1
|
Boeriu A, Roman A, Fofiu C, Dobru D. The Current Knowledge on Clostridioides difficile Infection in Patients with Inflammatory Bowel Diseases. Pathogens 2022; 11:pathogens11070819. [PMID: 35890064 PMCID: PMC9323231 DOI: 10.3390/pathogens11070819] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/17/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022] Open
Abstract
Clostridioides difficile (C. difficile) represents a major health burden with substantial economic and clinical impact. Patients with inflammatory bowel diseases (IBD) were identified as a risk category for Clostridioides difficile infection (CDI). In addition to traditional risk factors for C. difficile acquisition, IBD-specific risk factors such as immunosuppression, severity and extension of the inflammatory disease were identified. C. difficile virulence factors, represented by both toxins A and B, induce the damage of the intestinal mucosa and vascular changes, and promote the inflammatory host response. Given the potential life-threatening complications, early diagnostic and therapeutic interventions are required. The screening for CDI is recommended in IBD exacerbations, and the diagnostic algorithm consists of clinical evaluation, enzyme immunoassays (EIAs) or nucleic acid amplification tests (NAATs). An increased length of hospitalization, increased colectomy rate and mortality are the consequences of concurrent CDI in IBD patients. Selection of CD strains of higher virulence, antibiotic resistance, and the increasing rate of recurrent infections make the management of CDI in IBD more challenging. An individualized therapeutic approach is recommended to control CDI as well as IBD flare. Novel therapeutic strategies have been developed in recent years in order to manage severe, refractory or recurrent CDI. In this article, we aim to review the current evidence in the field of CDI in patients with underlying IBD, pointing to pathogenic mechanisms, risk factors for infection, diagnostic steps, clinical impact and outcomes, and specific management.
Collapse
Affiliation(s)
- Alina Boeriu
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
- Gastroenterology Department, Mures County Clinical Hospital, 540103 Targu Mures, Romania
| | - Adina Roman
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
- Gastroenterology Department, Mures County Clinical Hospital, 540103 Targu Mures, Romania
- Correspondence: ; Tel.: +40-752934465
| | - Crina Fofiu
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
| | - Daniela Dobru
- Gastroenterology Department, University of Medicine Pharmacy, Sciences, and Technology “George Emil Palade” Targu Mures, 540142 Targu Mures, Romania; (A.B.); (C.F.); (D.D.)
- Gastroenterology Department, Mures County Clinical Hospital, 540103 Targu Mures, Romania
| |
Collapse
|
2
|
Brajerova M, Zikova J, Krutova M. Clostridioides difficile epidemiology in the Middle and the Far East. Anaerobe 2022; 74:102542. [PMID: 35240336 DOI: 10.1016/j.anaerobe.2022.102542] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 02/14/2022] [Accepted: 02/20/2022] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Clostridioides difficile is an important pathogen of healthcare-associated gastrointestinal infections. Recently, an increased number of C. difficile infection (CDI) surveillance data has been reported from Asia. The aim of this review is to summarize the data on the prevalence, distribution and molecular epidemiology of CDI in the Middle and the Far East. METHODS Literature was drawn from a search of PubMed up to September 30, 2021. RESULTS The meta-analysis of data from 111 studies revealed the pooled CDI prevalence rate in the Middle and the Far East of 12.4% (95% CI 11.4-13.3); 48 studies used PCR for CDI laboratory diagnoses. The predominant types (RT)/sequence type (ST) differ between individual countries (24 studies, 14 countries). Frequently found RTs were 001, 002, 012, 017, 018 and 126; RT017 was predominant in the Far East. The epidemic RT027 was detected in 8 countries (22 studies), but its predominance was reported only in three studies (Israel and Iran). The contamination of vegetable and meat or meat products and/or intestinal carriage of C. difficile in food and companion animals have been reported; the C. difficile RTs/STs identified overlapped with those identified in humans. CONCLUSIONS A large number of studies on CDI prevalence in humans from the Middle and the Far East have been published; countries with no available data were identified. The number of studies on C. difficile from non-human sources is limited. Comparative genomic studies of isolates from different sources are needed.
Collapse
Affiliation(s)
- Marie Brajerova
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Czech Republic
| | - Jaroslava Zikova
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Czech Republic; Department of Genetics and Microbiology, Faculty of Science, Charles University, Czech Republic
| | - Marcela Krutova
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Czech Republic.
| |
Collapse
|
3
|
Ressler A, Wang J, Rao K. Defining the black box: a narrative review of factors associated with adverse outcomes from severe Clostridioides difficile infection. Therap Adv Gastroenterol 2021; 14:17562848211048127. [PMID: 34646358 PMCID: PMC8504270 DOI: 10.1177/17562848211048127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/31/2021] [Indexed: 02/04/2023] Open
Abstract
In the United States, Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated infection, affecting nearly half a million people and resulting in more than 20,000 in-hospital deaths every year. It is therefore imperative to better characterize the intricate interplay between C. difficile microbial factors, host immunologic signatures, and clinical features that are associated with adverse outcomes of severe CDI. In this narrative review, we discuss the implications of C. difficile genetics and virulence factors in the molecular epidemiology of CDI, and the utility of early biomarkers in predicting the clinical trajectory of patients at risk of developing severe CDI. Furthermore, we identify associations between host immune factors and CDI outcomes in both animal models and human studies. Next, we highlight clinical factors including renal dysfunction, aging, blood biomarkers, level of care, and chronic illnesses that can affect severe CDI diagnosis and outcome. Finally, we present our perspectives on two specific treatments pertinent to patient outcomes: metronidazole administration and surgery. Together, this review explores the various venues of CDI research and highlights the importance of integrating microbial, host, and clinical data to help clinicians make optimal treatment decisions based on accurate prediction of disease progression.
Collapse
Affiliation(s)
- Adam Ressler
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Joyce Wang
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | | |
Collapse
|
4
|
Mutai WC, Mureithi MW, Anzala O, Revathi G, Kullin B, Burugu M, Kyany'a C, Odoyo E, Otieno P, Musila L. High Prevalence of Multidrug-Resistant Clostridioides difficile Following Extensive Use of Antimicrobials in Hospitalized Patients in Kenya. Front Cell Infect Microbiol 2021; 10:604986. [PMID: 33628744 PMCID: PMC7897694 DOI: 10.3389/fcimb.2020.604986] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/14/2020] [Indexed: 01/02/2023] Open
Abstract
Introduction Clostridioides difficile is a neglected pathogen in many African countries as it is generally not regarded as one of the major contributors toward the diarrheal disease burden in the continent. However, several studies have suggested that C. difficile infection (CDI) may be underreported in many African settings. The aim of this study was to determine the prevalence of CDI in hospitalized patients, evaluate antimicrobial exposure, and detect toxin and antimicrobial resistance profiles of the isolated C. difficile strains. Methods In this cross-sectional study, 333 hospitalized patients with hospital-onset diarrhoea were selected. The stool samples were collected and cultured on cycloserine-cefoxitin egg yolk agar (CCEY). Isolates were presumptively identified by phenotypic characteristics and Gram stain and confirmed by singleplex real-time PCR (qPCR) assays detecting the species-specific tpi gene, toxin A (tcdA) gene, toxin B (tcdB) gene, and the binary toxin (cdtA/cdtB) genes. Confirmed C. difficile isolates were tested against a panel of eight antimicrobials (vancomycin, metronidazole, rifampicin, ciprofloxacin, tetracycline, clindamycin, erythromycin, and ceftriaxone) using E-test strips. Results C. difficile was detected in 57 (25%) of diarrheal patients over the age of two, 56 (98.2%) of whom received antimicrobials before the diarrheal episode. Amongst the 71 confirmed isolates, 69 (97.1%) harbored at least one toxin gene. More than half of the toxigenic isolates harbored a truncated tcdA gene. All isolates were sensitive to vancomycin, while three isolates (2.1%) were resistant to metronidazole (MIC >32 mg/L). High levels of resistance were observed to rifampicin (65/71, 91.5%), erythromycin (63/71, 88.7%), ciprofloxacin (59/71, 83.1%), clindamycin (57/71, 80.3%), and ceftriaxone (36/71, 50.7.8%). Among the resistant isolates, 61 (85.9%) were multidrug-resistant. Conclusion Multidrug-resistant C. difficile strains were a significant cause of healthcare facility-onset C. difficile infections in patients with prior antimicrobial exposure in this Kenyan hospital.
