C. difficile infections due to several beneficial features including its ability to suppress toxin synthesis in C. difficile. In contrast to the Rifamycins, Fidaxomicin binds to the RNA polymerase switch region, which is also the binding site for Myxopyronin B. Here, serial broth dilution assays were performed to test the susceptibility of C. difficile and other anaerobes to Myxopyronin B, proving that the natural product is considerably active against C. difficile and that there is no cross-resistance between Fidaxomicin and Myxopyronin B in a Fidaxomicin-resistant C. difficile strain. Moreover, mass spectrometry analysis indicated that Myxopyronin B is able to suppress early phase toxin synthesis in C. difficile to the same degree as Fidaxomicin. Conclusively, Myxopyronin B is proposed as a new lead structure for the design of novel antibiotics for the therapy of C. difficile infections.
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Affiliation(s)
- Madita Brauer
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Jennifer Herrmann
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Saarbrücken, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Daniela Zühlke
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)-Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Saarbrücken, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Katharina Riedel
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Susanne Sievers
- Institute of Microbiology, University of Greifswald, Greifswald, Germany.
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8
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Goneau LW, Delport J, Langlois L, Poutanen SM, Razvi H, Reid G, Burton JP. Issues beyond resistance: inadequate antibiotic therapy and bacterial hypervirulence. FEMS MICROBES 2020; 1:xtaa004. [PMID: 37333955 PMCID: PMC10117437 DOI: 10.1093/femsmc/xtaa004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/15/2020] [Indexed: 10/15/2023] Open
Abstract
The administration of antibiotics while critical for treatment, can be accompanied by potentially severe complications. These include toxicities associated with the drugs themselves, the selection of resistant organisms and depletion of endogenous host microbiota. In addition, antibiotics may be associated with less well-recognized complications arising through changes in the pathogens themselves. Growing evidence suggests that organisms exposed to antibiotics can respond by altering the expression of toxins, invasins and adhesins, as well as biofilm, resistance and persistence factors. The clinical significance of these changes continues to be explored; however, it is possible that treatment with antibiotics may inadvertently precipitate a worsening of the clinical course of disease. Efforts are needed to adjust or augment antibiotic therapy to prevent the transition of pathogens to hypervirulent states. Better understanding the role of antibiotic-microbe interactions and how these can influence disease course is critical given the implications on prescription guidelines and antimicrobial stewardship policies.
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Affiliation(s)
- Lee W Goneau
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
- Lawson Health Research Institute, 268 Grosvenor St, London, Ontario, N6A 4V2 Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto,1 King's College Cir, Toronto, ON M5S 1A8 Ontario, Canada
| | - Johannes Delport
- Department of Pathology, London Health Sciences Center - Victoria Hospital, 800 Commissioners Rd E, London, Ontario, Canada N6A 5W9
| | - Luana Langlois
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Susan M Poutanen
- Department of Laboratory Medicine and Pathobiology, University of Toronto,1 King's College Cir, Toronto, ON M5S 1A8 Ontario, Canada
- Department of Medicine, University of Toronto, 1 King's College Cir, Toronto, ON M5S 1A8 Toronto, Ontario, Canada
- Department of Microbiology, University Health Network and Sinai Health, 190 Elizabeth St. Toronto, ON M5G 2C4, Ontario, Canada
| | - Hassan Razvi
- Lawson Health Research Institute, 268 Grosvenor St, London, Ontario, N6A 4V2 Canada
- Division of Urology, Department of Surgery, Western University, 1151 Richmond St, London, Ontario, N6A 3K7 Canada
| | - Gregor Reid
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
- Lawson Health Research Institute, 268 Grosvenor St, London, Ontario, N6A 4V2 Canada
- Division of Urology, Department of Surgery, Western University, 1151 Richmond St, London, Ontario, N6A 3K7 Canada
| | - Jeremy P Burton
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
- Lawson Health Research Institute, 268 Grosvenor St, London, Ontario, N6A 4V2 Canada
- Division of Urology, Department of Surgery, Western University, 1151 Richmond St, London, Ontario, N6A 3K7 Canada
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9
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Chilton CH, Crowther GS, Miossec C, de Gunzburg J, Andremont A, Wilcox MH. Investigation of the effect of the adsorbent DAV131A on the propensity of moxifloxacin to induce simulated Clostridioides (Clostridium) difficile infection (CDI) in an in vitro human gut model. J Antimicrob Chemother 2020; 75:1458-1465. [DOI: 10.1093/jac/dkaa062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/17/2020] [Accepted: 01/31/2020] [Indexed: 12/20/2022] Open
Abstract
Abstract
Background
Clostridioides difficile infection (CDI) remains a high burden worldwide. DAV131A, a novel adsorbent, reduces residual gut antimicrobial levels, reducing CDI risk in animal models.
Objectives
We used a validated human gut model to investigate the efficacy of DAV131A in preventing moxifloxacin-induced CDI.
Methods
C. difficile (CD) spores were inoculated into two models populated with pooled human faeces. Moxifloxacin was instilled (43 mg/L, once daily, 7 days) alongside DAV131A (5 g in 18 mL PBS, three times daily, 14 days, Model A), or PBS (18 mL, three times daily, 14 days, Model B). Selected gut microbiota populations, CD total counts, spore counts, cytotoxin titre and antimicrobial concentrations (HPLC) were monitored daily. We monitored for reduced susceptibility of CD to moxifloxacin. Growth of CD in faecal filtrate and medium in the presence/absence of DAV131A, or in medium pre-treated with DAV131A, was also investigated.
