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Zhang S, Ma C, Zhang H, Zhao C, Guo R, Liu J, Wang J, Yuan J, Jia K, Wu A, Chen Y, Lei J. Toxin genotypes, antibiotic resistance and their correlations in Clostridioides difficile isolated from hospitals in Xi'an, China. BMC Microbiol 2024; 24:177. [PMID: 38783194 PMCID: PMC11112860 DOI: 10.1186/s12866-024-03327-z] [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: 04/13/2023] [Accepted: 05/10/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Clostridioides difficile is the main pathogen of antimicrobial-associated diarrhoea and health care facility-associated infectious diarrhoea. This study aimed to investigate the prevalence, toxin genotypes, and antibiotic resistance of C. difficile among hospitalized patients in Xi'an, China. RESULTS We isolated and cultured 156 strains of C. difficile, representing 12.67% of the 1231 inpatient stool samples collected. Among the isolates, tcdA + B + strains were predominant, accounting for 78.2% (122/156), followed by 27 tcdA-B + strains (27/156, 17.3%) and 6 binary toxin gene-positive strains. The positive rates of three regulatory genes, tcdC, tcdR, and tcdE, were 89.1% (139/156), 96.8% (151/156), and 100%, respectively. All isolates were sensitive to metronidazole, and the resistance rates to clindamycin and cephalosporins were also high. Six strains were found to be resistant to vancomycin. CONCLUSION Currently, the prevalence rate of C. difficile infection (CDI) in Xi'an is 12.67% (156/1231), with the major toxin genotype of the isolates being tcdA + tcdB + cdtA-/B-. Metronidazole and vancomycin were still effective drugs for the treatment of CDI, but we should pay attention to antibiotic management and epidemiological surveillance of CDI.
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Affiliation(s)
- Sukai Zhang
- Clinical Medicine Class of 2019, Xi'an Jiaotong University, Xi'an, China
| | - Chen Ma
- Department of Clinical Laboratory, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Haiyue Zhang
- Clinical Medicine Class of 2019, Xi'an Jiaotong University, Xi'an, China
| | - Congcong Zhao
- Clinical Medicine Class of 2019, Xi'an Jiaotong University, Xi'an, China
| | - Ruibing Guo
- Clinical Medicine Class of 2019, Xi'an Jiaotong University, Xi'an, China
| | - Jiahao Liu
- Clinical Medicine Class of 2019, Xi'an Jiaotong University, Xi'an, China
| | - Jing Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jing Yuan
- Department of Clinical Laboratory, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Kai Jia
- Xi'an Children's Hospital, Xi'an, China
| | | | - Yanjiong Chen
- Department of Immunology and Pathogenic Biology, College of Basic Medicine, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Jin'e Lei
- Department of Clinical Laboratory, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
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Pourliotopoulou E, Karampatakis T, Kachrimanidou M. Exploring the Toxin-Mediated Mechanisms in Clostridioides difficile Infection. Microorganisms 2024; 12:1004. [PMID: 38792835 PMCID: PMC11124097 DOI: 10.3390/microorganisms12051004] [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: 04/20/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Clostridioides difficile infection (CDI) is the leading cause of nosocomial antibiotic-associated diarrhea, and colitis, with increasing incidence and healthcare costs. Its pathogenesis is primarily driven by toxins produced by the bacterium C. difficile, Toxin A (TcdA) and Toxin B (TcdB). Certain strains produce an additional toxin, the C. difficile transferase (CDT), which further enhances the virulence and pathogenicity of C. difficile. These toxins disrupt colonic epithelial barrier integrity, and induce inflammation and cellular damage, leading to CDI symptoms. Significant progress has been made in the past decade in elucidating the molecular mechanisms of TcdA, TcdB, and CDT, which provide insights into the management of CDI and the future development of novel treatment strategies based on anti-toxin therapies. While antibiotics are common treatments, high recurrence rates necessitate alternative therapies. Bezlotoxumab, targeting TcdB, is the only available anti-toxin, yet limitations persist, prompting ongoing research. This review highlights the current knowledge of the structure and mechanism of action of C. difficile toxins and their role in disease. By comprehensively describing the toxin-mediated mechanisms, this review provides insights for the future development of novel treatment strategies and the management of CDI.
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Affiliation(s)
- Evdokia Pourliotopoulou
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
| | | | - Melania Kachrimanidou
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
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de-la-Rosa-Martinez D, Bobadilla Del Valle M, Esteban-Kenel V, Zinser Peniche P, Ponce De León Garduño A, Cornejo Juárez P, Sánchez Cruz MN, Camacho-Ortiz A, Vilar-Compte D. Molecular characterization and genotyping of isolates from cancer patients with Clostridioides difficile infection or asymptomatic colonization. J Med Microbiol 2023; 72. [PMID: 37624363 DOI: 10.1099/jmm.0.001748] [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] [Indexed: 08/26/2023] Open
Abstract
Introduction. Cancer patients with Clostridioides difficile infection (CDI) are at a higher risk for adverse outcomes. In addition, a high prevalence of Clostridioides difficile asymptomatic colonization (CDAC) has been reported in this vulnerable population.Gap Statement. The molecular characteristics and potential role of CDAC in healthcare-related transmission in the cancer population have been poorly explored.Aim. We aimed to compare the molecular and genotypic characteristics of C. difficile isolates from cancer patients with CDAC and CDI.Method. We conducted a prospective cohort study of cancer patients with CDAC or CDI from a referral centre. Molecular characterization, typification and tcdC gene expression of isolates were performed.Results. The hospital-onset and community-onset healthcare facility-associated CDI rates were 4.5 cases/10 000 patient-days and 1.4 cases/1 000 admissions during the study period. Fifty-one C. difficile strains were isolated: 37 (72 %) and 14 (28 %) from patients with CDI or CDAC, respectively. All isolates from symptomatic patients were tcdA+/tcdB+, and four (10 %) were ctdA+/ctdB+. In the CDAC group, 10 (71 %) isolates were toxigenic, and none were ctdA+/ctdB+. The Δ18 in-frame tcdC deletion and two transition mutations were found in five isolates. After bacterial typing, 60 % of toxigenic isolates from asymptomatic carriers were clonal to those from patients with C. difficile-associated diarrhoea. No NAP1/027/BI strains were detected.Conclusions. We found a clonal association between C. difficile isolates from patients with CDAC and CDI. Studies are needed to evaluate the potential role of asymptomatic carriers in the dynamics of nosocomial transmission to support infection control measures and reduce the burden of CDI in high-risk groups.
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Affiliation(s)
- Daniel de-la-Rosa-Martinez
- Plan de Estudios Combinados en Medicina (PECEM), Faculty of Medicine, Universidad Nacional Autonoma de Mexico, México City, Mexico
- Departament of Infectious Diseases, Instituto Nacional de Cancerología, Mexico City, Mexico
| | - Miriam Bobadilla Del Valle
- Laboratory of Clinical Microbiology, Departament of Infectious Diseases, Instituto Nacional de Ciencias Medicas y Nutrición, Mexico City, Mexico
| | - Veronica Esteban-Kenel
- Laboratory of Clinical Microbiology, Departament of Infectious Diseases, Instituto Nacional de Ciencias Medicas y Nutrición, Mexico City, Mexico
| | - Paola Zinser Peniche
- Departament of Infectious Diseases, Instituto Nacional de Cancerología, Mexico City, Mexico
| | - Alfredo Ponce De León Garduño
- Laboratory of Clinical Microbiology, Departament of Infectious Diseases, Instituto Nacional de Ciencias Medicas y Nutrición, Mexico City, Mexico
| | | | - María Nancy Sánchez Cruz
- Laboratory of Clinical Microbiology, Departament of Infectious Diseases, Instituto Nacional de Ciencias Medicas y Nutrición, Mexico City, Mexico
| | - Adrian Camacho-Ortiz
- Department of Infectious Diseases, Department of Internal Medicine, Hospital Universitario Dr. Jose Eleuterio Gonzalez, Universidad Autónoma de Nuevo León, Monterrey, Mexico
| | - Diana Vilar-Compte
- Departament of Infectious Diseases, Instituto Nacional de Cancerología, Mexico City, Mexico
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Ouyang Z, Zhao H, Zhao M, Yang Y, Zhao J. Type IV pili are involved in phenotypes associated with Clostridioides difficile pathogenesis. Crit Rev Microbiol 2023:1-9. [PMID: 37452617 DOI: 10.1080/1040841x.2023.2235002] [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: 03/13/2023] [Revised: 05/23/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023]
Abstract
Clostridioides difficile is a Gram-positive, spore-forming, rod-shaped, obligate anaerobe that is the leading cause of antibiotic-associated diarrhea. Type IV pili (T4P) are elongated appendages on the surface of C. difficile that are polymerized from many pilin proteins. T4P play an important role in C. difficile adherence and particularly in its persistence in the host intestine. Recent studies have shown that T4P promote C. difficile aggregation, surface motility, and biofilm formation, which may enhance its pathogenicity. Additionally, the second messenger cyclic diguanylate increases pilA1 transcript abundance, indirectly promoting T4P-mediated aggregation, surface motility, and biofilm formation of C. difficile. This review summarizes recent advances in C. difficile T4P research and the physiological activities of T4P in the context of C. difficile pathogenesis.