Collapse
Affiliation(s)
- Winnie C Mutai
- Department of Medical Microbiology, School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Marianne W Mureithi
- Department of Medical Microbiology, School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Omu Anzala
- Department of Medical Microbiology, School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Gunturu Revathi
- Department of Pathology, Division of Medical Microbiology, Aga Khan University Hospital, Nairobi, Kenya
| | - Brian Kullin
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| | - Magdaline Burugu
- Department of Medical Microbiology, School of Medicine, University of Nairobi, Nairobi, Kenya
| | | | - Erick Odoyo
- US Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Peter Otieno
- US Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Lillian Musila
- US Army Medical Research Directorate-Africa, Nairobi, Kenya
| |
Collapse
|
5
|
Dayananda P, Wilcox MH. A Review of Mixed Strain Clostridium difficile Colonization and Infection. Front Microbiol 2019; 10:692. [PMID: 31024483 PMCID: PMC6469431 DOI: 10.3389/fmicb.2019.00692] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 03/19/2019] [Indexed: 12/18/2022] Open
Abstract
Given that Clostridium difficile is not part of the normal human microbiota, if multiple strains are to accumulate in the colon implies successive exposure events and/or persistent colonization must occur. Evidence of C. difficile infection (CDI) with more than one strain was first described in 1983. Despite the availability of increasingly discriminatory bacterial fingerprinting methods, the described rate of dual strain recovery in patients with CDI has remained stable at ∼5–10%. More data are needed to determine when dual strain infection may be harmful. Notably, one strain may block the establishment of and infection by another. In humans, patients colonized by non-toxigenic C. difficile strain are at a lower risk of developing CDI. Further studies to elucidate the interaction between co-infecting or colonizing and infecting C. difficile strains may help identify potential exploitable mechanisms to prevent CDI.
Collapse
Affiliation(s)
- Pete Dayananda
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.,Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, United Kingdom
| | - Mark H Wilcox
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.,Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
6
|
MOHAMMADBEIGI M, SAFAYI DELOUYI Z, MOHAMMADZADEH N, ALA’ALMOHADESIN A, TAHERI K, EDALATI E, SEDIGHI M, ZAHEDI BIALVAEI A. Prevalence and antimicrobial susceptibility pattern of toxigenic Clostridium difficilestrains isolated in Iran. Turk J Med Sci 2019; 49:384-391. [PMID: 30761842 PMCID: PMC7350832 DOI: 10.3906/sag-1808-11] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background/aim Clostridium difficile is a frequent cause of nosocomial infections and has become a major public health concern in developed nations. In the present study, the prevalence and antimicrobial susceptibility pattern of toxigenic C. difficile strains isolated in Iran were investigated. Materials and methods Between June 2016 and May 2017, 2947 inpatient fecal samples were taken from symptomatic adult hospitalized patients in different units of 32 care facilities in Tehran, Iran. C. difficile strains were identified by microbiological/biochemical methods. Susceptibility to 20 antimicrobials was measured by E-test method. Toxin-specific immunoassays and cytotoxicity assays were used to determine in vitro toxin production. Results Out of 2947 fecal samples, 538 (18.25%) C. difficile isolates were obtained among those with suspected CDI. In E-test method, all C. difficile isolates were susceptible to fidaxomicin, vancomycin, amoxicillin/clavulanate, and meropenem and were resistant to penicillin G. The prevalence of multidrug resistant C. difficile was 69.33% (373/538). Among 538 C. difficile, 147 (27.32%), 169 (31.41%), and 222 (41.26%) isolates were TcdA+/TcdB+, TcdA-/TcdB+, and TcdA-/TcdB-, respectively. Conclusion The results evidently support the hypothesis of a probable role of toxigenic strains of C. difficile in developing gastrointestinal complaints in patients with diarrhea.
Collapse
Affiliation(s)
- Maryam MOHAMMADBEIGI
- Department of Microbiology and Immunology, Qazvin University of Medical Sciences, QazvinIran
| | - Zahra SAFAYI DELOUYI
- Department of Microbiology, School of Basic Sciences, Qom Branch, Islamic Azad University, QomIran
| | - Nima MOHAMMADZADEH
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, TehranIran
| | - Arash ALA’ALMOHADESIN
- Department of Microbiology, School of Basic Sciences, Qom Branch, Islamic Azad University, QomIran
| | - Keyvan TAHERI
- Department of Biology, Damghan Branch, Islamic Azad University, DamghanIran
| | - Elahe EDALATI
- Department of Microbiology, Kerman Branch, Islamic Azad University, KermanIran
| | - Mansour SEDIGHI
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, TehranIran
- Azarbaijan-Gharbi Regional Blood Transfusion Center, UrmiaIran
| | - Abed ZAHEDI BIALVAEI
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, TehranIran
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|
7
|
Kullin BR, Reid S, Abratt V. Clostridium difficile in patients attending tuberculosis hospitals in Cape Town, South Africa, 2014-2015. Afr J Lab Med 2018; 7:846. [PMID: 30568907 PMCID: PMC6295828 DOI: 10.4102/ajlm.v7i2.846] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/28/2018] [Indexed: 01/05/2023] Open
Abstract
Background Diarrhoea due to Clostridium difficile infection (CDI) poses a significant burden on healthcare systems around the world. However, there are few reports on the current status of the disease in sub-Saharan Africa. Objectives This study examined the occurrence of CDI in a South African population of tuberculosis patients, as well as the molecular epidemiology and antibiotic susceptibility profiles of C. difficile strains responsible for disease. Methods Toxigenic C. difficile in patients with suspected CDI attending two specialist tuberculosis hospitals in the Cape Town area were detected using a PCR-based diagnostic assay (Xpert® C. difficile). C. difficile strains isolated from PCR-positive specimens were characterised by ribotyping, multilocus variable-number tandem-repeat analysis and antibiotic susceptibility testing. Results The period prevalence of CDI was approximately 70.07 cases per 1000 patient admissions. Strains belonging to ribotype 017 (RT017) made up over 95% of the patient isolates and all of them were multi-drug resistant. Multilocus variable-number tandem-repeat analysis revealed several clusters of highly related C. difficile RT017 strains present in tuberculosis patients in several wards at each hospital. Conclusion Tuberculosis patients represent a population that may be at an increased risk of developing CDI and, in addition, may constitute a multi-drug resistant reservoir of this bacterium. This warrants further investigation and surveillance of the disease in this patient group and other high-risk patient groups in sub-Saharan Africa.
Collapse
Affiliation(s)
- Brian R Kullin
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| | - Sharon Reid
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| | - Valerie Abratt
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| |
Collapse
|
8
|
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.
Collapse
|
9
|
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.
Collapse
|
10
|
Di Bella S, Ascenzi P, Siarakas S, Petrosillo N, di Masi A. Clostridium difficile Toxins A and B: Insights into Pathogenic Properties and Extraintestinal Effects. Toxins (Basel) 2016; 8:E134. [PMID: 27153087 PMCID: PMC4885049 DOI: 10.3390/toxins8050134] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile infection (CDI) has significant clinical impact especially on the elderly and/or immunocompromised patients. The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight junctions of target cells causing cell rounding and ultimately cell death. Detectable C. difficile toxemia is strongly associated with fulminant disease. However, besides the well-known intestinal damage, recent animal and in vitro studies have suggested a more far-reaching role for these toxins activity including cardiac, renal, and neurologic impairment. The creation of C. difficile strains with mutations in the genes encoding toxin A and B indicate that toxin B plays a major role in overall CDI pathogenesis. Novel insights, such as the role of a regulator protein (TcdE) on toxin production and binding interactions between albumin and C. difficile toxins, have recently been discovered and will be described. Our review focuses on the toxin-mediated pathogenic processes of CDI with an emphasis on recent studies.