Results
DAV131A instillation reduced active moxifloxacin levels to below the limit of detection (50 ng/mL), and prevented microbiota disruption, excepting Bacteroides fragilis group populations, which declined by ∼3 log10 cfu/mL. DAV131A delayed onset of simulated CDI by ∼2 weeks, but did not prevent CD germination and toxin production. DAV131A prevented emergence of reduced susceptibility of CD to moxifloxacin. In batch culture, DAV131A had minor effects on CD vegetative growth, but significantly reduced toxin/spores (P < 0.005).
Conclusions
DAV131A reduced moxifloxacin-induced microbiota disruption and emergence of antibiotic-resistant CD. Delayed onset of CD germination and toxin production indicates further investigations are warranted to understand the clinical benefits of DAV131A in CDI prevention.
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Affiliation(s)
- C H Chilton
- Healthcare Associated Infections Research Group, Leeds Institute for Medical Research, University of Leeds, Old Medical School, Leeds General Infirmary, Leeds LS1 3EX, UK
| | - G S Crowther
- Division of Pharmacy and Optometry, University of Manchester, Manchester M13 9PT, UK
| | - C Miossec
- Da Volterra, Le Dorian (bât B1), 172 rue de Charonne, 75011 Paris, France
| | - J de Gunzburg
- Da Volterra, Le Dorian (bât B1), 172 rue de Charonne, 75011 Paris, France
| | - A Andremont
- IAME INSERM, UMR 1137, University of Paris, 75018 Paris, France
| | - M H Wilcox
- Healthcare Associated Infections Research Group, Leeds Institute for Medical Research, University of Leeds, Old Medical School, Leeds General Infirmary, Leeds LS1 3EX, UK
- Microbiology, Leeds Teaching Hospitals NHS Trust, Old Medical School, Leeds General Infirmary, Leeds LS1 3EX, UK
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10
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Yang J, Yang H. Non-antibiotic therapy for Clostridioides difficile infection: a review. Crit Rev Clin Lab Sci 2019; 56:493-509. [PMID: 31411909 DOI: 10.1080/10408363.2019.1648377] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Clostridioides difficile infection (CDI) is a common infectious disease that is mainly caused by antibiotics. Antibiotic therapy is still the dominant treatment for CDI, although it is accompanied by side effects. Probiotics, fecal microbiota transplantation (FMT), engineered microorganisms, bacteriophages, diet, natural active substances, nanoparticles and compounds are examples of emerging non-antibiotic therapies that have received a great amount of attention. In this review, we collected data about different non-antibiotic therapies for CDI and provided a comprehensive analysis and detailed comparison of these therapies. The mechanism of action, therapeutic efficacy, and the strengths and weaknesses of these non-antibiotic therapies have been investigated to provide a basis for the reasonable alternative of non-antibiotic therapies for CDI. In summary, probiotics and FMT are currently the best choice for non-antibiotic therapy for CDI.
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Affiliation(s)
- Jingpeng Yang
- State Key Laboratory of Microbial Metabolism, and School of Life Science & Biotechnology, Shanghai Jiao Tong University , Shanghai , China
| | - Hong Yang
- State Key Laboratory of Microbial Metabolism, and School of Life Science & Biotechnology, Shanghai Jiao Tong University , Shanghai , China
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11
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Pellissery AJ, Vinayamohan PG, Yin HB, Mooyottu S, Venkitanarayanan K. In vitro efficacy of sodium selenite in reducing toxin production, spore outgrowth and antibiotic resistance in hypervirulent Clostridium difficile. J Med Microbiol 2019; 68:1118-1128. [PMID: 31172910 DOI: 10.1099/jmm.0.001008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE This study investigated the efficacy of the essential mineral, selenium (sodium selenite), in reducing the toxin production, spore outgrowth and antibiotic resistance of Clostridium difficile in vitro. METHODOLOGY Two hypervirulent C. difficile isolates were cultured in brain heart infusion broth with and without a sub-minimum inhibitory concentration (sub-MIC) of sodium selenite, and the supernatant and bacterial pellet were harvested for total toxin quantitation and RT-qPCR analysis of toxin-encoding genes, respectively. Additionally, C. difficile isolates were cultured in brain heart infusion broth containing 0.5 or 1× the minimum inhibitory concentration (MIC) of either ciprofloxacin or vancomycin with or without sub-MICs of sodium selenite. Further, the effect of sodium selenite on C. difficile germination and spore outgrowth was also determined by exposing C. difficile spores to a sub-MIC of sodium selenite in a germination medium and measuring the germination and outgrowth by measuring the optical density at 600 nm. RESULTS Sodium selenite significantly reduced C. difficile toxin synthesis, cytotoxicity and spore outgrowth. Further, the expression of the toxin production genes, tcdA and tcdB, was downregulated in the presence of sodium selenite, while sodium selenite significantly increased the sensitivity of C. difficile to ciprofloxacin , but not vancomycin, as revealed by decreased bacterial growth in samples containing ciprofloxacin+selenium compared to the antibiotic control. Although the sub-MIC of sodium selenite did not inhibit spore germination, it was capable of completely inhibiting spore outgrowth. CONCLUSION Our results suggest that sodium selenite could potentially be used to control C. difficile and indicate that future in vivo studies are warranted.