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Affiliation(s)
- Zirou Ouyang
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang City, Hebei Province, China
| | - Hanlin Zhao
- Department of Medical Laboratory, Hebei North University, Zhangjiakou, Hebei Province, China
| | - Min Zhao
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang City, Hebei Province, China
| | - Yaxuan Yang
- School of Public Health, The University of Queensland, Brisbane, Queensland, Australia
| | - Jianhong Zhao
- Hebei Provincial Center for Clinical Laboratories, The Second Hospital of Hebei Medical University, Shijiazhuang City, Hebei Province, China
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Ansarian Barezi A, Shakerian A, Rahimi E, Esfandiari Z. Examining the Extent of Contamination, Antibiotic Resistance, and Genetic Diversity of Clostridioides ( Clostridium) difficile Strains in Meat and Feces of Some Native Birds of Iran. BIOMED RESEARCH INTERNATIONAL 2023; 2023:3524091. [PMID: 37101693 PMCID: PMC10125756 DOI: 10.1155/2023/3524091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 12/25/2022] [Accepted: 01/21/2023] [Indexed: 04/28/2023]
Abstract
Clostridioides (Clostridium) difficile (C. difficile) is one of the essential enteropathogens in humans and livestock and is a severe health threat, according to the Centre for Disease Control and Prevention. Also, antimicrobials are one of the most critical risk factors for C. difficile infection (CDI). The present study examined the infection, antibiotic resistance, and genetic diversity of the C. difficile strains in the meat and feces of some native birds (chicken, duck, quail, and partridge) in the Shahrekord region, Iran, from July 2018 to July 2019. Samples were grown on CDMN agar after an enrichment step. To determine the toxin profile, the tcdA, tcdB, tcdC, cdtA, and cdtB genes were detected via multiplex PCR. The antibiotic susceptibility of these isolates was examined using the disk diffusion method and followed based on MIC and epsilometric test. 300 meat samples of chicken, duck, partridge, and quail and 1100 samples of bird feces were collected from six traditional farms in Shahrekord, Iran. Thirty-five meat samples (11.6%) and 191 fecal samples (17.36%) contained C. difficile. Moreover, five toxigenic samples isolated had 5, 1, and 3 tcdA/B, tcdC, and cdtA/B genes. Out of the studied strains isolated from the 226 samples, two isolates belonging to ribotype RT027 and one isolated RT078 profile related to native chicken feces were observed from chicken sample. The antimicrobial susceptibility testing showed that all the strains are resistant to ampicillin, 28.57% are resistant to metronidazole, and 100% were susceptible to vancomycin. Based on the results, it can be concluded that the raw meat of birds might be a source of resistant C. difficile that poses a hygienic threat to the consumption of native bird meat. Nevertheless, further studies are essential to understand additional epidemiological features of C. difficile in bird meat.
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Affiliation(s)
- Akbar Ansarian Barezi
- Department of Food Hygiene, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Amir Shakerian
- Research Center of Nutrition and Organic Products (R.C.N.O.P), Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Ebrahim Rahimi
- Department of Food Hygiene, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Zahra Esfandiari
- Nutrition and Food Security Research Center, Department of Food Science and Technology, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran
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Characterization of the virulence of three novel clade 2 Clostridioides (Clostridium) difficile strains and a two-year screening in animals and humans in Brazil. PLoS One 2022; 17:e0273013. [PMID: 36026500 PMCID: PMC9416996 DOI: 10.1371/journal.pone.0273013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/29/2022] [Indexed: 11/19/2022] Open
Abstract
Clostridioides (Clostridium) difficile infection (CDI) is an evolving global healthcare problem, and owing to the diverse and dynamic molecular epidemiology of C. difficile, new strains continue to emerge. In Brazil, only two cases of CDI due to the so called hypervirulent PCR ribotype (RT) 027 belonging to clade 2 have ever been reported, whereas incidence of CDI due to another “hypervirulent” RT078 (clade 5) has not yet been reported. In contrast, novel clade 2 strains have been identified in different hospitals. To better understand the epidemiology of CDIs in Brazil, this study aimed to genotypically and phenotypically characterize three novel Brazilian clade 2 strains (RT883, 884, and 885) isolated from patients with confirmed CDI. In addition, to better understand the circulating RTs, a two-year sampling was conducted in patients from the same hospital and in several domestic and wild animal species. The three strains examined showed lower production of A/B toxins than the control RT027, although two of these strains harbored a truncated tcdC gene. All strains showed swimming motility similar to that of RT027, while RT883 showed higher spore production than the reference strain. In the in vivo hamster model, the lethality of all strains was found to be similar to that of RT027. Both cgMLST and cgMLSA analyses revealed a high genetic similarity among the three-novel clade 2 isolates. In the two-year survey in animals and humans, RT883, 884, and 885 were not detected; however, three new RTs (RT988, RT989, and RT990) were isolated, two of which were genetically related to the three previously reported clade 2 strains. RT106 and RT126 were most frequently detected in humans (47.9%) and animals (57.9%), respectively. Furthermore, RT027 and RT078 were not detected in humans. The results of this study suggest that these novel clade 2 strains have virulence potential and that new strains from clade 2 continue to emerge in our setting, indicating the need for long-term local surveillance.
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Zhu D, Patabendige HMLW, Tomlinson BR, Wang S, Hussain S, Flores D, He Y, Shaw LN, Sun X. Cwl0971, a novel peptidoglycan hydrolase, plays pleiotropic roles in Clostridioides difficile R20291. Environ Microbiol 2021; 23:5222-5238. [PMID: 33893759 PMCID: PMC11217927 DOI: 10.1111/1462-2920.15529] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 04/12/2021] [Indexed: 02/04/2023]
Abstract
Clostridioides difficile is a Gram-positive, spore-forming, toxin-producing anaerobe that can cause nosocomial antibiotic-associated intestinal disease. Although the production of toxin A (TcdA) and toxin B (TcdB) contribute to the main pathogenesis of C. difficile, the mechanism of TcdA and TcdB release from cell remains unclear. In this study, we identified and characterized a new cell wall hydrolase Cwl0971 (CDR20291_0971) from C. difficile R20291, which is involved in bacterial autolysis. The gene 0971 deletion mutant (R20291Δ0971) generated with CRISPR-AsCpfI exhibited significantly delayed cell autolysis and increased cell viability compared to R20291, and the purified Cwl0971 exhibited hydrolase activity for Bacillus subtilis cell wall. Meanwhile, 0971 gene deletion impaired TcdA and TcdB release due to the decreased cell autolysis in the stationary/late phase of cell growth. Moreover, sporulation of the mutant strain decreased significantly compared to the wild type strain. In vivo, the defect of Cwl0971 decreased fitness over the parent strain in a mouse infection model. Collectively, Cwl0971 is involved in cell wall lysis and cell viability, which affects toxin release, sporulation, germination, and pathogenicity of R20291, indicating that Cwl0971 could be an attractive target for C. difficile infection therapeutics and prophylactics.
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Affiliation(s)
- Duolong Zhu
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | | | - Brooke Rene Tomlinson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida
| | - Shaohui Wang
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Syed Hussain
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Domenica Flores
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Yongqun He
- Department of Microbiology and Immunology, and Center for Computational Medicine and Bioinformatics, Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
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Exoproteomic analysis of two MLST clade 2 strains of Clostridioides difficile from Latin America reveal close similarities. Sci Rep 2021; 11:13273. [PMID: 34168208 PMCID: PMC8225638 DOI: 10.1038/s41598-021-92684-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 06/04/2021] [Indexed: 02/04/2023] Open
Abstract
Clostridioides difficile BI/NAP1/ribotype 027 is an epidemic hypervirulent strain found worldwide, including in Latin America. We examined the genomes and exoproteomes of two multilocus sequence type (MLST) clade 2 C. difficile strains considered hypervirulent: ICC-45 (ribotype SLO231/UK[CE]821), isolated in Brazil, and NAP1/027/ST01 (LIBA5756), isolated during a 2010 outbreak in Costa Rica. C. difficile isolates were cultured and extracellular proteins were analyzed using high-performance liquid chromatography-tandem mass spectrometry. Genomic analysis revealed that these isolates shared most of the gene composition. Only 83 and 290 NAP1/027 genes were considered singletons in ICC-45 and NAP1/027, respectively. Exoproteome analysis revealed 197 proteins, of which 192 were similar in both strains. Only five proteins were exclusive to the ICC-45 strain. These proteins were involved with catalytic and binding functions and indirectly interacted with proteins related to pathogenicity. Most proteins, including TcdA, TcdB, flagellin subunit, and cell surface protein, were overrepresented in the ICC-45 strain; 14 proteins, including mature S-layer protein, were present in higher proportions in LIBA5756. Data are available via ProteomeXchange with identifier PXD026218. These data show close similarity between the genome and proteins in the supernatant of two strains with hypervirulent features isolated in Latin America and underscore the importance of epidemiological surveillance of the transmission and emergence of new strains.
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Marcos P, Whyte P, Rogers T, McElroy M, Fanning S, Frias J, Bolton D. The prevalence of Clostridioides difficile on farms, in abattoirs and in retail foods in Ireland. Food Microbiol 2021; 98:103781. [PMID: 33875209 DOI: 10.1016/j.fm.2021.103781] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/22/2021] [Accepted: 02/24/2021] [Indexed: 11/29/2022]
Abstract
An increasing proportion of Clostridioides difficile infections (CDI) are community acquired. This study tested farm, abattoir and retail food samples for C. difficile, using peer reviewed culture and molecular methods. The contamination rate on beef, sheep and broiler farms ranged from 2/30 (7%) to 25/30 (83%) in faeces, soil and water samples, while concentrations ranged from 2.9 log10 cfu/ml to 8.4 log10 cfu/g. The prevalence and associated counts were much lower in abattoir samples. Although 26/60 were C. difficile positive by enrichment and PCR, only 6 samples yielded counts by direct plating (1.1 log10 cfu/cm2 to 5.1 log10 cfu/g). At retail, 9/240 samples were C. difficile positive, including corned beef (1), spinach leaves (2), iceberg lettuce, little gem lettuce, wild rocket, coleslaw, whole milk yogurt and cottage cheese (1 sample each), with counts of up to 6.8 log10 cfu/g. The tcdA, tcdB, cdtA, cdtB, tcdC and tcdR genes were detected in 41%, 99.2%, 33.6%, 32%, 46.7% and 31.1%, respectively, of the 122 C. difficile isolates obtained. It was concluded that although the prevalence of C. difficile decreased along the food chain, retail foods were still heavily contaminated. This pathogen may therefore be foodborne, perhaps necessitating dietary advice for potentially vulnerable patients.