Collapse
Affiliation(s)
- Stefano Di Bella
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
| | - Paolo Ascenzi
- Department of Science, Roma Tre University, Rome 00154, Italy.
| | - Steven Siarakas
- Department of Microbiology and Infectious Diseases, Concord Repatriation General Hospital, Sydney 2139, Australia.
| | - Nicola Petrosillo
- 2nd Infectious Diseases Division, National Institute for Infectious Diseases "L. Spallanzani", Rome 00149, Italy.
| | | |
Collapse
|
11
|
Genomic Epidemiology of a Protracted Hospital Outbreak Caused by a Toxin A-Negative Clostridium difficile Sublineage PCR Ribotype 017 Strain in London, England. J Clin Microbiol 2015; 53:3141-7. [PMID: 26179308 PMCID: PMC4572532 DOI: 10.1128/jcm.00648-15] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/17/2015] [Indexed: 12/26/2022] Open
Abstract
Clostridium difficile remains the leading cause of nosocomial diarrhea worldwide, which is largely considered to be due to the production of two potent toxins: TcdA and TcdB. However, PCR ribotype (RT) 017, one of five clonal lineages of human virulent C. difficile, lacks TcdA expression but causes widespread disease. Whole-genome sequencing was applied to 35 isolates from hospitalized patients with C. difficile infection (CDI) and two environmental ward isolates in London, England. The phylogenetic analysis of single nucleotide polymorphisms (SNPs) revealed a clonal cluster of temporally variable isolates from a single hospital ward at University Hospital Lewisham (UHL) that were distinct from other London hospital isolates. De novo assembled genomes revealed a 49-kbp putative conjugative transposon exclusive to this hospital clonal cluster which would not be revealed by current typing methodologies. This study identified three sublineages of C. difficile RT017 that are circulating in London. Similar to the notorious RT027 lineage, which has caused global outbreaks of CDI since 2001, the lineage of toxin-defective RT017 strains appears to be continually evolving. By utilization of WGS technologies to identify SNPs and the evolution of clonal strains, the transmission of outbreaks caused by near-identical isolates can be retraced and identified.
Collapse
|
12
|
Cairns MD, Stabler RA, Shetty N, Wren BW. The continually evolving Clostridium difficile species. Future Microbiol 2013; 7:945-57. [PMID: 22913354 DOI: 10.2217/fmb.12.73] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Clostridium difficile is a spore-forming Gram-positive bacterium that causes chronic diarrhea and sometimes life-threatening disease mainly in elderly and hospitalized patients. The reported incidence of C. difficile infection has changed dramatically over the last decade and has been related to the emergence of distinct clonal lineages that appear more transmissible and cause more severe infection. These include PCR ribotypes 027, 017 and more recently 078. Population biology studies using multilocus sequence typing and whole-genome comparisons has helped to define the C. difficile species into four clonal complexes that include PCR ribotypes 027, 017, 078 and 023, as well as a general grouping of most other PCR ribotypes. Further analysis of strains from diverse sources and geographical origins reveal significant microdiversity of clonal complexes and confirms that C. difficile is continuing to evolve. The study of C. difficile represents a real-time global evolutionary experiment where the pathogen is responding to a range of selective pressures created by human activity and practices in healthcare settings. The advent of whole-genome sequencing coupled with phylogeny (phylogeography and phylohistory) will provide unprecedented detail on the local and global emergence and disappearance of C. difficile clones, and facilitate more rational approaches to disease control. This review will highlight the emergence of virulent C. difficile clones and our current understanding of molecular epidemiology of the species.
Collapse
Affiliation(s)
- Michelle D Cairns
- Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | | | | | | |
Collapse
|
13
|
Predrag S, Branislava K, Miodrag S, Biljana MS, Suzana T, Natasa MT, Tatjana B. Clinical importance and representation of toxigenic and non-toxigenic Clostridium difficile cultivated from stool samples of hospitalized patients. Braz J Microbiol 2012; 43:215-23. [PMID: 24031820 PMCID: PMC3768987 DOI: 10.1590/s1517-838220120001000023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 03/18/2011] [Accepted: 08/30/2011] [Indexed: 02/04/2023] Open
Abstract
The aim of this study was to fortify the clinical importance and representation of toxigenic and non-toxigenic Clostridium difficile isolated from stool samples of hospitalized patients. This survey included 80 hospitalized patients with diarrhea and positive findings of Clostridium difficile in stool samples, and 100 hospitalized patients with formed stool as a control group. Bacteriological examination of a stool samples was conducted using standard microbiological methods. Stool sample were inoculated directly on nutrient media for bacterial cultivation (blood agar using 5% sheep blood, Endo agar, selective Salmonella Shigella agar, Selenite-F broth, CIN agar and Skirrow's medium), and to selective cycloserine-cefoxitin-fructose agar (CCFA) (Biomedics, Parg qe tehnicologico, Madrid, Spain) for isolation of Clostridium difficile. Clostridium difficile toxin was detected by ELISA-ridascreen Clostridium difficile Toxin A/B (R-Biopharm AG, Germany) and ColorPAC ToxinA test (Becton Dickinson, USA). Examination of stool specimens for the presence of parasites (causing diarrhea) was done using standard methods (conventional microscopy), commercial concentration test Paraprep S Gold kit (Dia Mondial, France) and RIDA(®)QUICK Cryptosporidium/Giardia Combi test (R-Biopharm AG, Germany). Examination of stool specimens for the presence of fungi (causing diarrhea) was performed by standard methods. All stool samples positive for Clostridium difficile were tested for Rota, Noro, Astro and Adeno viruses by ELISA - ridascreen (R-Biopharm AG, Germany). In this research we isolated 99 Clostridium difficile strains from 116 stool samples of 80 hospitalized patients with diarrhea. The 53 (66.25%) of patients with diarrhea were positive for toxins A and B, one (1.25%) were positive for only toxin B. Non-toxigenic Clostridium difficile isolated from samples of 26 (32.5%) patients. However, other pathogenic microorganisms of intestinal tract cultivated from samples of 16 patients. Examination of cultivated colonies revealed that most of cultivated species belonged to genera of Campylobacter spp., Salmonella spp., and Candida spp.. In control group, toxigenic Clostridium difficile cultivated from stool samples of two patients (2%) and non-toxigenic Clostridium difficile from samples of five patients (5%). This research confirmed clinical importance of toxigenic Clostridium difficile found in liquid stool samples of hospitalized patient, and the possibility of asymptomatic carriage in 2% of patients with formed stool.
Collapse
Affiliation(s)
- Stojanovic Predrag
- Faculty of Medicine, University of Nis , Serbia ; Institute for Public Health Nis, Center of Microbiology , Serbia
| | | | | | | | | | | | | |
Collapse
|
14
|
Jamal W, Rotimi VO, Brazier J, Duerden BI. Analysis of prevalence, risk factors and molecular epidemiology of Clostridium difficile infection in Kuwait over a 3-year period. Anaerobe 2010; 16:560-5. [PMID: 20887795 DOI: 10.1016/j.anaerobe.2010.09.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 09/21/2010] [Accepted: 09/22/2010] [Indexed: 01/22/2023]
Abstract
We conducted a prospective study to evaluate the prevalence and epidemiology of CDI in Kuwait government hospitals over a 3-year period, January 2003 to December 2005, to determine the ribotypes responsible for CDI and to estimate the prevalence of ribotype 027. We also conducted a case-control study to identify the risk factors in our patient population. A total of 697 stool samples from patients with suspected CDI were obtained and sent to Anaerobe Reference Laboratory, Faculty of Medicine, Kuwait University for Clostridium difficile toxin detection, culture and PCR ribotyping. During the period, 73 (10.5%) out of 697 patients met the case definition of CDI. Of these, 56 (76.7%) were hospital-acquired and 17 (23.3%) were from outpatient clinics. Thus, the prevalence of hospital-acquired CDI amongst patients with diarrhoea was 8% over the study period; the prevalence in 2003, 2004 and 2005 was 9.7%, 7.8% and 7.2%, respectively. Our data showed that 42.9% of the CDI patients were above 60 years, of which >79% were aged 71 years and above. Patients with CDI were more likely than the controls to have been exposed to immunosuppressive drugs and feeding via nasogastric tube. The most common ribotypes isolated during this study were 002, 001, 126 and 140 and they represent 55.1% of all isolates. PCR ribotype 027 was not isolated.