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Affiliation(s)
| | | | | | - Shankumar Mooyottu
- Department of Veterinary Pathology, Iowa State University, Ames, IA, USA
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12
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Bryant AE, Gomi S, Katahira E, Huang DB, Stevens DL. The effects of iclaprim on exotoxin production in methicillin-resistant and vancomycin-intermediate Staphylococcus aureus. J Med Microbiol 2019; 68:456-466. [PMID: 30676310 DOI: 10.1099/jmm.0.000929] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PURPOSE Extracellular protein toxins contribute to the pathogenesis of Staphylococcus aureus infections. The present study compared the effects of iclaprim and trimethoprim - two folic acid synthesis inhibitors - with nafcillin and vancomycin on production of Panton-Valentine leukocidin (PVL), alpha haemolysin (AH) and toxic-shock syndrome toxin I (TSST-1) in methicillin-resistant and vancomycin-intermediate S. aureus (MRSA and VISA, respectively). METHODOLOGY Northern blotting and RT-PCR were used to assess gene transcription; toxin-specific bioassays were used to measure protein toxin production. RESULTS As shown previously, sub-inhibitory concentrations (sub-MIC) of nafcillin increased and prolonged MRSA toxin gene transcription and enhanced PVL, TSST-1 and AH production. Sub-inhibitory doses of iclaprim and trimethoprim delayed maximal AH gene (hla) transcription and suppressed AH production; both drugs delayed, but neither reduced, maximal TSST-1 production. Trimethoprim significantly increased lukF-PV expression and PVL production compared to both untreated and iclaprim-treated cultures. Higher concentrations of iclaprim and trimethoprim markedly suppressed MRSA growth, mRNA synthesis and toxin production. In VISA, iclaprim, vancomycin and nafcillin variably increased tst and hla expression, but only nafcillin increased toxin production. Despite its ability to increase hla expression, iclaprim was the most potent inhibitor of AH production. CONCLUSIONS We conclude that, due to its ability to suppress toxin production, iclaprim should be effective against severe staphylococcal infections caused by toxin-producing MRSA and VISA strains, especially given its ability to concentrate at sites of infection such as skin and skin structures and the lung.
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Affiliation(s)
- Amy E Bryant
- 1 University of Washington School of Medicine, Seattle, WA, USA
| | - Sumiko Gomi
- 2 Veterans Affairs Medical Center, Boise, ID, USA
| | - Eva Katahira
- 2 Veterans Affairs Medical Center, Boise, ID, USA
| | | | - Dennis L Stevens
- 1 University of Washington School of Medicine, Seattle, WA, USA
- 2 Veterans Affairs Medical Center, Boise, ID, USA
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13
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Yang J, Yang H. Effect of Bifidobacterium breve in Combination With Different Antibiotics on Clostridium difficile. Front Microbiol 2018; 9:2953. [PMID: 30564210 PMCID: PMC6288195 DOI: 10.3389/fmicb.2018.02953] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 11/16/2018] [Indexed: 12/18/2022] Open
Abstract
While combinations of probiotics with antibiotics have exhibited beneficial and adverse effects in the treatment of Clostridium difficile infection (CDI), no substantive explanation has been provided for these effects. In this study, C. difficile ATCC 9689 (CD) was treated with Bifidobacterium breve (YH68) in combination with five different antibiotics to explore the effects of the different combinations on C. difficile. Cell-free culture supernatant (CFCS) of YH68 was combined with metronidazole (MTR), vancomycin (VAN), clindamycin (CLI), ceftazidime (CAZ) or ampicillin (AMP) to treat CD. The plate counting method was used to determine the growth and spore production of CD, and cell damage was assessed by the measurement of extracellular ATP levels with a luminescence-based kit. The production of toxin A/B was measured with an ELISA kit. The gene expression levels of tcdA and tcdB in CD were evaluated by real-time qPCR. The CFCS of YH68 (3 × 109 CFU/mL) at 0.25 times the minimal inhibitory concentration (MIC) (0.25YH68) in combination with the five antibiotics exerted stronger inhibitory effects on the growth and spore production of CD than the same antibiotics in the absence of 0.25YH68, except 0.25YH68&MTR&, 0.25YH68&MTR&CAZ, and 0.25YH68&VAN&CLI. However, treatment with 0.25YH68&VAN, 0.25YH68&, 0.25YH68&MTR&CAZ, 0.25YH68&VAN&CAZ, 0.25YH68&VAN&, and 0.25YH68&CAZ& resulted in increased cell damage. In addition, the different combinations, except 0.25YH68&CLI, 0.25YH68&MTR& and 0.25YH68&VAN&CLI, dramatically reduced the production of toxin A/B in comparison with the effects of the same antibiotics in the absence of 0.25YH68. The gene expression levels of tcdA and tcdB in CD were lowered upon treatment with 0.25YH68 in combination with MTR, CLI, CAZ, MTR&CAZ, MTR&, CLI&CAZ, and CLI&, whereas the levels were enhanced by 0.25YH68 in combination with VAN, AMP, MTR&CLI, VAN&CLI, VAN&, and CAZ&. In summary, YH68 in combination with specific antibiotics could enhance the inhibitory effects of antibiotics against CD. In addition, the antagonistic effects between some antibiotics could be weakened by YH68.
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Affiliation(s)
| | - Hong Yang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Aldape MJ, Rice SN, Field KP, Bryant AE, Stevens DL. Sub-lethal doses of surotomycin and vancomycin have similar effects on Clostridium difficile virulence factor production in vitro. J Med Microbiol 2018; 67:1689-1697. [PMID: 30307842 DOI: 10.1099/jmm.0.000852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
PURPOSE Clostridium difficile is an anaerobic spore-forming bacterial pathogen that causes a spectrum of illness severity ranging from mild diarrhoea to severe life-threatening pseudomembranous colitis. C. difficile infection (CDI) is antibiotic-associated and primarily mediated by two exotoxins, Toxins A and B. We and others have shown that some antibiotics stimulate Toxin A and B production by C. difficile in a strain-specific manner. Still, the effects of newer anti-C. difficile antibiotics on this process and spore formation remain to be investigated. METHODOLOGY Surotomycin (formally CB-183,315) is a novel, minimally absorbed, narrow-spectrum antibiotic. We determined the effects of surotomycin on C. difficile growth, toxin production and sporulation in historical and BI/NAP1/027 epidemic strains of C. difficile.Results/Key findings. While antibiotic free controls showed toxin production during the stationary phase growth, all strains exposed to sub-inhibitory concentrations of surotomycin and vancomycin demonstrated increased TcdA and TcdB production during early (log phase) growth by all strains. However, this effect was not observed at 24 or 48 h post-treatment by any of the C. difficile strains exposed to either antibiotic. Additionally, all doses of surotomycin and vancomycin suppressed spore formation in all tested strains. CONCLUSION In summary, these findings demonstrate that surotomycin and vancomycin have similar effects on exotoxin production and sporulation by C. difficile in vitro. Furthermore, since spores contribute to recurrent infection, the ability of surotomycin to suppress spore formation may explain its ability to disrupt the reinfection cycle in the clinical setting.