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Affiliation(s)
- Pilar Marcos
- Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland; School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Paul Whyte
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Thomas Rogers
- Clinical Microbiology, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Máire McElroy
- Central Veterinary Research Laboratory, Department of Agriculture, Food and the Marine, Backweston, Celbridge, Kildare, Ireland
| | - Seamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin, D04 N2E5, Ireland
| | - Jesus Frias
- Environmental Sustainability and Health Institute, Technological University Dublin, Grangegorman, Dublin 7, Ireland
| | - Declan Bolton
- Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
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Vitucci JC, Pulse M, Tabor-Simecka L, Simecka J. Epidemic ribotypes of Clostridium (now Clostridioides) difficile are likely to be more virulent than non-epidemic ribotypes in animal models. BMC Microbiol 2020; 20:27. [PMID: 32024477 PMCID: PMC7003423 DOI: 10.1186/s12866-020-1710-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/21/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Clostridioides difficile infections have become more frequently diagnosed and associated with greater disease severity, which has resulted in an increase burden on the healthcare system. These increases are attributed to the increased prevalence of hypervirulent strains encompassing select ribotypes. These epidemic ribotypes were characterized as hypervirulent due to higher in vitro spore and toxin production, as well as increased incidence, severity and mortality within patients. However, it is unclear whether epidemic ribotypes are truly more virulent than non-epidemic ribotypes in vivo. Furthermore, there is conflicting evidence about the ability of a strain's in vitro phenotype to be predictive of their in vivo virulence. The goals of the current studies were to determine if epidemic ribotypes are more virulent than other ribotypes in animal models, and whether the in vitro virulence phenotype of an isolate or ribotype predict in vivo virulence. RESULTS To determine if epidemic strains were truly more virulent than other non-epidemic strains, the in vivo virulence of 13 C. difficile isolates (7 non-epidemic and 6 epidemic ribotype isolates) were determined in murine and hamster models of CDI. The isolates of epidemic ribotype of C. difficile were found to be more virulent in both the murine and hamster models than non-epidemic isolates. In particular, the group of epidemic ribotypes of C. difficile had lower LD50 values in hamsters. The increased severity of disease was associated with higher levels of Toxin A and Toxin B production found in fecal samples, but not numbers of organisms recovered. The isolates were further characterized for their in vitro virulence phenotypes, e.g. toxin production, growth rates, spore formation and adherence of spores to intestinal epithelial cell lines. Although there were higher levels of toxins produced and greater adherence for the group of epidemic ribotypes, the in vitro profiles of individual isolates were not always predictive of their in vivo virulence. CONCLUSIONS Overall, the group of epidemic ribotypes of C. difficile were more virulent in vivo despite individual isolates having similar phenotypes to the non-epidemic isolates in vitro.
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Affiliation(s)
- John C Vitucci
- Department of Pharmaceutical Sciences and UNTHSC Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Mark Pulse
- Department of Pharmaceutical Sciences and UNTHSC Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | | | - Jerry Simecka
- Department of Pharmaceutical Sciences and UNTHSC Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA.
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Zamani AH, Razmyar J, Berger FK, Kalidari GA, Jamshidi A. Isolation and toxin gene detection of Clostridium ( Clostridioides) difficile from traditional and commercial quail farms and packed quail meat for market supply - Short communication. Acta Vet Hung 2019; 67:499-504. [PMID: 31842596 DOI: 10.1556/004.2019.049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Clostridium (Clostridioides) difficile is a Gram-positive anaerobic rod-shaped bacterium and the main cause of nosocomial diarrhoea in humans. In recent years, the transmission of C. difficile from environmental reservoirs (e.g. food) to humans has become a major focus of research. The aim of this study was to investigate the prevalence and corresponding toxin genes of C. difficile in faecal samples and meat of quails. Thirty samples of packed quail meat in Mashhad, Iran and 500 faecal samples (pooled to n = 5) were collected on quail farms in the Northeastern Khorasan region for further investigation. Of 100 pooled quail faecal samples 10% showed cultural growth of C. difficile. In meat samples two out of 30 specimens (7%) showed cultural growth. In six of ten isolates from faecal samples toxin genes (tcdB and tcdA) were present, while four isolates harboured no toxin genes. However, in meat isolates no toxin genes were present. Mutations in the tcdC gene were not detected, indicating that 'hypervirulent' strains such as RT027 and RT078 were not present. The data suggest that quail and quail products might hold a potential for the spread of C. difficile.
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Affiliation(s)
| | - Jamshid Razmyar
- 2Department of Avian Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
- 3Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Fabian K. Berger
- 4National Reference Center for Clostridioides (Clostridium) difficile, Institute of Medical Microbiology and Hygiene, University of Saarland, Homburg/Saar, Germany
| | - Gholam Ali Kalidari
- 3Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Abdollah Jamshidi
- 5Department of Food Hygiene and Aquatics, School of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
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Saito R, Usui Y, Ayibieke A, Nakajima J, Prah I, Sonobe K, Aiso Y, Ito S, Itsui Y, Hadano Y, Nukui Y, Koike R, Tohda S. Hypervirulent clade 2, ribotype 019/sequence type 67 Clostridioides difficile strain from Japan. Gut Pathog 2019; 11:54. [PMID: 31700548 PMCID: PMC6827173 DOI: 10.1186/s13099-019-0336-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/25/2019] [Indexed: 12/12/2022] Open
Abstract
Background Clostridioides difficile ribotype (RT) 019/sequence type (ST) 67 strains belong to a hypervirulent lineage closely related to RT027/ST1; however, limited data are available for hypervirulent clade 2 lineages in Japan. Herein, we report the draft genome of a C. difficile strain B18-123 belonging to clade 2, RT019/ST67 for the first time in Japan. Results The pathogenicity locus carried by B18-123 (19.6 kb) showed higher homology (97.29% nucleotide identity) with strain R20291 (RT027/ST1) than the reference strain 630 (RT012/ST54), and B18-123 harbored 8-nucleotide substitutions in tcdC. However, it did not contain an 18-base pair (bp) deletion or a single-bp deletion at position 117 in tcdC, which was identified in the previous strain R20291. A cytotoxicity assay revealed similar cytotoxicity levels between strains B18-123 and ATCC BAA-1870 (RT027/ST1). The B18-123 strain was found to be susceptible to metronidazole and vancomycin. Conclusion Our findings contribute to the further understanding of the characteristics of hypervirulent clade 2 including RT019/ST67 lineages.
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Affiliation(s)
- Ryoichi Saito
- 1Department of Molecular Microbiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,2Department of Infection Control and Prevention, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Yukino Usui
- 1Department of Molecular Microbiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Alafate Ayibieke
- 1Department of Molecular Microbiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Jun Nakajima
- 2Department of Infection Control and Prevention, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan.,3Department of Clinical Laboratory, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Isaac Prah
- 1Department of Molecular Microbiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kazunari Sonobe
- 2Department of Infection Control and Prevention, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan.,3Department of Clinical Laboratory, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Yoshibumi Aiso
- 2Department of Infection Control and Prevention, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Shiori Ito
- 4Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Yasuhiro Itsui
- 4Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Yoshiro Hadano
- 2Department of Infection Control and Prevention, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Yoko Nukui
- 2Department of Infection Control and Prevention, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Ryuji Koike
- 2Department of Infection Control and Prevention, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
| | - Shuji Tohda
- 3Department of Clinical Laboratory, Tokyo Medical and Dental University Medical Hospital, Tokyo, Japan
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Zhu D, Bullock J, He Y, Sun X. Cwp22, a novel peptidoglycan cross-linking enzyme, plays pleiotropic roles in Clostridioides difficile. Environ Microbiol 2019; 21:3076-3090. [PMID: 31173438 DOI: 10.1111/1462-2920.14706] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 06/01/2019] [Accepted: 06/05/2019] [Indexed: 12/23/2022]
Abstract
Clostridioides difficile is a Gram-positive, spore-forming, toxin-producing anaerobe pathogen, and can induce nosocomial antibiotic-associated intestinal disease. While production of toxin A (TcdA) and toxin B (TcdB) contribute to the main pathogenesis of C. difficile, adhesion and colonization of C. difficile in the host gut are prerequisites for disease onset. Previous cell wall proteins (CWPs) were identified that were implicated in C. difficile adhesion and colonization. In this study, we predicted and characterized Cwp22 (CDR20291_2601) from C. difficile R20291 to be involved in bacterial adhesion based on the Vaxign reverse vaccinology tool. The ClosTron-generated cwp22 mutant showed decreased TcdA and TcdB production during early growth, and increased cell permeability and autolysis. Importantly, the cwp22 mutation impaired cellular adherence in vitro and decreased cytotoxicity and fitness over the parent strain in a mouse infection model. Furthermore, lactate dehydrogenase cytotoxicity assay, live-dead cell staining and transmission electron microscopy confirmed the decreased cell viability of the cwp22 mutant. Thus, Cwp22 is involved in cell wall integrity and cell viability, which could affect most phenotypes of R20291. Our data suggest that Cwp22 is an attractive target for C. difficile infection therapeutics and prophylactics.
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Affiliation(s)
- Duolong Zhu
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Jessica Bullock
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Yongqun He
- Department of Microbiology and Immunology, and Center for Computational Medicine and Bioinformatics, Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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14
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Evaluation of protective effect of Lactobacillus acidophilus La-5 on toxicity and colonization of Clostridium difficile in human epithelial cells in vitro. Anaerobe 2018; 55:142-151. [PMID: 30576791 DOI: 10.1016/j.anaerobe.2018.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 11/24/2018] [Accepted: 12/17/2018] [Indexed: 12/14/2022]
Abstract
Clostridium difficile infection is a range of toxin - mediated intestinal diseases that is often acquired in hospitals and small communities in developed countries. The main virulence factors of C. difficile are two exotoxins, toxin A and toxin B, which damage epithelial cells and manifest as colonic inflammation and mild to severe diarrhea. Inhibiting C. difficile adherence, colonization, and reducing its toxin production could substantially minimize its pathogenicity and lead to faster recovery from the disease. This study investigated the efficacy of probiotic secreted bioactive molecules from Lactobacillus acidophilus La-5, in decreasing C. difficile attachment and cytotoxicity in human epithelial cells in vitro. L. acidophilus La-5 cell-free supernatant (La-5 CFS) was used to treat the hypervirulent C. difficile ribotype 027 culture with subsequent monitoring of cytotoxicity and adhesion. In addition, the effect of pretreating cell lines with La-5 CFS in protecting cells from the cytotoxicity of C. difficile culture filtrate or bacterial cell attachment was examined. La-5 CFS substantially reduced the cytotoxicity and cytopathic effect of C. difficile culture filtrate on HT-29 and Caco-2 cells. Furthermore, La-5 CFS significantly reduced attachment of the C. difficile bacterial cells on both cell lines. It was also found that pretreatment of cell lines with La-5 CFS effectively protected cell lines from cytotoxicity and adherence of C. difficile. Our study suggests that La-5 CFS could potentially be used to prevent and cure C. difficile infection and relapses.