Collapse
Affiliation(s)
- W Jamal
- Department of Microbiology, Kuwait University, Safat, Kuwait.
| | | | | | | |
Collapse
|
15
|
Abstract
Clostridium difficile has re-emerged as a major hospital-acquired infection since 2001. Despite development of polymerase chain reaction-based testing, no single clinical diagnostic test has emerged with sufficient sensitivity, specificity, and turnaround time to be entirely reliable for disease diagnosis. The importance of C difficile acquired outside the hospital environment remains an unknown factor and awaits further epidemiologic investigation. This article discusses the changing epidemiology, clinical presentation, and pathogenesis of C difficile infection and highlights the ongoing challenges of laboratory diagnosis, treatment, and disease relapse.
Collapse
|
16
|
Evaluation of tcdB real-time PCR in a three-step diagnostic algorithm for detection of toxigenic Clostridium difficile. J Clin Microbiol 2009; 48:124-30. [PMID: 19923482 DOI: 10.1128/jcm.00734-09] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile is the most common infectious cause of diarrhea in hospitalized patients. The optimal approach for the detection of toxigenic C. difficile remains controversial because no single test is sensitive, specific, and affordable. We have developed a real-time PCR method (direct stool PCR [DPCR]) to detect the tcdB gene encoding toxin B directly from stool specimens and have combined it with enzyme immunoassays (EIAs) in a three-step protocol. DPCR was performed on 699 specimens that were positive for C. difficile glutamate dehydrogenase (GDH) by Wampole C Diff Quik Chek EIA (GDH-Q) and negative for toxins A and B by Wampole Tox A/B Quik Chek EIA (AB-Q), performed sequentially. The performance of this three-step algorithm was compared with a modified "gold standard" that combined tissue culture cytotoxicity (CYT) and DPCR. A separate investigation was performed to evaluate the sensitivity of the GDH-Q as a screening test, and toxigenic C. difficile was found in 1.9% of 211 GDH-Q-negative specimens. The overall sensitivity, specificity, and positive and negative predictive values, respectively, were as follows for an algorithm combining GDH-Q, AB-Q, and DPCR: 83.8%, 99.7%, 97.1%, and 97.9%. Those for CYT alone were 58.8%, 100%, 100%, and 94.9%, respectively. In comparison, the sensitivity and specificity of DPCR were estimated to be 97.5% and 99.7%, respectively, using the same modified gold standard. Neither CYT nor toxin EIA was sufficiently sensitive to exclude toxigenic C. difficile, and combining EIAs with CYT in a three-step algorithm failed to substantially improve sensitivity. DPCR is a sensitive and specific method for the detection of toxigenic C. difficile that can provide same-day results at a cost-per-positive test comparable to those of other methods. A three-step algorithm in which DPCR is used to analyze GDH EIA-positive, toxin EIA-negative specimens provides a convenient and specific alternative with rapid results for 87.7% of specimens, although this approach is less sensitive than performing DPCR on all specimens.
Collapse
|
17
|
Shin BM, Yoo SJ, Oh HJ. [Comparison of two enzyme immunoassay for detection of Clostridium difficile toxin A and toxin B]. Korean J Lab Med 2009; 29:122-6. [PMID: 19411778 DOI: 10.3343/kjlm.2009.29.2.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Enzyme immunoassay (EIA) capable of detecting both toxin A and toxin B is strongly recommended for the diagnosis of Clostridium difficile associated disease. Therefore, we evaluated two different EIAs for the detection of C. difficile toxin A/B. METHODS For a total of 228 stool specimens we performed bacteriologic cultures for C. difficile and examined for toxin A and toxin B using enzyme linked fluorescent immunoassay (ELFA; VIDAS CDAB, Bio-Merieux sa, France) and ELISA (C.DIFFICILE TOX A/B II, TECHLAB, USA). We also performed PCR assays for toxin A and B genes in 117 C. difficile isolates that grew from the stool cultures and compared the results with those obtained with the two different EIAs. RESULTS The concordance rate between ELFA and ELISA was 85.5% (195/228). Using the culture and PCR results as the standard, the sensitivity/specificity of the ELFA and ELISA were 65.0%/72.1% and 71.8%/70.3%, and for positive/negative predictive values were 78.4%/69.6% and 71.8%/70.3%, respectively (P value >0.05). No differences were observed between the results of ELFA and ELISA with toxin A(-) toxin B(+) strains of C. difficile. CONCLUSIONS The sensitivity of the ELISA was slightly higher than that of ELFA for toxin A and toxin B, but the specificity and positive predictive value of the ELFA were rather higher than those of the ELISA, although no statistical differences were observed. A bacteriologic culture and PCR assay for toxin genes are recommended in case the both EIAs are negative.
Collapse
Affiliation(s)
- Bo-Moon Shin
- Department of Laboratory Medicine, Sanggye Paik Hospital, Inje University, Nowon-gu, Seoul, Korea.
| | | | | |
Collapse
|
18
|
Nemat H, Khan R, Ashraf MS, Matta M, Ahmed S, Edwards BT, Hussain R, Lesser M, Pekmezaris R, Dlugacz Y, Wolf-Klein G. Diagnostic value of repeated enzyme immunoassays in Clostridium difficile infection. Am J Gastroenterol 2009; 104:2035-41. [PMID: 19367273 DOI: 10.1038/ajg.2009.174] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES There has been a significant increase in the prevalence, severity, and mortality of Clostridium difficile infection (CDI), with an estimated three million new cases per year in the United States. Yet diagnosing CDI remains problematic. The most commonly used test is stool enzyme immunoassay (EIA) detecting toxin A and/or B, but there are no clear guidelines specifying the optimal number of tests to be ordered in the diagnostic workup, although multiple tests are frequently ordered. Thus, we designed a study with the primary objective of evaluating the diagnostic utility of repeat second and third tests of stool EIA detecting both toxins A and B (EIA (A&B)) in cases with negative initial samples, and sought to describe the physicians' patterns of ordering this test in the workup of suspected CDI. METHODS A retrospective study was carried out using a database of all stool EIA (A&B) tests ordered for a presumptive diagnosis of CDI. All patients were adults admitted to a major teaching hospital over a three-and-a-half-year period (tests completed within 5 days of ordering the first test were grouped into a single episode, and only the first three samples per episode were analyzed). Age, gender, and results of stool EIA were tabulated. In addition, physicians' ordering patterns and proportion of positive stools relative to the number of tests ordered were also analyzed. A single positive EIA result was interpreted as evidence for the clinical presence of CDI. RESULTS A total of 3,712 patients contributed to 5,865 separate diarrhea episodes (total stool EIA (A&B)=9,178), and 1,165 (19.9%) of these episodes were positive for CDI. Of the positive patients, 73.2% were over the age of 65 years and 54.2% of them were females. The most frequent ordering pattern for presumptive CDI was a single stool test (60.1%), followed by two more tests (23.2%). Three tests were still ordered in 16.6% of the cases. Of the 1,165 positive cases, 1,046 (89.8%) were diagnosed in the very first test, 95 (8.2%) in the second, and only 24 (2.0%) in the third test. In 1,934 instances, a second test was ordered after an initial negative result, of which 95 (4.91%) became positive. In 793 episodes, a third test was ordered after two negative samples, of which only 24 (3.03%) became positive. CONCLUSIONS This study highlights the low diagnostic yield of repeat stool EIA (A&B) testing. Findings strongly support the utility of limiting the workup of suspected CDI to a single stool test with only one repeat test in cases of high clinical suspicion, and avoiding the routine ordering of multiple stool samples. As Clostridium difficile is becoming an endemic health-care problem resulting in major financial burdens for the US health-care system, clear guidelines specifying the optimal number of stool EIA (A&B) tests to be ordered in the diagnostic workup of suspected CDI must be established to assist physicians in the practice of evidence-based medicine.