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Affiliation(s)
- Michael John Aldape
- 1Department of Veterans Affairs Medical Center, Department of Veterans Affairs Medical Center, Boise, ID, USA
| | - Savannah Nicole Rice
- 1Department of Veterans Affairs Medical Center, Department of Veterans Affairs Medical Center, Boise, ID, USA
| | - Kevin Patrick Field
- 1Department of Veterans Affairs Medical Center, Department of Veterans Affairs Medical Center, Boise, ID, USA
| | - Amy Evelyn Bryant
- 1Department of Veterans Affairs Medical Center, Department of Veterans Affairs Medical Center, Boise, ID, USA.,2University of Washington School of Medicine, Seattle, WA, USA
| | - Dennis Leroy Stevens
- 1Department of Veterans Affairs Medical Center, Department of Veterans Affairs Medical Center, Boise, ID, USA.,2University of Washington School of Medicine, Seattle, WA, USA
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Aldape MJ, Bayer CR, Rice SN, Bryant AE, Stevens DL. Comparative efficacy of antibiotics in treating experimental Clostridium septicum infection. Int J Antimicrob Agents 2018; 52:469-473. [PMID: 30012441 DOI: 10.1016/j.ijantimicag.2018.07.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/07/2018] [Indexed: 02/03/2023]
Abstract
Clostridium septicum is a highly pathogenic microbe that causes gas gangrene in humans, and is the principal cause of spontaneous gas gangrene in patients with gastrointestinal maladies, including adenocarcinoma of the colon. Despite modern approaches to manage C. septicum infection, morbidity and mortality remain high (>60%). At present, no objective in-vivo data exist supporting the current antibiotic treatment recommendations for C. septicum infection. Utilizing an established murine model of clostridial myonecrosis, this study investigated the efficacy of standard antibiotics for anaerobic Gram-positive soft tissue infections (penicillin, clindamycin, tetracycline and vancomycin) in treating C. septicum gas gangrene. Following intramuscular challenge with 1 × 106 colony-forming units of C. septicum, antibiotics were administered by intraperitoneal injection every 4 h for a total of four doses. At 30 h, all animals in all treatment groups survived the C. septicum challenge, compared with no survivors in the untreated controls (100% mortality by 10 h). However, by 60 h, mice treated with vancomycin exhibited 40% mortality, with no mortality observed in any other antibiotic treatment group. Microbroth dilution minimum inhibitory concentration analyses for three strains of C. septicum also demonstrated high susceptibility to penicillin, clindamycin and tetracycline, but considerably lower susceptibility to vancomycin. This study suggests that penicillin, clindamycin and tetracycline are suitable alternatives for the treatment of C. septicum infection in humans.
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Affiliation(s)
| | | | | | - Amy Evelyn Bryant
- Department of Veterans Affairs Medical Center, Boise, ID, USA; University of Washington School of Medicine, Seattle, WA, USA
| | - Dennis Leroy Stevens
- Department of Veterans Affairs Medical Center, Boise, ID, USA; University of Washington School of Medicine, Seattle, WA, USA
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Chandrasekaran R, Lacy DB. The role of toxins in Clostridium difficile infection. FEMS Microbiol Rev 2017; 41:723-750. [PMID: 29048477 PMCID: PMC5812492 DOI: 10.1093/femsre/fux048] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 10/10/2017] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile is a bacterial pathogen that is the leading cause of nosocomial antibiotic-associated diarrhea and pseudomembranous colitis worldwide. The incidence, severity, mortality and healthcare costs associated with C. difficile infection (CDI) are rising, making C. difficile a major threat to public health. Traditional treatments for CDI involve use of antibiotics such as metronidazole and vancomycin, but disease recurrence occurs in about 30% of patients, highlighting the need for new therapies. The pathogenesis of C. difficile is primarily mediated by the actions of two large clostridial glucosylating toxins, toxin A (TcdA) and toxin B (TcdB). Some strains produce a third toxin, the binary toxin C. difficile transferase, which can also contribute to C. difficile virulence and disease. These toxins act on the colonic epithelium and immune cells and induce a complex cascade of cellular events that result in fluid secretion, inflammation and tissue damage, which are the hallmark features of the disease. In this review, we summarize our current understanding of the structure and mechanism of action of the C. difficile toxins and their role in disease.