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15
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Ransom EM, Kaus GM, Tran PM, Ellermeier CD, Weiss DS. Multiple factors contribute to bimodal toxin gene expression in Clostridioides (Clostridium) difficile. Mol Microbiol 2018; 110:533-549. [PMID: 30125399 PMCID: PMC6446242 DOI: 10.1111/mmi.14107] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/10/2018] [Accepted: 08/11/2018] [Indexed: 12/14/2022]
Abstract
Clostridioides (formerly Clostridium) difficile produces two major toxins, TcdA and TcdB, upon entry into stationary phase. Transcription of tcdA and tcdB requires the specialized sigma factor, σTcdR , which also directs RNA Polymerase to transcribe tcdR itself. We fused a gene for a red fluorescent protein to the tcdA promoter to study toxin gene expression at the level of individual C. difficile cells. Surprisingly, only a subset of cells became red fluorescent upon entry into stationary phase. Breaking the positive feedback loop that controls σTcdR production by engineering cells to express tcdR from a tetracycline-inducible promoter resulted in uniform fluorescence across the population. Experiments with two regulators of tcdR expression, σD and CodY, revealed neither is required for bimodal toxin gene expression. However, σD biased cells toward the Toxin-ON state, while CodY biased cells toward the Toxin-OFF state. Finally, toxin gene expression was observed in sporulating cells. We conclude that (i) toxin production is regulated by a bistable switch governed by σTcdR , which only accumulates to high enough levels to trigger toxin gene expression in a subset of cells, and (ii) toxin production and sporulation are not mutually exclusive developmental programs.
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Affiliation(s)
- Eric M. Ransom
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
| | - Gabriela M. Kaus
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
| | - Phuong M. Tran
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
| | - Craig D. Ellermeier
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
- Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242
| | - David S. Weiss
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
- Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242
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16
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Schäffler H, Breitrück A. Clostridium difficile - From Colonization to Infection. Front Microbiol 2018; 9:646. [PMID: 29692762 PMCID: PMC5902504 DOI: 10.3389/fmicb.2018.00646] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/19/2018] [Indexed: 12/19/2022] Open
Abstract
Clostridium difficile is the most frequent cause of nosocomial antibiotic-associated diarrhea. The incidence of C. difficile infection (CDI) has been rising worldwide with subsequent increases in morbidity, mortality, and health care costs. Asymptomatic colonization with C. difficile is common and a high prevalence has been found in specific cohorts, e.g., hospitalized patients, adults in nursing homes and in infants. However, the risk of infection with C. difficile differs significantly between these cohorts. While CDI is a clear indication for therapy, colonization with C. difficile is not believed to be a direct precursor for CDI and therefore does not require treatment. Antibiotic therapy causes alterations of the intestinal microbial composition, enabling C. difficile colonization and consecutive toxin production leading to disruption of the colonic epithelial cells. Clinical symptoms of CDI range from mild diarrhea to potentially life-threatening conditions like pseudomembranous colitis or toxic megacolon. While antibiotics are still the treatment of choice for CDI, new therapies have emerged in recent years such as antibodies against C. difficile toxin B and fecal microbial transfer (FMT). This specific therapy for CDI underscores the role of the indigenous bacterial composition in the prevention of the disease in healthy individuals and its role in the pathogenesis after alteration by antibiotic treatment. In addition to the pathogenesis of CDI, this review focuses on the colonization of C. difficile in the human gut and factors promoting CDI.
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Affiliation(s)
- Holger Schäffler
- Division of Gastroenterology, Department of Medicine II, University of Rostock, Rostock, Germany
| | - Anne Breitrück
- Extracorporeal Immunomodulation Unit, Fraunhofer Institute for Cell Therapy and Immunology, Rostock, Germany.,Institute of Medical Microbiology, Virology and Hygiene, University of Rostock, Rostock, Germany
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17
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Present and past perspectives on Clostridium difficile infection. REVISTA DE GASTROENTEROLOGÍA DE MÉXICO 2018. [DOI: 10.1016/j.rgmxen.2017.07.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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18
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Abstract
Clostridium difficile is the most frequent cause of nosocomial antibiotic-associated diarrhea. The incidence of C. difficile infection (CDI) has been rising worldwide with subsequent increases in morbidity, mortality, and health care costs. Asymptomatic colonization with C. difficile is common and a high prevalence has been found in specific cohorts, e.g., hospitalized patients, adults in nursing homes and in infants. However, the risk of infection with C. difficile differs significantly between these cohorts. While CDI is a clear indication for therapy, colonization with C. difficile is not believed to be a direct precursor for CDI and therefore does not require treatment. Antibiotic therapy causes alterations of the intestinal microbial composition, enabling C. difficile colonization and consecutive toxin production leading to disruption of the colonic epithelial cells. Clinical symptoms of CDI range from mild diarrhea to potentially life-threatening conditions like pseudomembranous colitis or toxic megacolon. While antibiotics are still the treatment of choice for CDI, new therapies have emerged in recent years such as antibodies against C. difficile toxin B and fecal microbial transfer (FMT). This specific therapy for CDI underscores the role of the indigenous bacterial composition in the prevention of the disease in healthy individuals and its role in the pathogenesis after alteration by antibiotic treatment. In addition to the pathogenesis of CDI, this review focuses on the colonization of C. difficile in the human gut and factors promoting CDI.
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Affiliation(s)
- Holger Schäffler
- Division of Gastroenterology, Department of Medicine II, University of Rostock, Rostock, Germany
| | - Anne Breitrück
- Extracorporeal Immunomodulation Unit, Fraunhofer Institute for Cell Therapy and Immunology, Rostock, Germany
- Institute of Medical Microbiology, Virology and Hygiene, University of Rostock, Rostock, Germany
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19
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Peng Z, Liu S, Meng X, Liang W, Xu Z, Tang B, Wang Y, Duan J, Fu C, Wu B, Wu A, Li C. Genome characterization of a novel binary toxin-positive strain of Clostridium difficile and comparison with the epidemic 027 and 078 strains. Gut Pathog 2017; 9:42. [PMID: 28794800 PMCID: PMC5547579 DOI: 10.1186/s13099-017-0191-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 07/25/2017] [Indexed: 12/13/2022] Open
Abstract
Background Clostridium difficile is an anaerobic Gram-positive spore-forming gut pathogen that causes antibiotic-associated diarrhea worldwide. A small number of C. difficile strains express the binary toxin (CDT), which is generally found in C. difficile 027 (ST1) and/or 078 (ST11) in clinic. However, we isolated a binary toxin-positive non-027, non-078 C. difficile LC693 that is associated with severe diarrhea in China. The genotype of this strain was determined as ST201. To understand the pathogenesis-basis of C. difficile ST201, the strain LC693 was chosen for whole genome sequencing, and its genome sequence was analyzed together with the other two ST201 strains VL-0104 and VL-0391 and compared to the epidemic 027/ST1 and 078/ST11 strains. Results The project finally generated an estimated genome size of approximately 4.07 Mbp for strain LC693. Genome size of the three ST201 strains ranged from 4.07 to 4.16 Mb, with an average GC content between 28.5 and 28.9%. Phylogenetic analysis demonstrated that the ST201 strains belonged to clade 3. The ST201 genomes contained more than 40 antibiotic resistance genes and 15 of them were predicted to be associated with vancomycin-resistance. The ST201 strains contained a larger PaLoc with a Tn6218 element inserted than the 027/ST1 and 078/ST11 strains, and encoded a truncated TcdC. In addition, the ST201 strains contained intact binary toxin coding and regulation genes which are highly homologous to the 027/ST1 strain. Genome comparison of the ST201 strains with the epidemic 027 and 078 strain identified 641 genes specific for C. difficile ST201, and a number of them were predicted as fitness and virulence associated genes. The presence of those genes also contributes to the pathogenesis of the ST201 strains. Conclusions In this study, the genomic characterization of three binary toxin-positive C. difficile ST201 strains in clade 3 was discussed and compared to the genomes of the epidemic 027 and the 078 strains. Our analysis identified a number fitness and virulence associated genes/loci in the ST201 genomes that contribute to the pathogenesis of C. difficile ST201. Electronic supplementary material The online version of this article (doi:10.1186/s13099-017-0191-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhong Peng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Sidi Liu
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Xiujuan Meng
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Wan Liang
- MOE Key Laboratory of Animal Genetics, Breeding, and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Zhuofei Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Biao Tang
- Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang China
| | - Yuanguo Wang
- The Hormel Institute, University of Minnesota, Austin, MN 55912 USA
| | - Juping Duan
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China.,Department of Pharmacy, Changsha Hospital of Traditional Chinese Medicine, Changsha, 410000 Hunan China
| | - Chenchao Fu
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Bin Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Anhua Wu
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
| | - Chunhui Li
- Infection Control Center, Xiangya Hospital of Central South University, Changsha, 410008 Hunan China
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20
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Álvarez-Hernández DA, González-Chávez AM, González-Hermosillo-Cornejo D, Franyuti-Kelly GA, Díaz-Girón-Gidi A, Vázquez-López R. Present and past perspectives on Clostridium difficile infection. REVISTA DE GASTROENTEROLOGÍA DE MÉXICO 2017; 83:41-50. [PMID: 28684034 DOI: 10.1016/j.rgmx.2017.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 03/14/2017] [Accepted: 03/29/2017] [Indexed: 01/05/2023]
Abstract
Clostridium difficile is a Gram-positive bacillus that has become one of the main hospital-acquired human gastrointestinal infections in recent years. Its incidence is on the rise, involving more virulent strains, affecting new and previously uncontemplated groups of patients, and producing changes in clinical presentation and treatment response that influence disease outcome. Early diagnosis and disease stratification based on the severity of C.difficile infection are essential for therapeutic management and the implementation of containment measures. However, the speed at which new strains with greater pathogenicity are developing is surpassing that of the development of new drugs, making it necessary to validate other therapeutic options. The present article is a review of the epidemiologic, pathophysiologic, diagnostic, and therapeutic aspects of C.difficile infection, from its first isolation to the present date, that aims to contribute to the preparation of general physicians and specialists, so that patients with this infection receive opportune and quality medical attention.