Collapse
Affiliation(s)
- Hashim Nemat
- Long Island Jewish Medical Center, New Hyde Park, New York 11040, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Algorithm combining toxin immunoassay and stool culture for diagnosis of Clostridium difficile infection. J Clin Microbiol 2009; 47:2952-6. [PMID: 19625481 DOI: 10.1128/jcm.00609-09] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enzyme immunoassays (EIA) to detect glutamate dehydrogenase or toxins A (TcdA) and B (TcdB), a cytotoxicity assay, and bacteriologic culture have disadvantages when applied individually to diagnosis of Clostridium difficile infections. Stool specimens (n = 1,596) were subjected to toxin detection via an enzyme-linked fluorescent immunoassay (ELFA; Vidas CDAB assay) and bacteriologic culture for toxigenic C. difficile in a three-step algorithm with additional toxigenic culture. Isolates (n = 163) from ELFA-negative stool specimens were examined via ELFA for toxin production. We amplified tcdA and tcdB from C. difficile isolates and tcdB from stool specimens that were ELFA positive or equivocal and culture negative, and we compared the results to those obtained with the three-step algorithm. More than 26% of stool specimens (419/1,596) were culture positive, yielding 248 isolates (59.2%) with both toxin genes (tcdA- and tcdB-positive isolates), 88 isolates (21.0%) with either tcdA or tcdB, and 83 (19.8%) that had no toxin genes (tcdA- and tcdB-negative isolates). Among 49 (culture-negative/ELFA-positive or -equivocal) stool specimens, 53.1% (26/49) represented tcdB-positive isolates. Therefore, the total number of PCR-positive cases was 362, and 27.1% (98/362) of these were detected through toxigenic culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 63.3%, 96.7%, 90.5%, and 92.4% (ELFA alone); 92.8%, 93.3%, 80.2%, and 97.8% (culture); and 70.7%, 91.4%, 95.5%, and 100% (three-step algorithm ELFA and bacterial culture with toxigenic culture), respectively, with culture and PCR for tcdA and tcdB as the standards. Thus, sensitivity and specificity were highest using culture and ELFA, respectively, but we recommend the three-step algorithm comprising EIA to detect both toxins and toxigenic culture for C. difficile as a practical method for achieving better PPV and NPV.
Collapse
|
20
|
Human alpha-defensins inhibit hemolysis mediated by cholesterol-dependent cytolysins. Infect Immun 2009; 77:4028-40. [PMID: 19581399 DOI: 10.1128/iai.00232-09] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Many pathogenic gram-positive bacteria release exotoxins that belong to the family of cholesterol-dependent cytolysins. Here, we report that human alpha-defensins HNP-1 to HNP-3 acted in a concentration-dependent manner to protect human red blood cells from the lytic effects of three of these exotoxins: anthrolysin O (ALO), listeriolysin O, and pneumolysin. HD-5 was very effective against listeriolysin O but less effective against the other toxins. Human alpha-defensins HNP-4 and HD-6 and human beta-defensin-1, -2, and -3 lacked protective ability. HNP-1 required intact disulfide bonds to prevent toxin-mediated hemolysis. A fully linearized analog, in which all six cysteines were replaced by aminobutyric acid (Abu) residues, showed greatly reduced binding and protection. A partially unfolded HNP-1 analog, in which only cysteines 9 and 29 were replaced by Abu residues, showed intact ALO binding but was 10-fold less potent in preventing hemolysis. Surface plasmon resonance assays revealed that HNP-1 to HNP-3 bound all three toxins at multiple sites and also that solution-phase HNP molecules could bind immobilized HNP molecules. Defensin concentrations that inhibited hemolysis by ALO and listeriolysin did not prevent these toxins from binding either to red blood cells or to cholesterol. Others have shown that HNP-1 to HNP-3 inhibit lethal toxin of Bacillus anthracis, toxin B of Clostridium difficile, diphtheria toxin, and exotoxin A of Pseudomonas aeruginosa; however, this is the first time these defensins have been shown to inhibit pore-forming toxins. An "ABCDE mechanism" that can account for the ability of HNP-1 to HNP-3 to inhibit so many different exotoxins is proposed.
Collapse
|
21
|
Shin BM, Kuak EY, Yoo HM, Kim EC, Lee K, Kang JO, Whang DH, Shin JH. Multicentre study of the prevalence of toxigenic Clostridium difficile in Korea: results of a retrospective study 2000-2005. J Med Microbiol 2008; 57:697-701. [PMID: 18480325 DOI: 10.1099/jmm.0.47771-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The prevalence of toxigenic Clostridium difficile in Korea has been reported to be approximately 60-80%. Although the prevalence of the tcdA(-)tcdB(+) C. difficile strain was less then 5% prior to the year 2000, it has become an emerging nosocomial pathogen in Korea. Therefore, we have attempted to determine the multicentre nationwide prevalence of tcdA(+)tcdB(+) and tcdA(-)tcdB(+) C. difficile for epidemiological purposes. C. difficile strains (n=724, 30 from 2000, 80 from 2001, 74 from 2002, 76 from 2003, 179 from 2004, 285 from 2005) were obtained retrospectively from January 2000 to December 2005 from in-patients at 6 hospitals, all of whom were suspected of having C. difficile-associated disease (CDAD), colitis or pseudomembranous colitis. The numbers of participating hospitals varied yearly (1 in 2000, 2 in 2001-2003, 3 in 2004, 5 in 2005). The hospitals were located in Seoul (n=4), Kyunggi Province (n=1) and Busan (n=1), Korea. PCR assays for tcdA and tcdB genes were conducted using 724 unduplicated C. difficile isolates. The mean prevalence of tcdA(+)tcdB(+) and tcdA(-)tcdB(+) C. difficile strains over the 6 years was 51.8 % (38.4-59.3%) and 25.8%(10-56.0%), respectively. The mean prevalence of tcdA(-)tcdB(+) C. difficile strains was less than 7% until 2002, but began to increase in 2003 (13.2%) and achieved a peak in 2004 (50.3%). In 2005, the mean prevalence of tcdA(+)tcdB(+) and tcdA(-)tcdB(+) C. difficile strains was 47.7% (30.9-60.3%) and 27.0% (17.6-54.8%), respectively. This nationwide epidemiological study showed that tcdA(-)tcdB(+) C. difficile strains have already spread extensively throughout Korea, and our results provide basic data regarding the controversies currently surrounding the toxigenicity of tcdA(-)tcdB(+) C. difficile. The use of enzyme immunoassays capable of detecting both TcdA and TcdB is strongly recommended for the diagnosis of CDAD in microbiology laboratories, in order to control the spread of the tcdA(-)tcdB(+) strains of C. difficile.
Collapse
Affiliation(s)
- Bo-Moon Shin
- Office of Infection Control, Sanggye Paik Hospital, Inje University, Seoul, Republic of Korea
- Department of Laboratory Medicine, Sanggye Paik Hospital, Inje University, Seoul, Republic of Korea
| | - Eun Young Kuak
- Department of Laboratory Medicine, Sanggye Paik Hospital, Inje University, Seoul, Republic of Korea
| | - Hyeon Mi Yoo
- Office of Infection Control, Sanggye Paik Hospital, Inje University, Seoul, Republic of Korea
| | - Eui Chong Kim
- Department of Laboratory Medicine, Seoul National University, Seoul, Republic of Korea
| | - Kyungwon Lee
- Department of Laboratory Medicine, Yonsei University, Seoul, Republic of Korea
| | - Jung-Oak Kang
- Department of Laboratory Medicine, Hanyang University, Kuri, Republic of Korea
| | - Dong Hee Whang
- Department of Laboratory Medicine, Seoul Paik Hospital, Seoul, Republic of Korea
| | - Jeong-Hwan Shin
- Department of Laboratory Medicine, Busan Paik Hospital, Busan, Republic of Korea
| |
Collapse
|
22
|
Samra Z, Luzon A, Bishara J. Evaluation of two rapid immunochromatography tests for the detection of Clostridium difficile toxins. Dig Dis Sci 2008; 53:1876-9. [PMID: 17990108 DOI: 10.1007/s10620-007-0072-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 10/14/2007] [Indexed: 01/06/2023]
Abstract
The aim of the study was to evaluate the performance of two rapid immunochromatography tests, the Tox A/B Quick Chek (TechLab) and the ImmunoCard Toxins A&B test (Meridian), in addition to the older Tox A/B ELISA, against PCR detection of the tcdB gene. Two hundred patient-unique stool specimens were tested. In comparison to the polymerase chain reaction results, the sensitivity and specificity of the two rapid tests were 94.7% and 97.2%, respectively; corresponding values for the ELISA were 93.6% and 94.3%. Findings on the rapid tests showed a 96% correlation with polymerase chain reaction assay and a 94% correlation with ELISA. Considering the importance of early and appropriate diagnosis of Clostridium difficile-associated diarrhea, rapid immunochromatography tests may be of great benefit to practitioners.