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Affiliation(s)
- Ramyavardhanee Chandrasekaran
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - D. Borden Lacy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- The Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37232, USA
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Aldape MJ, Packham AE, Heeney DD, Rice SN, Bryant AE, Stevens DL. Fidaxomicin reduces early toxin A and B production and sporulation in Clostridium difficile
in vitro. J Med Microbiol 2017; 66:1393-1399. [DOI: 10.1099/jmm.0.000580] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Michael J. Aldape
- Department of Veterans Affairs Medical Center, 500 W. Fort St, Boise, ID 83712, USA
| | - Aaron E. Packham
- Department of Veterans Affairs Medical Center, 500 W. Fort St, Boise, ID 83712, USA
- Present address: Kirksville College of Osteopathic Medicine, Kirksville, MO, USA
| | - Dustin D. Heeney
- Department of Veterans Affairs Medical Center, 500 W. Fort St, Boise, ID 83712, USA
- Present address: The University of California, Davis, CA, USA
| | - Savannah N. Rice
- Department of Veterans Affairs Medical Center, 500 W. Fort St, Boise, ID 83712, USA
| | - Amy E. Bryant
- Department of Veterans Affairs Medical Center, 500 W. Fort St, Boise, ID 83712, USA
- University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA 98195, USA
| | - Dennis L. Stevens
- Department of Veterans Affairs Medical Center, 500 W. Fort St, Boise, ID 83712, USA
- University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA 98195, USA
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18
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Zarandi ER, Mansouri S, Nakhaee N, Sarafzadeh F, Moradi M. Toxin production of Clostridium difficile in sub-MIC of vancomycin and clindamycin alone and in combination with ceftazidime. Microb Pathog 2017; 107:249-253. [PMID: 28286152 DOI: 10.1016/j.micpath.2017.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 02/26/2017] [Accepted: 03/06/2017] [Indexed: 02/01/2023]
Abstract
Toxin production in Clostridium difficile (C. difficile) is a key process for induction of diarrhea. Several factors such as sub-MIC of antibiotics impact on toxin production. The aim of this research is investigation of sub-minimum inhibitory concentration (sub-MIC) of vancomycin (VAN), clindamycin (CLI) separately and in combination with ceftazidime (CAZ) on toxin production in C. difficile. About ∼106 colony forming units (CFU) from 18-h culture of C. difficile ATCC 9689 and clinical isolates A+/B+/CTD-, were cultured anaerobically in the pre-reduced medium with appropriate concentration of separated and in combination antibiotics. After 24 and 48 h, 1 mL of culture was removed, centrifuged and the supernatant stored at-70 °C for later use. The evaluation of toxin production was carried out by the ELISA technique. All antibiotics alone and in combination formats inhibited toxin production over a period of 24 h. This effect is also observed in presence of VAN and CLI during a period of 48 h. Over a 4 h period, CAZ increased toxin production alone and in combination, especially with CLI. The data showed VAN and CLI decrease the level of toxins. In contrast, the CAZ not only increases the level of produced toxin, but also can interfere with VAN and CLI. Based on the results, combination therapy which is performed for treatment or prevention of other infections may cause toxin production and probably the severity of C. difficile AAD to increase.
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Affiliation(s)
- Ebrahim Rezazadeh Zarandi
- Department of Microbiology and Virology, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Shahla Mansouri
- Department of Microbiology and Virology, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Nouzar Nakhaee
- Department of Community Medicine, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Farhad Sarafzadeh
- Department of Infectious Diseases, Afzalipour Hospital, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Moradi
- Department of Microbiology and Virology, Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
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Martin-Verstraete I, Peltier J, Dupuy B. The Regulatory Networks That Control Clostridium difficile Toxin Synthesis. Toxins (Basel) 2016; 8:E153. [PMID: 27187475 PMCID: PMC4885068 DOI: 10.3390/toxins8050153] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/03/2016] [Accepted: 05/05/2016] [Indexed: 12/19/2022] Open
Abstract
The pathogenic clostridia cause many human and animal diseases, which typically arise as a consequence of the production of potent exotoxins. Among the enterotoxic clostridia, Clostridium difficile is the main causative agent of nosocomial intestinal infections in adults with a compromised gut microbiota caused by antibiotic treatment. The symptoms of C. difficile infection are essentially caused by the production of two exotoxins: TcdA and TcdB. Moreover, for severe forms of disease, the spectrum of diseases caused by C. difficile has also been correlated to the levels of toxins that are produced during host infection. This observation strengthened the idea that the regulation of toxin synthesis is an important part of C. difficile pathogenesis. This review summarizes our current knowledge about the regulators and sigma factors that have been reported to control toxin gene expression in response to several environmental signals and stresses, including the availability of certain carbon sources and amino acids, or to signaling molecules, such as the autoinducing peptides of quorum sensing systems. The overlapping regulation of key metabolic pathways and toxin synthesis strongly suggests that toxin production is a complex response that is triggered by bacteria in response to particular states of nutrient availability during infection.
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Affiliation(s)
- Isabelle Martin-Verstraete
- Laboratoire Pathogenèse des Bactéries Anaérobes, Department of Microbiology, Institut Pasteur, 25 rue du Dr Roux Paris, Paris 75015, France.
- UFR Sciences du vivant, University Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris 75015, France.
| | - Johann Peltier
- Laboratoire Pathogenèse des Bactéries Anaérobes, Department of Microbiology, Institut Pasteur, 25 rue du Dr Roux Paris, Paris 75015, France.
| | - Bruno Dupuy
- Laboratoire Pathogenèse des Bactéries Anaérobes, Department of Microbiology, Institut Pasteur, 25 rue du Dr Roux Paris, Paris 75015, France.
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Abstract
Infection of the colon with the Gram-positive bacterium Clostridium difficile is potentially life threatening, especially in elderly people and in patients who have dysbiosis of the gut microbiota following antimicrobial drug exposure. C. difficile is the leading cause of health-care-associated infective diarrhoea. The life cycle of C. difficile is influenced by antimicrobial agents, the host immune system, and the host microbiota and its associated metabolites. The primary mediators of inflammation in C. difficile infection (CDI) are large clostridial toxins, toxin A (TcdA) and toxin B (TcdB), and, in some bacterial strains, the binary toxin CDT. The toxins trigger a complex cascade of host cellular responses to cause diarrhoea, inflammation and tissue necrosis - the major symptoms of CDI. The factors responsible for the epidemic of some C. difficile strains are poorly understood. Recurrent infections are common and can be debilitating. Toxin detection for diagnosis is important for accurate epidemiological study, and for optimal management and prevention strategies. Infections are commonly treated with specific antimicrobial agents, but faecal microbiota transplants have shown promise for recurrent infections. Future biotherapies for C. difficile infections are likely to involve defined combinations of key gut microbiota.