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Affiliation(s)
- D A Álvarez-Hernández
- Coordinación de Servicios Médicos, Cruz Roja Mexicana I.A.P., Delegación Huixquilucan, Huixquilucan, Estado de México, México.
| | - A M González-Chávez
- Departamento de Cirugía General, Hospital Español de México, Ciudad de México, México
| | | | - G A Franyuti-Kelly
- Facultad de Ciencias de la Salud, Universidad Anáhuac México Norte, Naucalpan de Juárez, Estado de México, México
| | - A Díaz-Girón-Gidi
- Departamento de Cirugía General, Fundación Clínica Médica Sur, Ciudad de México, México
| | - R Vázquez-López
- Departamento de Microbiología y Parasitología, Facultad de Ciencias de la Salud, Universidad Anáhuac México Norte, Naucalpan de Juárez, Estado de México, México
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21
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The Contribution of Bacteriophages to the Biology and Virulence of Pathogenic Clostridia. ADVANCES IN APPLIED MICROBIOLOGY 2017; 101:169-200. [PMID: 29050666 DOI: 10.1016/bs.aambs.2017.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bacteriophages are key players in the evolution of most bacteria. Temperate phages have been associated with virulence of some of the deadliest pathogenic bacteria. Among the most notorious cases, the genes encoding the botulinum neurotoxin produced by Clostridium botulinum types C and D and the α-toxin (TcnA) produced by Clostridium novyi are both encoded within prophage genomes. Clostridium difficile is another important human pathogen and the recent identification of a complete binary toxin locus (CdtLoc) carried on a C. difficile prophage raises the potential for horizontal transfer of toxin genes by mobile genetic elements. Although the TcdA and TcdB toxins produced by C. difficile have never been found outside the pathogenicity locus (PaLoc), some prophages can still influence their production. Prophages can alter the expression of several metabolic and regulatory genes in C. difficile, as well as cell surface proteins such as CwpV, which confers phage resistance. Homologs of an Agr-like quorum sensing system have been identified in a C. difficile prophage, suggesting that it could possibly participate in cell-cell communication. Yet, other C. difficile prophages contain riboswitches predicted to recognize the secondary messenger molecule c-di-GMP involved in bacterial multicellular behaviors. Altogether, recent findings on clostridial phages underline the diversity of mechanisms and intricate relationship linking phages with their host. Here, milestone discoveries linking phages and virulence of some of the most pathogenic clostridial species will be retraced, with a focus on C. botulinum, C. novyi, C. difficile, and Clostridium perfringens phages, for which evidences are mostly available.
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Abstract
Clostridium difficile infections (CDIs) have emerged as one of the principal threats to the health of hospitalized and immunocompromised patients. The importance of C difficile colonization is increasingly recognized not only as a source for false-positive clinical testing but also as a source of new infections within hospitals and other health care environments. In the last five years, several new treatment strategies that capitalize on the increasing understanding of the altered microbiome and host defenses in patients with CDI have completed clinical trials, including fecal microbiota transplantation. This article highlights the changing epidemiology, laboratory diagnostics, pathogenesis, and treatment of CDI.
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23
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Comparative Genome Analysis and Global Phylogeny of the Toxin Variant Clostridium difficile PCR Ribotype 017 Reveals the Evolution of Two Independent Sublineages. J Clin Microbiol 2016; 55:865-876. [PMID: 28031436 PMCID: PMC5328454 DOI: 10.1128/jcm.01296-16] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 11/09/2016] [Indexed: 12/21/2022] Open
Abstract
The diarrheal pathogen Clostridium difficile consists of at least six distinct evolutionary lineages. The RT017 lineage is anomalous, as strains only express toxin B, compared to strains from other lineages that produce toxins A and B and, occasionally, binary toxin. Historically, RT017 initially was reported in Asia but now has been reported worldwide. We used whole-genome sequencing and phylogenetic analysis to investigate the patterns of global spread and population structure of 277 RT017 isolates from animal and human origins from six continents, isolated between 1990 and 2013. We reveal two distinct evenly split sublineages (SL1 and SL2) of C. difficile RT017 that contain multiple independent clonal expansions. All 24 animal isolates were contained within SL1 along with human isolates, suggesting potential transmission between animals and humans. Genetic analyses revealed an overrepresentation of antibiotic resistance genes. Phylogeographic analyses show a North American origin for RT017, as has been found for the recently emerged epidemic RT027 lineage. Despite having only one toxin, RT017 strains have evolved in parallel from at least two independent sources and can readily transmit between continents.
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24
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Zhang BZ, Cai J, Yu B, Hua Y, Lau CC, Kao RYTT, Sze KH, Yuen KY, Huang JD. A DNA vaccine targeting TcdA and TcdB induces protective immunity against Clostridium difficile. BMC Infect Dis 2016; 16:596. [PMID: 27770789 PMCID: PMC5075199 DOI: 10.1186/s12879-016-1924-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/12/2016] [Indexed: 01/04/2023] Open
Abstract
Background Clostridium difficile-associated disease (CDAD) constitutes a great majority of hospital diarrhea cases in industrialized countries and is induced by two types of large toxin molecules: toxin A (TcdA) and toxin B (TcdB). Development of immunotherapeutic approaches, either active or passive, has seen a resurgence in recent years. Studies have described vaccine plasmids that express either TcdA and/or TcdB receptor binding domain (RBD). However, the effectiveness of one vector encoding both toxin RBDs against CDAD has not been evaluated. Methods In the study, we constructed highly optimized plasmids to express the receptor binding domains of both TcdA and TcdB from a single vector. The DNA vaccine was evaluated in two animal models for its immunogenicity and protective effects. Results The DNA vaccine induced high levels of serum antibodies to toxin A and/or B and demonstrated neutralizing activity in both in vitro and in vivo systems. In a C. difficile hamster infection model, immunization with the DNA vaccine reduced infection severity and conferred significant protection against a lethal C. difficile strain. Conclusions This study has demonstrated a single plasmid encoding the RBD domains of C. difficile TcdA and TcdB as a DNA vaccine that could provide protection from C. difficile disease.
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Affiliation(s)
- Bao-Zhong Zhang
- School of Biomedical Sciences, The University of Hong Kong, Li Ka Shing Faculty of Medicine, 3/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong, China.,Department of Microbiology, The University of Hong Kong, University Pathology Building, Pokfulam, Hong Kong, China.,HKU-Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China
| | - Jianpiao Cai
- Department of Microbiology, The University of Hong Kong, University Pathology Building, Pokfulam, Hong Kong, China
| | - Bin Yu
- School of Biomedical Sciences, The University of Hong Kong, Li Ka Shing Faculty of Medicine, 3/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - Yanhong Hua
- School of Biomedical Sciences, The University of Hong Kong, Li Ka Shing Faculty of Medicine, 3/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - Candy Choiyi Lau
- Department of Microbiology, The University of Hong Kong, University Pathology Building, Pokfulam, Hong Kong, China
| | - Richard Yi-Tsun Tsun Kao
- Department of Microbiology, The University of Hong Kong, University Pathology Building, Pokfulam, Hong Kong, China
| | - Kong-Hung Sze
- Department of Microbiology, The University of Hong Kong, University Pathology Building, Pokfulam, Hong Kong, China
| | - Kwok-Yung Yuen
- Department of Microbiology, The University of Hong Kong, University Pathology Building, Pokfulam, Hong Kong, China.
| | - Jian-Dong Huang
- School of Biomedical Sciences, The University of Hong Kong, Li Ka Shing Faculty of Medicine, 3/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong, China. .,HKU-Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China. .,The Centre for Synthetic Biology Engineering Research, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen, China.
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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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Predominance and high antibiotic resistance of the emerging Clostridium difficile genotypes NAPCR1 and NAP9 in a Costa Rican hospital over a 2-year period without outbreaks. Emerg Microbes Infect 2016; 5:e42. [PMID: 27165560 PMCID: PMC4893543 DOI: 10.1038/emi.2016.38] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/18/2015] [Accepted: 01/07/2016] [Indexed: 12/19/2022]
Abstract
Clostridium difficile is the major causative agent of nosocomial antibiotic-associated diarrhea. In a 2009 outbreak of C. difficile-associated diarrhea that was recorded in a major Costa Rican hospital, the hypervirulent NAP1 strain (45%) predominated together with a local genotype variant (NAPCR1, 31%). Both strains were fluoroquinolone-resistant and the NAPCR1 genotype, in addition, was resistant to clindamycin and rifampicin. We now report on the genotypes and antibiotic susceptibilities of 68 C. difficile isolates from a major Costa Rican hospital over a 2-year period without outbreaks. In contrast to our previous findings, no NAP1 strains were detected, and for the first time in a Costa Rican hospital, a significant fraction of the isolates were NAP9 strains (n=14, 21%). The local NAPCR1 genotype remained prevalent (n=18, 26%) and coexisted with 14 strains (21%) of classic hospital NAP types (NAP2, NAP4, and NAP6), eight new genotypes (12%), four environmental strains classified as NAP10 or NAP11 (6%), three strains without NAP designation (4%) and seven non-toxigenic strains (10%). All 68 strains were resistant to ciprofloxacin, 88% were resistant to clindamycin and 50% were resistant to moxifloxacin and rifampicin. Metronidazole and vancomycin susceptibilities were universal. The NAPCR1 and NAP9 strains, which have been associated with more severe clinical infections, were more resistant to antibiotics than the other strains. Altogether, our results confirm that the epidemiology of C. difficile infection is dynamic and that A−B+ strains from the NAP9 type are on the rise not only in the developed world. Moreover, our results reveal that the local NAPCR1 strains still circulate in the country without causing outbreaks but with equally high antibiotic-resistance rates and levels.
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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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Characterization of Clostridium difficile Strains in British Columbia, Canada: A Shift from NAP1 Majority (2008) to Novel Strain Types (2013) in One Region. CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2016; 2016:8207418. [PMID: 27366181 PMCID: PMC4904575 DOI: 10.1155/2016/8207418] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/24/2015] [Indexed: 12/18/2022]
Abstract
Background. Clostridium difficile is a major cause of gastrointestinal illness. Epidemic NAP1 strains contain toxins A and B, a deletion in repressor tcdC, and a binary toxin. Objectives. To determine the molecular epidemiology of C. difficile in British Columbia and compare between two time points in one region. Methods. C. difficile isolates from hospital and community laboratories (2008) and one Island Health hospital laboratory (2013) were characterized by pulsed-field gel electrophoresis, PCR-ribotyping, toxin possession, tcdC genotype, and antimicrobial susceptibility. Results. In 2008, 42.7% of isolates had NAP1 designation. Hospital-collected isolates were associated with older patients and more NAP1 types. Unlike other isolates, most NAP1 isolates possessed binary toxin and a 19 bp loss in tcdC. All isolates were susceptible to metronidazole and vancomycin. A 2013 follow-up revealed a 28.9% decrease in NAP1 isolates and 20.0% increase in isolates without NAP designation in one region. Then, community-associated cases were seen in younger patients, while NAP types were evenly distributed. Isolates without NAP designation did not cluster with a PFGE pattern or ribotype. Conclusions. Evaluation of C. difficile infections within British Columbia revealed demographic associations, epidemiological shifts, and characteristics of strain types. Continuous surveillance of C. difficile will enable detection of emerging strains.