Collapse
Affiliation(s)
- Zmira Samra
- Department of Clinical Microbiology, Rabin Medical Center, Beilinson Hospital, Petah Tiqwa, Israel
| | | | | |
Collapse
|
23
|
Giesemann T, Guttenberg G, Aktories K. Human alpha-defensins inhibit Clostridium difficile toxin B. Gastroenterology 2008; 134:2049-58. [PMID: 18435932 DOI: 10.1053/j.gastro.2008.03.008] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 02/27/2008] [Accepted: 03/06/2008] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Clostridium difficile toxins A and B are major virulence factors implicated in pseudomembranous colitis and antibiotic-associated diarrhea. The toxins are glucosyltransferases, which inactivate Rho proteins involved in cellular signaling. Human alpha-defensins as part of the innate immune system inactivate various microbial pathogens as well as specific bacterial exotoxins. Here, we studied the effects of alpha-defensins human neutrophil protein (HNP)-1, HNP-3, and enteric human defensin (HD)-5 on the activity of C difficile toxins A and B. METHODS Inactivation of C difficile toxins by alpha-defensins in vivo was monitored by microscopy, determination of the transepithelial resistance of CaCo-2 cell monolayers, and analysis of the glucosylation of Rac1 in toxin-treated cells. In vitro glucosylation was used to determine K(m) and median inhibitory concentration (IC(50)) values. Formation of defensin-toxin complexes was analyzed by precipitation and turbidity studies. RESULTS Treatment of cells with human alpha-defensins caused loss of cytotoxicity of toxin B, but not of toxin A. Only alpha-defensins, but not beta-defensin-1 or cathelicidin LL-37, inhibited toxin B-catalyzed in vitro glucosylation of Rho guanosine triphosphatases in a competitive manner, increasing K(m) values for uridine 5'-diphosphate-glucose up to 10-fold. The IC(50) values for inhibition of toxin B-catalyzed glucosylation by the alpha-defensins were 0.6-1.5 micromol/L. At high concentrations, defensins (HNP-1 > or = 2 micromol/L) caused high-molecular-mass aggregates, comparable to Bacillus anthracis protective antigen and lethal factor. CONCLUSION Our data indicate that toxin B interacts with high affinity with alpha-defensins and suggest that defensins may provide a defense mechanism against some types of clostridial glucosylating cytotoxins.
Collapse
Affiliation(s)
- Torsten Giesemann
- Institut für Experimentelle and Klinische Pharmakologie und Toxikologie, Universität Freiburg, Freiburg, Germany
| | | | | |
Collapse
|
24
|
[Diarrhoea caused by Clostridium difficile in patients with postoperative subhepatic abscess]. VOJNOSANIT PREGL 2008; 65:249-54. [PMID: 18494275 DOI: 10.2298/vsp0803249s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Toxigenic strains of Clostridium difficile in the majority of cases cause disease of the intestinal tract of hospitalized patients. For a long time, Clostridium difficile was considered to produce both types of toxins (A+/B+ strain), however, the investigations conducted in the last ten years point to the existence of clinically significant isolates which produce only toxin B, i. e. toxin A negative/toxin B positive (A-/B+ strain) Clostridium difficile. CASE REPORT We presented the case of a patient admitted to the Surgery Clinic, Clinical Center Nis due to the presence of calculus in the ductus choledochus. Twenty-four hours after the surgical intervention for calculus removal, the first signs of the operative wound infection began to appear. In the course of infection treatment, different antibiotics were administered (cefuroxine, ciprofloxacin, vancomycin, imipenem). After making etiological microbiological diagnosis and application of antibiotics according to antibiogram results, the signs of the operative wound infection began to withdraw, but the patient reported the abdominal pain and liquid stools with traces of blood (up to 17 stools per day). By microbiological examination, Clostridium diffidile was cultivated and the presence of toxin B was detected in the stool samples. The patient was sent to the Clinic for Infectious Diseases, where the causal therapy of mitronidazol was administered. Liquid and electrolytes were made up by substitution therapy. After the eight-day-treatment, the patient felt much better, and diarrheas stopped on the 10th day of the therapy application. CONCLUSION Our results have shown that toxingen strains Clostridium difficile are present in our country so this bacterium sort have to be considered in differential causal diagnosis of diarrhoea syndrome. Considering that it can cause difficult form of the disease, it is an obligation to establish the presence of some toxins of Clostridium difficile in stool samples of patients and/or production of some toxins in liquid culturate of isolates to provide data for the presence of strains which produce only toxin B.
Collapse
|
25
|
Mortality of patients with antibiotic-associated diarrhoea: the impact of Clostridium difficile. J Hosp Infect 2008; 68:308-14. [DOI: 10.1016/j.jhin.2008.01.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 01/30/2008] [Indexed: 11/20/2022]
|
26
|
Drudy D, Harnedy N, Fanning S, O'Mahony R, Kyne L. Isolation and characterisation of toxin A-negative, toxin B-positive Clostridium difficile in Dublin, Ireland. Clin Microbiol Infect 2007; 13:298-304. [PMID: 17391385 DOI: 10.1111/j.1469-0691.2006.01634.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Clostridium difficile is a major cause of infectious diarrhoea in hospitalised patients. Most pathogenic C. difficile strains produce two toxins, A and B; however, clinically relevant toxin A-negative, toxin B-positive (A- B+) strains of C. difficile that cause diarrhoea and colitis in humans have been isolated worldwide. The aims of this study were to isolate and characterise A- B+ strains from two university hospitals in Dublin, Ireland. Samples positive for C. difficile were identified daily by review of ELISA results and were cultured on selective media. Following culture, toxin-specific immunoassays, IMR-90 cytotoxicity assays and PCR were used to analyse consecutive C. difficile isolates from 93 patients. Using a toxin A-specific ELISA, 52 samples produced detectable toxin. All isolates were positive using a toxin A/B ELISA. Similarly, all isolates were positive with the cytoxicity assay, although variant cytopathic effects were observed in 41 cases. PCR amplification of the toxin A and toxin B genes revealed that 41 of the previous A- B+ strains had a c. 1.7-kb deletion in the 3'-end of the tcdA gene. Restriction enzyme analysis of these amplicons revealed the loss of polymorphic restriction sites. These 41 A- B+ isolates were designated toxinotype VIII by comparison with C. difficile strain 1470. PCR ribotyping revealed that all A- B+ isolates belonged to PCR-ribotype 017. A- B+ C. difficile isolates accounted for 44% of the isolates examined in this study, and appeared to be isolated more frequently in Dublin, Ireland, than reported rates for other countries.
Collapse
Affiliation(s)
- D Drudy
- Centre for Food Safety, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Dublin, Ireland.
| | | | | | | | | |
Collapse
|
27
|
Peled N, Pitlik S, Samra Z, Kazakov A, Bloch Y, Bishara J. Predicting Clostridium difficile toxin in hospitalized patients with antibiotic-associated diarrhea. Infect Control Hosp Epidemiol 2007; 28:377-81. [PMID: 17385141 DOI: 10.1086/513723] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2006] [Accepted: 12/12/2006] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Clostridium difficile infection is implicated in 20%-30% of cases of antibiotic-associated diarrhea. Studying hospitalized patients who received antibiotic therapy and developed diarrhea, our objective was to compare the clinical characteristics of patients who developed C. difficile-associated diarrhea (CDAD) with those of patients with a negative result of a stool assay for C. difficile toxin. METHODS A prospective study was done with a cohort of 217 hospitalized patients who had received antibiotics and developed diarrhea. Patients with CDAD were defined as patients who had diarrhea and a positive result for C. difficile toxin A/B by an enzyme immunoassay of stool. The variables that yielded a significant difference on univariate analysis between patients with a positive assay result and patients with a negative assay result were entered into a logistic regression model for prediction of C. difficile toxin.Setting. A 900-bed tertiary care medical center. RESULTS Of 217 patients, 52 (24%) had a positive result of assay for C. difficile toxin A/B in their stool. The logistic regression model included impaired functional capacity, watery diarrhea, use of a proton pump inhibitor, use of a histamine receptor blocker, leukocytosis, and hypoalbuminemia. The area under the receiver operating characteristic curve for the model as a predictor of a positive result for the stool toxin assay was 0.896 (95% confidence interval, 0.661-1.000; P<.001), with 95% specificity and 68% sensitivity. CONCLUSIONS Our results may help clinicians to predict the risk of CDAD in hospitalized patients with antibiotic-associated diarrhea, to guide careful, specific empirical therapy, and to direct early attention to infection control issues.