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Affiliation(s)
- Wiep Klaas Smits
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, and Department of Microbiology, Monash University, Victoria, Australia
| | - D. Borden Lacy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, and The Veterans Affairs Tennessee Valley Healthcare System, Nashville Tennessee, USA
| | - Mark H. Wilcox
- Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Ed J. Kuijper
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
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The SOS Response Master Regulator LexA Is Associated with Sporulation, Motility and Biofilm Formation in Clostridium difficile. PLoS One 2015; 10:e0144763. [PMID: 26682547 PMCID: PMC4689574 DOI: 10.1371/journal.pone.0144763] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/22/2015] [Indexed: 01/05/2023] Open
Abstract
The LexA regulated SOS network is a bacterial response to DNA damage of metabolic or environmental origin. In Clostridium difficile, a nosocomial pathogen causing a range of intestinal diseases, the in-silico deduced LexA network included the core SOS genes involved in the DNA repair and genes involved in various other biological functions that vary among different ribotypes. Here we describe the construction and characterization of a lexA ClosTron mutant in C. difficile R20291 strain. The mutation of lexA caused inhibition of cell division resulting in a filamentous phenotype. The lexA mutant also showed decreased sporulation, a reduction in swimming motility, greater sensitivity to metronidazole, and increased biofilm formation. Changes in the regulation of toxin A, but not toxin B, were observed in the lexA mutant in the presence of sub-inhibitory concentrations of levofloxacin. C. difficile LexA is, therefore, not only a regulator of DNA damage but also controls many biological functions associated with virulence.
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Effects of fluoroquinolone restriction (from 2007 to 2012) on Clostridium difficile infections: interrupted time-series analysis. J Hosp Infect 2015; 91:74-80. [PMID: 26169793 DOI: 10.1016/j.jhin.2015.05.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 05/08/2015] [Indexed: 11/20/2022]
Abstract
BACKGROUND Antimicrobial stewardship is a key component in the reduction of healthcare-associated infections, particularly Clostridium difficile infection (CDI). We successfully restricted the use of cephalosporins and, subsequently, fluoroquinolones. From an endemically high level of >280 cases per year in 2007-08, the number of CDIs reduced to 72 cases in 2011-12. AIM To describe the implementation and impact of fluoroquinolone restriction on CDI. METHODS This was an interrupted time-series analysis pre and post fluoroquinolone restriction for 60 months based on a Poisson distribution model. FINDINGS In June 2008, fluoroquinolone consumption halved to about 5 defined daily doses (DDD) per 100 occupied bed-days (OBD). This was followed by a significant fall in CDI number [rate ratio (RR): 0.332; 95% confidence interval (CI): 0.240-0.460] which remained low over the subsequent months. Subsequently, fluoroquinolone consumption was further reduced to about 2 DDD/100 OBD in June 2010 accompanied by further reduction in CDI rate (RR: 0.394; 95% CI: 0.199-0.781). In a univariate Poisson model the CDI rate was associated with fluoroquinolone usage (RR: 1.086; 95% CI: 1.077-1.094). CONCLUSION We conclude that in an environment where cephalosporin usage is already low, the reduction in fluoroquinolone usage was associated with an immediate, large, and significant reduction in CDI cases.
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Global Phenotypic Characterization of Effects of Fluoroquinolone Resistance Selection on the Metabolic Activities and Drug Susceptibilities of Clostridium perfringens Strains. Int J Microbiol 2014; 2014:456979. [PMID: 25587280 PMCID: PMC4283427 DOI: 10.1155/2014/456979] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 11/07/2014] [Accepted: 11/10/2014] [Indexed: 12/29/2022] Open
Abstract
Fluoroquinolone resistance affects toxin production of Clostridium perfringens strains differently. To investigate the effect of fluoroquinolone resistance selection on global changes in metabolic activities and drug susceptibilities, four C. perfringens strains and their norfloxacin-, ciprofloxacin-, and gatifloxacin-resistant mutants were compared in nearly 2000 assays, using phenotype microarray plates. Variations among mutant strains resulting from resistance selection were observed in all aspects of metabolism. Carbon utilization, pH range, osmotic tolerance, and chemical sensitivity of resistant strains were affected differently in the resistant mutants depending on both the bacterial genotype and the fluoroquinolone to which the bacterium was resistant. The susceptibilities to gentamicin and erythromycin of all resistant mutants except one increased, but some resistant strains were less susceptible to amoxicillin, cefoxitin, ceftriaxone, chloramphenicol, and metronidazole than their wild types. Sensitivity to ethidium bromide decreased in some resistant mutants and increased in others. Microarray analysis of two gatifloxacin-resistant mutants showed changes in metabolic activities that were correlated with altered expression of various genes. Both the chemical structures of fluoroquinolones and the genomic makeup of the wild types influenced the changes found in resistant mutants, which may explain some inconsistent reports of the effects of therapeutic use of fluoroquinolones on clinical isolates of bacteria.