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Angione SL, Croote D, Leung JW, Mermel LA, Tripathi A. Single fluorophore melting curve analysis for detection of hypervirulent Clostridium difficile. J Med Microbiol 2015; 65:62-70. [PMID: 26516039 DOI: 10.1099/jmm.0.000199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This study demonstrates a novel detection assay able to identify and subtype strains of Clostridium difficile. Primers carefully designed for melting curve analysis amplify DNA from three C. difficile genes, tcdB, tcdC and cdtB, during quantitative (q)PCR. The tcdB gene allows for confirmation of organism presence, whilst the tcdC and cdtB genes allow for differentiation of virulence status, as deletions in the tcdC gene and the concurrent presence of the cdtB gene, which produces binary toxin, are associated with hypervirulence. Following qPCR, subtyping is then achieved by automated, inline melting curve analysis using only a single intercalating dye and verified by microchip electrophoresis. This assay represents a novel means of distinguishing between toxigenic and hypervirulent C. difficile strains NAP1/027/BI and 078 ribotype, which are highly prevalent hypervirulent strains in humans. This methodology can help rapidly detect and identify C. difficile strains that impose a significant health and economic burden in hospitals and other healthcare settings.
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Affiliation(s)
- Stephanie L Angione
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA
| | - Derek Croote
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA
| | - Joshua W Leung
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA
| | - Leonard A Mermel
- Division of Infectious Diseases, Department of Medicine, Rhode Island Hospital, , Providence, RI, USA.,Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Anubhav Tripathi
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA
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Abstract
Clostridium difficile is the cause of most frequently occurring nosocomial diarrhea worldwide. As an enteropathogen, C. difficile must be exposed to multiple exogenous genetic elements in bacteriophage-rich gut communities. CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems allow bacteria to adapt to foreign genetic invaders. Our recent data revealed active expression and processing of CRISPR RNAs from multiple type I-B CRISPR arrays in C. difficile reference strain 630. Here, we demonstrate active expression of CRISPR arrays in strain R20291, an epidemic C. difficile strain. Through genome sequencing and host range analysis of several new C. difficile phages and plasmid conjugation experiments, we provide evidence of defensive function of the CRISPR-Cas system in both C. difficile strains. We further demonstrate that C. difficile Cas proteins are capable of interference in a heterologous host, Escherichia coli. These data set the stage for mechanistic and physiological analyses of CRISPR-Cas-mediated interactions of important global human pathogen with its genetic parasites. Clostridium difficile is the major cause of nosocomial infections associated with antibiotic therapy worldwide. To survive in bacteriophage-rich gut communities, enteropathogens must develop efficient systems for defense against foreign DNA elements. CRISPR-Cas systems have recently taken center stage among various anti-invader bacterial defense systems. We provide experimental evidence for the function of the C. difficile CRISPR system against plasmid DNA and bacteriophages. These data demonstrate the original features of active C. difficile CRISPR system and bring important insights into the interactions of this major enteropathogen with foreign DNA invaders during its infection cycle.
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Pérez-Cobas AE, Moya A, Gosalbes MJ, Latorre A. Colonization Resistance of the Gut Microbiota against Clostridium difficile. Antibiotics (Basel) 2015; 4:337-57. [PMID: 27025628 PMCID: PMC4790290 DOI: 10.3390/antibiotics4030337] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/03/2015] [Indexed: 02/06/2023] Open
Abstract
Antibiotics strongly disrupt the human gut microbiota, which in consequence loses its colonization resistance capacity, allowing infection by opportunistic pathogens such as Clostridium difficile. This bacterium is the main cause of antibiotic-associated diarrhea and a current problem in developed countries, since its incidence and severity have increased during the last years. Furthermore, the emergence of antibiotic resistance strains has reduced the efficiency of the standard treatment with antibiotics, leading to a higher rate of relapses. Here, we review recent efforts focused on the impact of antibiotics in the gut microbiome and their relationship with C. difficile colonization, as well as, in the identification of bacteria and mechanisms involved in the protection against C. difficile infection. Since a healthy gut microbiota is able to avoid pathogen colonization, restoration of the gut microbiota seems to be the most promising approach to face C. difficile infection, especially for recurrent cases. Therefore, it would be possible to design probiotics for patients undergoing antimicrobial therapies in order to prevent or fight the expansion of the pathogen in the gut ecosystem.
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Affiliation(s)
- Ana Elena Pérez-Cobas
- Joint Research Unit of Foundation for the Promotion of Health and Biomedical Research of Valencian Region (FISABIO) and the Cavanilles Institute of Biodiversity and Evolutionary Biology (ICBiBE) of the University of Valencia, Valencia 46020, Spain.
- CIBER in Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
| | - Andrés Moya
- Joint Research Unit of Foundation for the Promotion of Health and Biomedical Research of Valencian Region (FISABIO) and the Cavanilles Institute of Biodiversity and Evolutionary Biology (ICBiBE) of the University of Valencia, Valencia 46020, Spain.
- CIBER in Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
| | - María José Gosalbes
- Joint Research Unit of Foundation for the Promotion of Health and Biomedical Research of Valencian Region (FISABIO) and the Cavanilles Institute of Biodiversity and Evolutionary Biology (ICBiBE) of the University of Valencia, Valencia 46020, Spain.
- CIBER in Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
| | - Amparo Latorre
- Joint Research Unit of Foundation for the Promotion of Health and Biomedical Research of Valencian Region (FISABIO) and the Cavanilles Institute of Biodiversity and Evolutionary Biology (ICBiBE) of the University of Valencia, Valencia 46020, Spain.
- CIBER in Epidemiology and Public Health (CIBERESP), Madrid 28029, Spain.
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Couchman EC, Browne HP, Dunn M, Lawley TD, Songer JG, Hall V, Petrovska L, Vidor C, Awad M, Lyras D, Fairweather NF. Clostridium sordellii genome analysis reveals plasmid localized toxin genes encoded within pathogenicity loci. BMC Genomics 2015; 16:392. [PMID: 25981746 PMCID: PMC4434542 DOI: 10.1186/s12864-015-1613-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 05/05/2015] [Indexed: 11/17/2022] Open
Abstract
Background Clostridium sordellii can cause severe infections in animals and humans, the latter associated with trauma, toxic shock and often-fatal gynaecological infections. Strains can produce two large clostridial cytotoxins (LCCs), TcsL and TcsH, related to those produced by Clostridium difficile, Clostridium novyi and Clostridium perfringens, but the genetic basis of toxin production remains uncharacterised. Results Phylogenetic analysis of the genome sequences of 44 strains isolated from human and animal infections in the UK, US and Australia placed the species into four clades. Although all strains originated from animal or clinical disease, only 5 strains contained LCC genes: 4 strains contain tcsL alone and one strain contains tcsL and tcsH. Four toxin-positive strains were found within one clade. Where present, tcsL and tcsH were localised in a pathogenicity locus, similar to but distinct from that present in C. difficile. In contrast to C. difficile, where the LCCs are chromosomally localised, the C. sordellii tcsL and tcsH genes are localised on plasmids. Our data suggest gain and loss of entire toxigenic plasmids in addition to horizontal transfer of the pathogenicity locus. A high quality, annotated sequence of ATCC9714 reveals many putative virulence factors including neuraminidase, phospholipase C and the cholesterol-dependent cytolysin sordellilysin that are highly conserved between all strains studied. Conclusions Genome analysis of C. sordellii reveals that the LCCs, the major virulence factors, are localised on plasmids. Many strains do not contain the LCC genes; it is probable that in several of these cases the plasmid has been lost upon laboratory subculture. Our data are consistent with LCCs being the primary virulence factors in the majority of infections, but LCC-negative strains may precipitate certain categories of infection. A high quality genome sequence reveals putative virulence factors whose role in virulence can be investigated. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1613-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Edward C Couchman
- Department of Life Sciences, Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK.
| | | | - Matt Dunn
- Wellcome Trust Sanger Institute, Hinxton, UK.
| | | | - J Glenn Songer
- Department of Veterinary Science and Microbiology, University of Arizona, Tucson, USA.
| | - Val Hall
- Anaerobe Reference Laboratory, University Hospital of Wales, Cardiff, UK.
| | | | - Callum Vidor
- Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Milena Awad
- Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Dena Lyras
- Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia.
| | - Neil F Fairweather
- Department of Life Sciences, Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK.
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Targeting surface-layer proteins with single-domain antibodies: a potential therapeutic approach against Clostridium difficile-associated disease. Appl Microbiol Biotechnol 2015; 99:8549-62. [PMID: 25936376 PMCID: PMC4768215 DOI: 10.1007/s00253-015-6594-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/01/2015] [Accepted: 04/05/2015] [Indexed: 02/07/2023]
Abstract
Clostridium difficile is a leading cause of death from gastrointestinal infections in North America. Antibiotic therapy is effective, but the high incidence of relapse and the rise in hypervirulent strains warrant the search for novel treatments. Surface layer proteins (SLPs) cover the entire C. difficile bacterial surface, are composed of high-molecular-weight (HMW) and low-molecular-weight (LMW) subunits, and mediate adherence to host cells. Passive and active immunization against SLPs has enhanced hamster survival, suggesting that antibody-mediated neutralization may be an effective therapeutic strategy. Here, we isolated a panel of SLP-specific single-domain antibodies (VHHs) using an immune llama phage display library and SLPs isolated from C. difficile hypervirulent strain QCD-32g58 (027 ribotype) as a target antigen. Binding studies revealed a number of VHHs that bound QCD-32g58 SLPs with high affinity (KD = 3–6 nM) and targeted epitopes located on the LMW subunit of the SLP. The VHHs demonstrated melting temperatures as high as 75 °C, and a few were resistant to the gastrointestinal protease pepsin at physiologically relevant concentrations. In addition, we demonstrated the binding specificity of the VHHs to the major C. difficile ribotypes by whole cell ELISA, where all VHHs were found to bind 001 and 027 ribotypes, and a subset of antibodies were found to be broadly cross-reactive in binding cells representative of 012, 017, 023, and 078 ribotypes. Finally, we showed that several of the VHHs inhibited C. difficile QCD-32g58 motility in vitro. Targeting SLPs with VHHs may be a viable therapeutic approach against C. difficile-associated disease.
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Amy J, Johanesen P, Lyras D. Extrachromosomal and integrated genetic elements in Clostridium difficile. Plasmid 2015; 80:97-110. [PMID: 25929174 DOI: 10.1016/j.plasmid.2015.04.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/21/2022]
Abstract
Clostridium difficile is a major nosocomial pathogen, causing gastrointestinal disease in patients undergoing antibiotic therapy. This bacterium contains many extrachromosomal and integrated genetic elements, with recent genomic work giving new insights into their variability and distribution. This review summarises research conducted in this area over the last 30 years and includes a discussion on the functional contributions of these elements to host cell phenotypes, as well as encompassing recent genome sequencing studies that have contributed to our understanding of their evolution and dissemination. Importantly, we also include a review of antibiotic resistance determinants associated with mobile genetic elements since antibiotic use and the spread of antibiotic resistance are currently of significant global clinical importance.