Collapse
Affiliation(s)
- Nir Peled
- Institute of Pulmonology, Rabin Medical Center, Beilinson Hospital, Israel
| | | | | | | | | | | |
Collapse
|
28
|
Kikkawa H, Hitomi S, Watanabe M. Prevalence of toxin A-nonproducing/toxin-B-producing Clostridium difficile in the Tsukuba-Tsuchiura district, Japan. J Infect Chemother 2007; 13:35-8. [PMID: 17334727 DOI: 10.1007/s10156-006-0494-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Accepted: 11/03/2006] [Indexed: 11/30/2022]
Abstract
In Japan, many clinical laboratories may not have recognized toxin A-nonproducing/toxin B-producing (A-/B+) Clostridium difficile, because rapid diagnostic kits detecting toxin B of C. difficile have not been available in the laboratories. Therefore, we examined the prevalence of A-/B+ strains in the Tsukuba-Tsuchiura district, Japan. Fecal specimens submitted for C. difficile toxin tests in four tertiary hospitals in the district were collected for 6 months. Several C. difficile A-/B+ strains, isolated in two nosocomial outbreaks that had occurred in geographically distant areas in Japan, were also simultaneously analyzed as controls. C. difficile was isolated from 159 of 332 specimens collected. Ten (6.3%) of the 159 C. difficile strains were A-/B+ strains. Nine A-/B+ strains, isolated in one hospital, had an identical genomic pattern by polymerase chain reaction (PCR) ribotyping and macrorestriction analysis with pulsed-field gel electrophoresis (PFGE). The A-/B+ strain isolated in another hospital and some of those in the geographically distant hospitals were indistinguishable from the nine strains by PCR ribotyping but were distinguishable with PFGE analysis. We concluded that A-/B+ strains are not epidemic in this district and that PFGE analysis may be preferable to PCR ribotyping for the genotyping of C. difficile A-/B+ strains. The reason why most of the A-/B+ strains were detected in the one hospital was unclear.
Collapse
Affiliation(s)
- Hiromi Kikkawa
- Department of Clinical Laboratory, Tsuchiura Kyodo General Hospital, Tsuchiura, Japan
| | | | | |
Collapse
|
29
|
Drudy D, Fanning S, Kyne L. Toxin A-negative, toxin B-positive Clostridium difficile. Int J Infect Dis 2007; 11:5-10. [PMID: 16857405 DOI: 10.1016/j.ijid.2006.04.003] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 03/31/2006] [Accepted: 04/17/2006] [Indexed: 11/26/2022] Open
Abstract
Clostridium difficile is a major cause of infectious diarrhea in hospitalized patients. Many pathogenic strains of Clostridium difficile produce two toxins TcdA and TcdB, both of which are pro-inflammatory and enterotoxic in human intestine. Clinically relevant toxin A-negative, toxin B-positive (A(-)B(+)) strains of Clostridium difficile that cause diarrhea and colitis in humans have been isolated with increasing frequency worldwide. This perspective describes these important toxin variant strains and highlights the need to use Clostridium difficile diagnostic methods that can detect both TcdA and TcdB.
Collapse
Affiliation(s)
- Denise Drudy
- Centre for Food Safety, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
| | | | | |
Collapse
|
30
|
Yahav J, Samra Z, Blau H, Dinari G, Chodick G, Shmuely H. Helicobacter pylori and Clostridium difficile in cystic fibrosis patients. Dig Dis Sci 2006; 51:2274-9. [PMID: 17078007 DOI: 10.1007/s10620-006-9271-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 02/15/2006] [Indexed: 12/09/2022]
Abstract
We describe the prevalence of H. pylori and toxigenic Clostridium difficile (CD) infection and its relationship with gastrointestinal symptoms and pancreatic sufficiency (PS) or insufficiency (PI) in cystic fibrosis (CF) patients. Stool specimens from 30 consecutive patients with CF, aged 1-44, and from 30 healthy similarly aged subjects were tested for the H. pylori antigen by specific monoclonal antibodies and for CD toxins by Tox A/B assay and Tox A assay. CF patients were assessed clinically and tested for specific H. pylori serum antibodies and for mutations. In CF patients, the prevalence of H. pylori antigen was 16.6% (5/30), compared to 30% (9/30) in controls. Of the 26 CF patients with PI, only 2 (7.6%) were infected by H. pylori, compared with 3 of the 4 (75%) patients with PS (P=0.001). H. pylori infection was diagnosed in 3 of 5 (60%) CF patients carrying mild mutations, compared to 1 of 25 (4%) CF patients carrying severe mutations (P=0.01). Fourteen of 30 (46.6%) stool specimens from CF patients tested positive in the ToxA/B assay, and 3 of 14 tested positive for ToxA. No significant differences in antibiotic use, severity of lung disease, PI, chronic abdominal pain, or genotype were found between the two groups. None of the controls was positive for CD toxins. Prevalence of H. pylori infection in CF patients was lower than in similarly aged non-CF controls. CF patients with PI or a history of distal intestinal obstruction syndrome and those carrying mutations associated with a severe phenotype were protected against H. pylori infection. Almost half of the CF patients were asymptomatic carriers of CD producing mostly toxin B. More studies are needed to confirm our results in a larger group of CF patients.
Collapse
Affiliation(s)
- Jacob Yahav
- Helicobacter Research Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva, 49100, Israel.
| | | | | | | | | | | |
Collapse
|
31
|
Bishara J, Bloch Y, Garty M, Behor J, Samra Z. Antimicrobial resistance of Clostridium difficile isolates in a tertiary medical center, Israel. Diagn Microbiol Infect Dis 2006; 54:141-4. [PMID: 16406180 DOI: 10.1016/j.diagmicrobio.2005.09.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Revised: 09/23/2005] [Accepted: 09/26/2005] [Indexed: 11/27/2022]
Abstract
The antimicrobial susceptibilities of 49 Clostridium difficile isolates obtained from patients with C. difficile-associated diarrhea to metronidazole, vancomycin, rifampicin, fusidic acid, doxycycline, and linezolid were determined by the disc diffusion and Etest (Biodisk, Solna, Sweden). Random amplification of polymorphic DNA-PCR amplification assay was performed for studying clonality of isolates. Resistance to metronidazole was found in 2% (1/49 isolates; MIC > or = 256 microg/mL) of isolates and resistance to linezolid in 2% (1/49 isolates; MIC = 24 microg/mL). One isolate showed combined resistance to fusidic acid (by disc diffusion test) and rifampicin (MIC > or = 32 microg/mL). All isolates were sensitive to doxycycline and vancomycin. Molecular typing revealed an absence of clonality among the resistant isolates, whereas the sensitive isolates were monoclonal. Resistance of C. difficile to metronidazole and other antimicrobials including linezolid exists in our institution. This finding should promote exploration of this problem in Israel and clarify the impact of resistance on outcome.