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Aldape MJ, Heeney DD, Bryant AE, Stevens DL. Tigecycline suppresses toxin A and B production and sporulation in Clostridium difficile. J Antimicrob Chemother 2014; 70:153-9. [PMID: 25151204 DOI: 10.1093/jac/dku325] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Clostridium difficile infection (CDI) is mediated by potent extracellular toxins and is spread largely via bacterial spores. We and others have shown that some antibiotics stimulate C. difficile toxin production in a strain-specific manner; however, the effects of newer anti-C. difficile antibiotics on this process remain to be investigated. METHODS The effects of the protein synthesis inhibitor tigecycline on sporulation and toxin A and toxin B production were compared in historical (strain 9689) and hypervirulent BI/NAP1/027 (strain 5325) isolates of C. difficile in vitro. RESULTS Tigecycline at 1/4× MIC stimulated an increased and earlier toxin A and/or B gene expression in both the historical and the hypervirulent strains, although a commensurate increase in toxin protein production was observed only in the 9689 strain. In fact, in the hypervirulent 5325 strain, toxin production was dramatically suppressed. By comparison, subinhibitory concentrations of vancomycin and metronidazole also stimulated increased protein toxin production by the historical, but not the hypervirulent, strain. In addition, tigecycline dose-dependently reduced viable spore production by both the 9689 and 5325 strains. Vancomycin treatment also suppressed spore formation in both C. difficile strains; however, metronidazole, while reducing spore formation in the 9689 strain, stimulated a near 2 log increase in spore production by the 5325 isolate. CONCLUSIONS In summary, these findings suggest that the treatment of CDI patients with tigecycline could effectively both control disease progression and limit its spread by disrupting sporulation.
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Affiliation(s)
- Michael John Aldape
- Department of Veterans Affairs Medical Center, 500 W. Fort Street, Boise, ID 83702, USA
| | - Dustin Delaney Heeney
- Department of Veterans Affairs Medical Center, 500 W. Fort Street, Boise, ID 83702, USA
| | - Amy Evelyn Bryant
- Department of Veterans Affairs Medical Center, 500 W. Fort Street, Boise, ID 83702, USA University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Dennis Leroy Stevens
- Department of Veterans Affairs Medical Center, 500 W. Fort Street, Boise, ID 83702, USA University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA 98195, USA
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Synergistic effects of antimicrobial peptides and antibiotics against Clostridium difficile. Antimicrob Agents Chemother 2014; 58:5719-25. [PMID: 25022581 DOI: 10.1128/aac.02542-14] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Accelerating rates of health care-associated infections caused by Clostridium difficile, with increasing recurrence and rising antibiotic resistance rates, have become a serious problem in recent years. This study was conducted to explore whether a combination of antibiotics with human antimicrobial peptides may lead to an increase in antibacterial activity. The in vitro activities of the antimicrobial peptides HBD1 to HBD3, HNP1, HD5, and LL-37 and the antibiotics tigecycline, moxifloxacin, piperacillin-tazobactam, and meropenem alone or in combination against 10 toxinogenic and 10 nontoxinogenic C. difficile strains were investigated. Bacterial viability was determined by flow cytometry and toxin production by enzyme-linked immunosorbent assay (ELISA). When combined at subinhibitory concentrations, antimicrobial peptides and antibiotics generally led to an additive killing effect against toxinogenic and nontoxinogenic C. difficile strains. However, LL-37 and HBD3 acted in synergism with all the antibiotics that were tested. Electron microscopy revealed membrane perturbation in bacterial cell walls by HBD3. In 3 out of 10 toxinogenic strains, HBD3, LL-37, piperacillin-tazobactam, and meropenem administration led to an increased toxin release which was not neutralized by the addition of HNP1. Antimicrobial peptides increase the bacterial killing of antibiotics against C. difficile regardless of the antibiotics' mode of action. Membrane perturbation in or pore formation on the bacterial cell wall may enhance the uptake of antibiotics and increase their antibacterial effect. Therefore, a combination of antibiotics with antimicrobial peptides may represent a promising novel approach to the treatment of C. difficile infections.
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Zboromyrska Y, Hurtado JC, Salvador P, Alvarez-Martínez MJ, Valls ME, Mas J, Marcos MA, Gascón J, Vila J. Aetiology of traveller's diarrhoea: evaluation of a multiplex PCR tool to detect different enteropathogens. Clin Microbiol Infect 2014; 20:O753-9. [PMID: 24621195 DOI: 10.1111/1469-0691.12621] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 12/13/2022]
Abstract
Traveller's diarrhoea (TD) is the most common illness reported in international travellers. TD is caused by a wide range of pathogens, including bacteria, viruses and parasites. Multiplex PCR assays can be especially useful for studying the aetiology of TD. The first objective of this study was to evaluate the utility of the commercially available multiplex PCR (xTAG(®) Gastrointestinal Pathogen Panel (GPP)) for the diagnosis of TD. A total of 185 stool specimens obtained from 174 patients were processed using the GPP assay. This test detected 86 pathogens in 67 stool samples (67/185, 36.2%). Sixteen pathogens out of 86 were also detected by routine testing. The remaining pathogens (n = 70) required further confirmation by alternative techniques. Finally, 60 out of 70 pathogens were confirmed. The second objective of this study was to analyse the aetiology of TD based on the results obtained by the GPP test and routine methods. The primary pathogens causing TD were Shigella (24.2%) followed by enterotoxigenic Escherichia coli (ETEC) (23.2%), enteroaggregative E. coli (14.7%) and Giardia (13.7%). Significant regional differences were observed for ETEC with 19.4% of TD cases acquired in Africa, 11.3% in Asia and none in South Central (SC) America (p 0.01), Giardia was found in 1.5% of cases among those who had travelled to Africa, 14.1% of those who had travelled to Asia and 3% of those who had travelled to SC America (p 0.01). In conclusion, the GPP test improved the detection of enteropathogens and allowed better assessment of the aetiology of TD.