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Affiliation(s)
- Jacob Amy
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Priscilla Johanesen
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Dena Lyras
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia.
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Abstract
Clostridium difficile is a spore-forming anaerobic gram-positive organism that is the leading cause of antibiotic-associated nosocomial infectious diarrhea in the Western world. This article describes the evolving epidemiology of C difficile infection (CDI) in the twenty-first century, evaluates the importance of vaccines against the disease, and defines the roles of both innate and adaptive host immune responses in CDI. The effects of passive immunotherapy and active vaccination against CDI in both humans and animals are also discussed.
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Affiliation(s)
- Chandrabali Ghose
- Aaron Diamond AIDS Research Center, 455 First Avenue, 7th Floor, New York, NY 10016, USA.
| | - Ciarán P Kelly
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
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Single nucleotide polymorphisms of the tcdC gene and presence of the binary toxin gene predict recurrent episodes of Clostridium difficile infection. Ann Surg 2015; 260:299-304. [PMID: 24374512 DOI: 10.1097/sla.0000000000000469] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To identify Clostridium difficile genotypes, which are associated with recurrent C difficile infection (RCDI). BACKGROUND Reliable bacterial genetic factors predicting RCDI are currently lacking. METHODS Inpatients and outpatients 18 years or older treated at our institution for C difficile infection (CDI) of any severity were consecutively enrolled. CDI was defined as symptoms of colitis with a positive PCR stool test. Each bacterial isolate was studied for virulence factors: tcdC mutations, including single nucleotide polymorphisms (SNPs) via PCR, the presence of genes for toxins A, B and binary toxin using restriction fragment length polymorphism, and identification of ribotype by PCR. χ tests, t tests, and logistic and linear regression were used to determine which virulence factors predicted RCDI and the need for hospital admission, with corrections made for multiple statistical comparisons. RESULTS Seventy-three patients (male: 52%; mean age: 66 ± 15 years) were studied. Binary toxin gene (P = 0.03) was associated with at least 1 episode of RCDI, as was the presence of SNPs C184T (P = 0.006) and A117T (P = 0.003). The presence of the binary toxin gene with either of these tcdC SNPs increased RCDI by 80% (P = 0.0002) but did not predict the need for hospital admission. None of the other virulence factors, including ribotype 027, were predictive of RCDI. CONCLUSIONS The presence of the binary toxin gene and tcdC SNPs C184T and A117T strongly predict RCDI. The presence of both tcdC SNPs and the binary toxin gene significantly increased the risk of RCDI, which might warrant longer antibiotic courses to eradicate the infection.
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The role of flagella in Clostridium difficile pathogenicity. Trends Microbiol 2015; 23:275-82. [PMID: 25659185 DOI: 10.1016/j.tim.2015.01.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/02/2014] [Accepted: 01/12/2015] [Indexed: 01/05/2023]
Abstract
Clostridium difficile is widely publicised as a problem in the health-care system. Disruption of the normal gut microbiota by antibiotic therapy allows C. difficile to colonise the colon. On colonisation, C. difficile produces two toxins that lead to disease, with symptoms ranging from mild-to-severe diarrhoea, to fulminant and often fatal pseudomembranous colitis (PMC). How C. difficile establishes initial colonisation of the host is an area of active investigation. Recently there has been increased research into the role of C. difficile flagella in colonisation and adherence. Novel research has also elucidated a more complex role of flagella in C. difficile virulence pertaining to the regulation of toxin gene expression. This review focuses on new insights into the specific role of C. difficile flagella in colonisation and toxin gene expression.
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Antimicrobial susceptibility patterns of Clostridium difficile strains belonging to different polymerase chain reaction ribotypes isolated in Poland in 2012. Anaerobe 2015; 31:37-41. [DOI: 10.1016/j.anaerobe.2014.09.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/26/2014] [Accepted: 09/04/2014] [Indexed: 12/16/2022]
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Mathur H, Rea MC, Cotter PD, Ross RP, Hill C. The potential for emerging therapeutic options for Clostridium difficile infection. Gut Microbes 2015; 5:696-710. [PMID: 25564777 PMCID: PMC4615897 DOI: 10.4161/19490976.2014.983768] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Clostridium difficile is mainly a nosocomial pathogen and is a significant cause of antibiotic-associated diarrhea. It is also implicated in the majority of cases of pseudomembranous colitis. Recently, advancements in next generation sequencing technology (NGS) have highlighted the extent of damage to the gut microbiota caused by broad-spectrum antibiotics, often resulting in C. difficile infection (CDI). Currently the treatment of choice for CDI involves the use of metronidazole and vancomycin. However, recurrence and relapse of CDI, even after rounds of metronidazole/vancomycin administration is a problem that must be addressed. The efficacy of alternative antibiotics such as fidaxomicin, rifaximin, nitazoxanide, ramoplanin and tigecycline, as well as faecal microbiota transplantation has been assessed and some have yielded positive outcomes against C. difficile. Some bacteriocins have also shown promising effects against C. difficile in recent years. In light of this, the potential for emerging treatment options and efficacy of anti-C. difficile vaccines are discussed in this review.
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Key Words
- ATCC, American Type Culture Collection
- CDI, Clostridium difficile infection
- CdtLoc, binary toxin locus
- Clostridium difficile
- DNA, deoxyribonucleic acid
- DPC, Dairy Products Collection
- ESCMID, European Society of Clinical Microbiology and Infectious Diseases
- ETEC, enterotoxigenic E. coli
- FDA, Food and Drug Administration
- FMT, faecal microbiota transplantation
- GIT, gastrointestinal tract
- HIV, human immunodeficiency virus
- IDSA, Infectious Diseases Society of America
- IgG, immunoglobulin G
- LTA, lipoteichoic acid
- M21V, methionine to valine substitution at residue 21
- MIC, minimum inhibitory concentration
- NGS, next generation sequencing
- NVB, Novacta Biosystems Ltd
- PMC, pseudomembranous colitis
- PaLoc, pathogenicity locus
- R027, ribotype 027
- RBD
- RBS, ribosome binding site
- RNA, ribonucleic acid
- SHEA, Society for Healthcare Epidemiology of America
- V15F, valine to phenylalanine substitution at residue 15
- antibiotics
- faecal microbiota transplantation
- receptor binding domain
- toxins
- vaccines
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Affiliation(s)
- Harsh Mathur
- School of Microbiology; University College Cork; Cork, Ireland,Teagasc Food Research Center; Moorepark; Fermoy, Ireland
| | - Mary C Rea
- Teagasc Food Research Center; Moorepark; Fermoy, Ireland,Alimentary Pharmabiotic Center; University College Cork; Cork, Ireland
| | - Paul D Cotter
- Teagasc Food Research Center; Moorepark; Fermoy, Ireland,Alimentary Pharmabiotic Center; University College Cork; Cork, Ireland,Correspondence to: Colin Hill; ; Paul D Cotter;
| | - R Paul Ross
- Alimentary Pharmabiotic Center; University College Cork; Cork, Ireland,College of Science; Engineering and Food Science; University College Cork; Cork, Ireland
| | - Colin Hill
- School of Microbiology; University College Cork; Cork, Ireland,Alimentary Pharmabiotic Center; University College Cork; Cork, Ireland,Correspondence to: Colin Hill; ; Paul D Cotter;
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Carter GP, Larcombe S, Li L, Jayawardena D, Awad MM, Songer JG, Lyras D. Expression of the large clostridial toxins is controlled by conserved regulatory mechanisms. Int J Med Microbiol 2014; 304:1147-59. [DOI: 10.1016/j.ijmm.2014.08.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 08/08/2014] [Accepted: 08/10/2014] [Indexed: 02/04/2023] Open
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Mooyottu S, Flock G, Kollanoor-Johny A, Upadhyaya I, Jayarao B, Venkitanarayanan K. Characterization of a multidrug resistant C. difficile meat isolate. Int J Food Microbiol 2014; 192:111-6. [PMID: 25440554 DOI: 10.1016/j.ijfoodmicro.2014.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 07/02/2014] [Accepted: 10/01/2014] [Indexed: 01/03/2023]
Abstract
Clostridium difficile is a pathogen of significant public health concern causing a life-threatening, toxin-mediated enteric disease in humans. The incidence and severity of the disease associated with C. difficile have increased in the US with the emergence of hypervirulent strains and community associated outbreaks. The detection of genotypically similar and identical C. difficile strains implicated from human infections in foods and food animals indicates the potential role of food as a source of community associated C. difficile disease. One hundred samples each of ground beef, pork and chicken obtained from geographically distant grocery stores in Connecticut were tested for C. difficile. Positive isolates were characterized by ribotyping, antibiotic susceptibility, toxin production and whole genome sequencing. Of the 300 meat samples, only two pork samples tested positive for C. difficile indicating a very low prevalence of C. difficile in meat. The isolates were non toxigenic; however, genome characterization revealed the presence of several antibiotic resistance genes and mobile elements that can potentially contribute to generation of multidrug resistant toxigenic C. difficile by horizontal gene transfer. Further studies are warranted to investigate potential food-borne transmission of the meat isolates and development of multi-drug resistance in these strains.
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Affiliation(s)
- Shankumar Mooyottu
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA
| | - Genevieve Flock
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA
| | - Anup Kollanoor-Johny
- Department of Animal Science, University of Minnesota, Saint Paul, MN 55108, USA
| | - Indu Upadhyaya
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA
| | - Bhushan Jayarao
- Department of Veterinary and Biomedical Sciences, Penn State Animal Diagnostic Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
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Phenotypic and genotypic analysis of Clostridium difficile isolates: a single-center study. J Clin Microbiol 2014; 52:4260-6. [PMID: 25275005 DOI: 10.1128/jcm.02115-14] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridium difficile infections (CDI) are a growing concern in North America, because of their increasing incidence and severity. Using integrated approaches, we correlated pathogen genotypes and host clinical characteristics for 46 C. difficile infections in a tertiary care medical center during a 6-month interval from January to June 2010. Multilocus sequence typing (MLST) demonstrated 21 known and 2 novel sequence types (STs), suggesting that the institution's C. difficile strains are genetically diverse. ST-1 (which corresponds to pulsed-field gel electrophoresis strain type NAP1/ribotype 027) was the most prevalent (32.6%); 43.5% of the isolates were binary toxin gene positive, of which 75% were ST-1. All strains were ciprofloxacin resistant and metronidazole susceptible, and 8.3% and 13.0% of the isolates were resistant to clindamycin and tetracycline, respectively. The corresponding resistance loci, including potential novel mutations, were identified from the whole-genome sequencing (WGS) of the resistant strains. Core genome single nucleotide polymorphisms (SNPs) determining the phylogenetic relatedness of the 46 strains recapitulated MLST types and provided greater interstrain differentiation. The disease severity was greatest in patients infected with ST-1 and/or binary gene-positive strains, but genome-wide SNP analysis failed to provide additional associations with CDI severity within the same STs. We conclude that MLST and core genome SNP typing result in the same phylogenetic grouping of the 46 C. difficile strains collected in a single hospital. WGS also has the capacity to differentiate those strains within STs and allows the comparison of strains at the individual gene level and at the whole-genome level.