Collapse
Affiliation(s)
- Jihad Bishara
- Infectious Diseases Unit, Rabin Medical Center, Beilinson Campus, Petah Tiqva 49100, Israel.
| | | | | | | | | |
Collapse
|
32
|
Abstract
As the leading cause of hospital-acquired diarrhea, Clostridium difficile colonizes the large bowel of patients undergoing antibiotic therapy and produces two toxins, which cause notable disease pathologies. These two toxins, TcdA and TcdB, are encoded on a pathogenicity locus along with negative and positive regulators of their expression. Following expression and release from the bacterium, TcdA and TcdB translocate to the cytosol of target cells and inactivate small GTP-binding proteins, which include Rho, Rac, and Cdc42. Inactivation of these substrates occurs through monoglucosylation of a single reactive threonine, which lies within the effector-binding loop and coordinates a divalent cation critical to binding GTP. By glucosylating small GTPases, TcdA and TcdB cause actin condensation and cell rounding, which is followed by death of the cell. TcdA elicits effects primarily within the intestinal epithelium, while TcdB has a broader cell tropism. Important advances in the study of these toxins have been made in the past 15 years, and these are detailed in this review. The domains, subdomains, and residues of these toxins important for receptor binding and enzymatic activity have been elegantly studied and are highlighted herein. Furthermore, there have been major advances in defining the role of these toxins in modulating the inflammatory events involving the disruption of cell junctions, neuronal activation, cytokine production, and infiltration by polymorphonuclear cells. Collectively, the present review provides a comprehensive update on TcdA and TcdB's mechanism of action as well as the role of these toxins in disease.
Collapse
Affiliation(s)
- Daniel E Voth
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | | |
Collapse
|
33
|
Delmée M, Van Broeck J, Simon A, Janssens M, Avesani V. Laboratory diagnosis of Clostridium difficile-associated diarrhoea: a plea for culture. J Med Microbiol 2005; 54:187-191. [PMID: 15673515 DOI: 10.1099/jmm.0.45844-0] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A routine protocol for diagnosing Clostridium difficile-associated diarrhoea (CDAD) based on both faecal-cytotoxin detection and toxigenic culture was adopted by the microbiology laboratory of the St Luc-UCL University Hospital in Brussels in 1997. A toxigenic culture is a faecal culture followed, in the case of positivity, by a direct immunoassay on colonies to detect toxin A production. The results obtained over the past 7 years in the hospital are reviewed here. A total of 10,552 diarrhoeal stools from 7042 patients were analysed, of which 9494 were negative for all tests. A total of 1058 samples (10 %) from 794 patients were culture-positive, of which 460 (4.4 %) were positive for a faecal cytotoxin. The remaining 598 cultures were tested for toxin A on colonies; 355 of them were positive, which is 3.4 % of the total, and the remaining 243 (2.3 %) were negative. The positivity of the faecal-cytotoxin assay was statistically linked to the number of colonies observed on the culture plate. In conclusion, over a 7 year period, toxigenic culture allowed the diagnosis of 355 cases of CDAD that would have been missed by a protocol using a faecal-cytotoxin assay alone. In terms of both patient care, prevention of environmental contamination and prevention of risk of a hospital outbreak, it is proposed that these results justify the recommendation to perform both faecal-toxin assay and culture in routine medical practice.
Collapse
Affiliation(s)
- Michel Delmée
- Université Catholique de Louvain, Microbiology Unit, Avenue Hippocrate, 54.90, B-1200 Brussels, Belgium
| | - Johan Van Broeck
- Université Catholique de Louvain, Microbiology Unit, Avenue Hippocrate, 54.90, B-1200 Brussels, Belgium
| | - Anne Simon
- Université Catholique de Louvain, Microbiology Unit, Avenue Hippocrate, 54.90, B-1200 Brussels, Belgium
| | - Michèle Janssens
- Université Catholique de Louvain, Microbiology Unit, Avenue Hippocrate, 54.90, B-1200 Brussels, Belgium
| | - Véronique Avesani
- Université Catholique de Louvain, Microbiology Unit, Avenue Hippocrate, 54.90, B-1200 Brussels, Belgium
| |
Collapse
|
34
|
Lemee L, Dhalluin A, Testelin S, Mattrat MA, Maillard K, Lemeland JF, Pons JL. Multiplex PCR targeting tpi (triose phosphate isomerase), tcdA (Toxin A), and tcdB (Toxin B) genes for toxigenic culture of Clostridium difficile. J Clin Microbiol 2005; 42:5710-4. [PMID: 15583303 PMCID: PMC535266 DOI: 10.1128/jcm.42.12.5710-5714.2004] [Citation(s) in RCA: 264] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A multiplex PCR toxigenic culture approach was designed for simultaneous identification and toxigenic type characterization of Clostridium difficile isolates. Three pairs of primers were designed for the amplification of (i) a species-specific internal fragment of the tpi (triose phosphate isomerase) gene, (ii) an internal fragment of the tcdB (toxin B) gene, and (iii) an internal fragment of the tcdA (toxin A) gene allowing distinction between toxin A-positive, toxin B-positive (A+B+) strains and toxin A-negative, toxin B-positive (A-B+) variant strains. The reliability of the multiplex PCR was established by using a panel of 72 C. difficile strains including A+B+, A-B-, and A-B+ toxigenic types and 11 other Clostridium species type strains. The multiplex PCR assay was then included in a toxigenic culture approach for the detection, identification, and toxigenic type characterization of C. difficile in 1,343 consecutive human and animal stool samples. Overall, 111 (15.4%) of 721 human samples were positive for C. difficile; 67 (60.4%) of these samples contained A+B+ toxigenic isolates, and none of them contained A-B+ variant strains. Fifty (8%) of 622 animal samples contained C. difficile strains, which were toxigenic in 27 (54%) cases, including 1 A-B+ variant isolate. Eighty of the 721 human stool samples (37 positive and 43 negative for C. difficile culture) were comparatively tested by Premier Toxins A&B (Meridian Bioscience) and Triage C. difficile Panel (Biosite) immunoassays, the results of which were found concordant with toxigenic culture for 82.5 and 92.5% of the samples, respectively. The multiplex PCR toxigenic culture scheme described here allows combined diagnosis and toxigenic type characterization for human and animal C. difficile intestinal infections.
Collapse
Affiliation(s)
- Ludovic Lemee
- Groupe de Recherche sur les Antimicrobiens et les Microorganismes, Université de Rouen, UFR Médecine-Pharmacie, and Service de Bactériologie, Centre Hospitalier Universitaire, France
| | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
Blake JE, Mitsikosta F, Metcalfe MA. Immunological detection and cytotoxic properties of toxins from toxin A-positive, toxin B-positive Clostridium difficile variants. J Med Microbiol 2004; 53:197-205. [PMID: 14970244 DOI: 10.1099/jmm.0.05404-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Clostridium difficile is a major nosocomial pathogen and a causative agent of antibiotic-associated diarrhoea and pseudomembranous colitis. PCR analysis of the toxin A and B genes of this bacterium has revealed 20 variant types (toxinotypes I-XX), many of which can cause human disease. Strains comprising the 15 toxin A-positive, toxin B-positive toxinotypes are not usually differentiated from non-variant strains by routine laboratories that do not utilize PCR tests. Consequently, the toxins from these variant strains have not been investigated thoroughly. The present studies revealed that toxin A-positive (A+B+) strains representing 12 variant toxinotypes all express considerably lower levels of toxin A and are less cytotoxic in vitro than non-variant strain VPI 10463. Truncated forms of toxin A were detected by immunoblotting in toxinotype VI and VII strains and these toxins were differentiated from each other and from toxin A of the non-variant strain. A further novel finding was the ability of toxin A-positive (A+B+) strains of toxinotypes IX, XIV and XV to exhibit an alternative Clostridium sordellii-like cytopathic effect on Vero cells, characterized by marked cell clumping. A rapid and simple method for toxin A removal from culture filtrates was developed. This enabled confirmation that the abnormal cytotoxicity observed for these strains is due to an altered toxin B, as has been found in toxin A-negative (A-B+) strains. These findings indicate the potential for differentiation of certain toxin A-positive (A+B+) toxinotypes without the need for PCR techniques.
Collapse
Affiliation(s)
- J E Blake
- Immunology Research and Development Section, Oxoid Ltd, Wade Road, Basingstoke RG24 8PW, UK
| | - F Mitsikosta
- Immunology Research and Development Section, Oxoid Ltd, Wade Road, Basingstoke RG24 8PW, UK
| | - M A Metcalfe
- Immunology Research and Development Section, Oxoid Ltd, Wade Road, Basingstoke RG24 8PW, UK
| |
Collapse
|
37
|
|