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Affiliation(s)
- Y Zboromyrska
- Department of Clinical Microbiology, Hospital Clínic, School of Medicine, University of Barcelona, Barcelona, Spain
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The LexA regulated genes of the Clostridium difficile. BMC Microbiol 2014; 14:88. [PMID: 24713082 PMCID: PMC4234289 DOI: 10.1186/1471-2180-14-88] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 03/27/2014] [Indexed: 01/05/2023] Open
Abstract
Background The SOS response including two main proteins LexA and RecA, maintains the integrity of bacterial genomes after DNA damage due to metabolic or environmental assaults. Additionally, derepression of LexA-regulated genes can result in mutations, genetic exchange and expression of virulence factors. Here we describe the first comprehensive description of the in silico LexA regulon in Clostridium difficile, an important human pathogen. Results We grouped thirty C. difficile strains from different ribotypes and toxinotypes into three clusters according to lexA gene/protein variability. We applied in silico analysis coupled to surface plasmon resonance spectroscopy (SPR) and determined 16 LexA binding sites in C. difficile. Our data indicate that strains within the cluster, as defined by LexA variability, harbour several specific LexA regulon genes. In addition to core SOS genes: lexA, recA, ruvCA and uvrBA, we identified a LexA binding site on the pathogenicity locus (PaLoc) and in the putative promoter region of several genes involved in housekeeping, sporulation and antibiotic resistance. Conclusions Results presented here suggest that in C. difficile LexA is not merely a regulator of the DNA damage response genes but also controls the expression of dozen genes involved in various other biological functions. Our in vitro results indicate that in C. difficile inactivation of LexA repressor depends on repressor`s dissociation from the operators. We report that the repressor`s dissociation rates from operators differentiate, thus the determined LexA-DNA dissociation constants imply on the timing of SOS gene expression in C. difficile.
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29
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Leuzzi R, Adamo R, Scarselli M. Vaccines against Clostridium difficile. Hum Vaccin Immunother 2014; 10:1466-77. [PMID: 24637887 DOI: 10.4161/hv.28428] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Clostridium difficile infection (CDI) is recognized as a major cause of nosocomial diseases ranging from antibiotic related diarrhea to fulminant colitis. Emergence during the last 2 decades of C. difficile strains associated with high incidence, severity and lethal outcomes has increased the challenges for CDI treatment. A limited number of drugs have proven to be effective against CDI and concerns about antibiotic resistance as well as recurring disease solicited the search for novel therapeutic strategies. Active vaccination provides the attractive opportunity to prevent CDI, and intense research in recent years led to development of experimental vaccines, 3 of which are currently under clinical evaluation. This review summarizes recent achievements and remaining challenges in the field of C. difficile vaccines, and discusses future perspectives in view of newly-identified candidate antigens.
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30
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Garneau JR, Valiquette L, Fortier LC. Prevention of Clostridium difficile spore formation by sub-inhibitory concentrations of tigecycline and piperacillin/tazobactam. BMC Infect Dis 2014; 14:29. [PMID: 24422950 PMCID: PMC3897887 DOI: 10.1186/1471-2334-14-29] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 01/08/2014] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Sporulation of Clostridium difficile during infection and persistence of spores within the gut could partly explain treatment failures and recurrence. However, the influence of antibiotics on sporulation is unclear. The objective of our study was to evaluate the impact of ciprofloxacin, metronidazole, piperacillin/tazobactam, tigecycline, and vancomycin on C. difficile sporulation in vitro. METHODS The reference strains ATCC 9689, 630, VPI 10463, and seven other clinical isolates of C. difficile were used, including three epidemic NAP1/027 isolates. Minimum inhibitory concentrations (MIC) were determined and sporulation was assessed after growth in the absence or presence of ≤0.5x MIC concentrations of each antibiotic. RESULTS All strains were sensitive to the antibiotics tested, except ribotype 027 isolates that were resistant to ciprofloxacin (MIC = 128 mg/L). Metronidazole and vancomycin generally did not significantly affect spore production in C. difficile, although vancomycin slightly affected sporulation of a few isolates. Ciprofloxacin inhibited sporulation of ribotype 027 isolates mainly. Interestingly, sub-MIC concentrations of piperacillin/tazobactam reduced spore formation in several isolates. However, the most striking observation was made with tigecycline, with an important reduction of spore formation in most isolates. CONCLUSIONS The capacity of C. difficile to sporulate can be significantly affected by certain antibiotics. The reduced sporulation observed with tigecycline and piperacillin/tazobactam might explain why these antibiotics are generally associated with lower risk of C. difficile infections. In addition, the inhibition of sporulation might partly explain the apparent efficacy of tigecycline for treatment of patients with recurrent infection.
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Affiliation(s)
| | | | - Louis-Charles Fortier
- Département de microbiologie et d'infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3201 rue Jean Mignault, Sherbrooke, Québec J1E 4K8, Canada.
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Carter GP, Cheung JK, Larcombe S, Lyras D. Regulation of toxin production in the pathogenic clostridia. Mol Microbiol 2013; 91:221-31. [DOI: 10.1111/mmi.12469] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Glen P. Carter
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Jackie K. Cheung
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Sarah Larcombe
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Dena Lyras
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
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Abstract
Clostridium difficile infections (CDI) have emerged as a major cause of healthcare associated disease, and recent epidemiological evidence also suggests an important role in community-acquired diarrhea. This increase is associated with specific types, especially PCR ribotypes 027 and 078, which are sometimes referred to as “hypervirulent”. Over the past years major advances have been made in our understanding of C. difficile pathogenicity, with the identification and characterization of the major clostridial toxins TcdA and TcdB. However, the relation between the toxins, their regulation, and “hypervirulence” remain unclear. Here I review our current understanding of C. difficile pathogenicity and argue that “hypervirulent” is an inadequate term to describe PCR ribotypes 027 and 078, that the ability of C. difficile to cause problematic infections is a consequence of a multifactorial process that extends beyond toxins, sporulation, and antimicrobial resistance, and that vigilance is in order toward types that are closely related to ribotypes 027 and 078, but are currently not considered problematic.
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Affiliation(s)
- Wiep Klaas Smits
- Department of Medical Microbiology; Leiden University Medical Center; Leiden, the Netherlands
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