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Exposing the secrets of two well-known Lactobacillus casei phages, J-1 and PL-1, by genomic and structural analysis. Appl Environ Microbiol 2014; 80:7107-21. [PMID: 25217012 DOI: 10.1128/aem.02771-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteriophage J-1 was isolated in 1965 from an abnormal fermentation of Yakult using Lactobacillus casei strain Shirota, and a related phage, PL-1, was subsequently recovered from a strain resistant to J-1. Complete genome sequencing shows that J-1 and PL-1 are almost identical, but PL-1 has a deletion of 1.9 kbp relative to J-1, resulting in the loss of four predicted gene products involved in immunity regulation. The structural proteins were identified by mass spectrometry analysis. Similarly to phage A2, two capsid proteins are generated by a translational frameshift and undergo proteolytic processing. The structure of gene product 16 (gp16), a putative tail protein, was modeled based on the crystal structure of baseplate distal tail proteins (Dit) that form the baseplate hub in other Siphoviridae. However, two regions of the C terminus of gp16 could not be modeled using this template. The first region accounts for the differences between J-1 and PL-1 gp16 and showed sequence similarity to carbohydrate-binding modules (CBMs). J-1 and PL-1 GFP-gp16 fusions bind specifically to Lactobacillus casei/paracasei cells, and the addition of l-rhamnose inhibits binding. J-1 gp16 exhibited a higher affinity than PL-1 gp16 for cell walls of L. casei ATCC 27139 in phage adsorption inhibition assays, in agreement with differential adsorption kinetics observed for both phages in this strain. The data presented here provide insights into how Lactobacillus phages interact with their hosts at the first steps of infection.
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Pleiotropic role of the RNA chaperone protein Hfq in the human pathogen Clostridium difficile. J Bacteriol 2014; 196:3234-48. [PMID: 24982306 DOI: 10.1128/jb.01923-14] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Clostridium difficile is an emergent human pathogen and the most common cause of nosocomial diarrhea. Our recent data strongly suggest the importance of RNA-based mechanisms for the control of gene expression in C. difficile. In an effort to understand the function of the RNA chaperone protein Hfq, we constructed and characterized an Hfq-depleted strain in C. difficile. Hfq depletion led to a growth defect, morphological changes, an increased sensitivity to stresses, and a better ability to sporulate and to form biofilms. The transcriptome analysis revealed pleiotropic effects of Hfq depletion on gene expression in C. difficile, including genes encoding proteins involved in sporulation, stress response, metabolic pathways, cell wall-associated proteins, transporters, and transcriptional regulators and genes of unknown function. Remarkably, a great number of genes of the regulon dependent on sporulation-specific sigma factor, SigK, were upregulated in the Hfq-depleted strain. The altered accumulation of several sRNAs and interaction of Hfq with selected sRNAs suggest potential involvement of Hfq in these regulatory RNA functions. Altogether, these results suggest the pleiotropic role of Hfq protein in C. difficile physiology, including processes important for the C. difficile infection cycle, and expand our knowledge of Hfq-dependent regulation in Gram-positive bacteria.
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Eckert C, Jones G, Barbut F. Diagnosis of Clostridium difficile infection: the molecular approach. Future Microbiol 2014; 8:1587-98. [PMID: 24266358 DOI: 10.2217/fmb.13.129] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Diagnosis of Clostridium difficile infection is based on clinical presentation and laboratory tests. Although numerous laboratory methods are now available, the diagnosis of C. difficile infection remains challenging. Nucleic acid amplification tests (NAATs) are the most recent marketed methods. These methods detect genes for toxins A and/or B. They are very sensitive compared with the reference method (toxigenic culture) and are thus very promising, despite their cost. However, a positive NAAT result must be interpreted with caution owing to the possible detection of asymptomatic carriers of toxigenic strains who may have diarrhea for other reasons. The place of NAATs in current diagnostic strategies needs to be better defined, but the rapidity of the result is interesting for early recognition of the disease.
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Affiliation(s)
- Catherine Eckert
- National Reference Laboratory for Clostridium difficile, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France
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Gilbreath JJ, Verma P, Abbott AN, Butler-Wu SM. Comparison of the Verigene Clostridium difficile, Simplexa C. difficile Universal Direct, BD MAX Cdiff, and Xpert C. difficile assays for the detection of toxigenic C. difficile. Diagn Microbiol Infect Dis 2014; 80:13-8. [PMID: 25027069 DOI: 10.1016/j.diagmicrobio.2014.06.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/31/2014] [Accepted: 06/02/2014] [Indexed: 01/05/2023]
Abstract
We compared the Verigene Clostridium difficile test (Nanosphere, Northbrook, IL, USA), the Simplexa C. difficile Universal Direct (Focus Diagnostics, Cypress, CA, USA), the BD MAX Cdiff (Becton Dickinson, Franklin Lakes, NJ, USA), and the Xpert C. difficile (Cepheid, Sunnyvale, CA, USA) assays for the detection of toxigenic C. difficile. One hundred and ninety deidentified, remnant diarrheal specimens were included in this study. After resolution of discordant results by toxigenic culture, the Xpert C. difficile assay displayed the highest sensitivity (100%), with a specificity of 98.8%. The sensitivity and specificity were 95.2% and 99.4% and 87% and 100% for the Verigene CDF and Simplexa Universal Direct assays, respectively. Finally, the BD MAX assay showed a sensitivity of 87% and a specificity of 98.8%. Despite differences in the overall performance of these assays, these results support the routine use of these platforms for the detection of toxigenic C. difficile in the clinical laboratory.
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Affiliation(s)
- Jeremy J Gilbreath
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98195
| | - Punam Verma
- Department of Pathology and Clinical Laboratories, Virginia Mason Medical Center, Seattle, WA 98101
| | - April N Abbott
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98195
| | - Susan M Butler-Wu
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98195.
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Valiente E, Cairns M, Wren B. The Clostridium difficile PCR ribotype 027 lineage: a pathogen on the move. Clin Microbiol Infect 2014; 20:396-404. [DOI: 10.1111/1469-0691.12619] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Chilton CH, Gharbia SE, Fang M, Misra R, Poxton IR, Borriello SP, Shah HN. Comparative proteomic analysis of Clostridium difficile isolates of varying virulence. J Med Microbiol 2014; 63:489-503. [DOI: 10.1099/jmm.0.070409-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The soluble proteome of three Clostridium difficile strains of varying pathogenic potential, designated B-1, Tra 5/5 and 027 SM, were compared using differential in-gel electrophoresis in which the proteins of each strain were labelled with CyDyes. This enabled visual inspection of the 2D profiles of strains and identification of differentially expressed proteins using image analysis software. Unlabelled protein reference maps of the predominant proteins were then generated for each strain using 2D gel electrophoresis followed by protein sequencing of each spot using a Reflectron matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer. Increased coverage of the proteome was achieved using 1D gel electrophoresis in a bottom-up approach using LC-MS/MS of 1 cm gel slices. A total of 888 different proteins were detected by comparative analysis of isolates grown in parallel for 64 h on blood agar plates. Of these, only 38 % were shared between all isolates. One hundred and ten proteins were identified as showing ≥2-fold difference in expression between strains. Differential expression was shown in a number of potential virulence and colonization factors. Toxin B was detected in the more virulent strains B-1 and 027 SM, but not in the lower virulent strain Tra 5/5, despite all strains possessing an intact pathogenicity locus. The S-layer protein (Cwp2) was identified in strains 027 SM and Tra 5/5 but not strain B-1, and differences in the post-translational modification of SlpA were noted for strain B-1. The variant S-layer profile of strain B-1 was confirmed by genomic comparison, which showed a 58 kb insertion in the S-layer operon of strain B-1. Differential post-translation modification events were also noted in flagellar proteins, thought to be due to differential glycosylation. This study highlights genomic and proteomic variation of different Clostridium difficile strains and suggests a number of factors may play a role in mediating the varying virulence of these different strains.
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Affiliation(s)
- C. H. Chilton
- Leeds Institute for Biomedical and Clinical Sciences, University of Leeds, Leeds LS1 3EX, UK
| | - S. E. Gharbia
- Public Health England, Centre for Infections, London NW9 5EQ, UK
| | - M. Fang
- Public Health England, Centre for Infections, London NW9 5EQ, UK
| | - R. Misra
- Public Health England, Centre for Infections, London NW9 5EQ, UK
| | - I. R. Poxton
- College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - S. P. Borriello
- Veterinary Medicines Directorate, Addlestone, Surrey KT15 3NB, UK
| | - H. N. Shah
- Public Health England, Centre for Infections, London NW9 5EQ, UK
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Jabbari S, Cartman ST, King JR. Mathematical modelling reveals properties of TcdC required for it to be a negative regulator of toxin production in Clostridium difficile. J Math Biol 2014; 70:773-804. [PMID: 24687436 PMCID: PMC4320785 DOI: 10.1007/s00285-014-0780-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 03/05/2014] [Indexed: 01/05/2023]
Abstract
The role of the protein TcdC in pathogenicity of the bacterium Clostridium difficile is currently unclear: conflicting reports suggest it is either a negative regulator of toxin production or, on the other hand, has no effect on virulence at all. We exploit a theoretical approach by taking what is known about the network of proteins surrounding toxin production by C. difficile and translating this into a mathematical model. From there it is possible to investigate a range of possible interactions (using numerical and asymptotic analyses), identifying properties of TcdC which would make it a realistic candidate as a toxin inhibitor. Our findings imply that if TcdC is really an inhibitor of toxin production then TcdC production should be at least as fast as that of the protein TcdR and TcdC should remain in the cells throughout growth. These are experimentally-testable hypotheses and are equally applicable to alternative candidates for toxin production inhibition.
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Affiliation(s)
- Sara Jabbari
- School of Mathematics and Institute of Microbiology and Infection, University of Birmingham, Birmingham, B15 2TT, UK,
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