Characterization of
            <i>Clostridium difficile</i>
            Strains Isolated from Patients in Ontario, Canada, from 2004 to 2006

Martin, Hayley; Willey, Barbara M.; Low, Donald E.; Staempfli, H. R.; McGeer, Allison; Mulvey, Michael R.; Weese, J. Scott

doi:10.1128/jcm.02437-07

Cited by 82 publications

(74 citation statements)

References 44 publications

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“…Thus, like REA, some NAP strain designations appear to encompass more isolate types than are recognized by the other typing methods. Martin and colleagues have made this same observation (32). For a laboratory wishing to initiate typing of C. difficile isolates, the Simpson's index of diversity scores and Wallace coefficients from our data set indicate that PCR-ribotyping should be the primary method of strain differentiation.…”

Section: Discussionmentioning

confidence: 90%

“…Our data indicate that group DH strains could be ribotypes 002, 046, and 053 in addition to 106, while group J strains could be ribotype 046 in addition to ribotype 001, potentially altering the interpretation of the data. Martin and colleagues typed 1,080 C. difficile isolates from Ontario, Canada, by multiple methods, including PCR-ribotyping, but performed PFGE and toxinotyping only on selected isolates (32). While the study did not provide adequate information about the congruence of the typing methods, the authors did note that NAP1 isolates could be assigned one of three ribotypes and that NAP2 isolates could be divided into four distinct ribotypes.…”

Section: Discussionmentioning

confidence: 98%

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Comparison of Strain Typing Results for Clostridium difficile Isolates from North America

Tenover¹,

Åkerlund

Gerding

et al. 2011

J Clin Microbiol

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Accurate strain typing is critical for understanding the changing epidemiology of Clostridium difficile infections. We typed 350 isolates of toxigenic C. difficile from 2008 to 2009 from seven laboratories in the United States and Canada. Typing was performed by PCR-ribotyping, pulsed-field gel electrophoresis (PFGE), and restriction endonuclease analysis (REA) of whole-cell DNA. The Cepheid Xpert C. difficile test for presumptive identification of 027/NAP1/BI isolates was also tested directly on original stool samples. Of 350 isolates, 244 (70%) were known PCR ribotypes, 224 (68%) were 1 of 8 common REA groups, and 187 (54%) were known PFGE types. Eighty-four isolates typed as 027, NAP1, and BI, and 83 of these were identified as presumptive 027/NAP1/BI by Xpert C. difficile. Eight additional isolates were called presumptive 027/NAP1/BI by Xpert C. difficile, of which three were ribotype 027. Five PCR ribotypes contained multiple REA groups, and three North American pulsed-field (NAP) profiles contained both multiple REA groups and PCR ribotypes. There was modest concordance of results among the three methods for C. difficile strains, including the J strain (ribotype 001 and PFGE NAP2), the toxin A-negative 017 strain (PFGE NAP9 and REA type CF), the 078 animal strain (PFGE NAP7 and REA type BK), and type 106 (PFGE NAP11 and REA type DH). PCR-ribotyping, REA, and PFGE provide different but overlapping patterns of strain clustering. Unlike the other methods, the Xpert C. difficile 027/NAP1/BI assay gave results directly from stool specimens, required only 45 min to complete, but was limited to detection of a single strain type.

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Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 98%

Comparison of Strain Typing Results for Clostridium difficile Isolates from North America

Tenover¹,

Åkerlund

Gerding

et al. 2011

J Clin Microbiol

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“…Additionally, 12 C. difficile isolates with vancomycin MICs of 4 mg/liter, comprising PCR ribotypes 106 (n ϭ 6), 001 (n ϭ 5), and 027 (n ϭ 1), were observed (69), compared with only a single isolate in our prior study (9). In a similarly large susceptibility study of 1,080 stool samples from diagnostic laboratories in Ontario, Canada, Martin et al reported 19 (1.8%) C. difficile isolates with metronidazole MICs of Ͼ8 mg/liter and 4 isolates with vancomycin MICs of 4 mg/liter (128). However, the C. difficile isolates (including PCR ribotypes 027 and 078) were only transiently resistant by Etest, with resistance apparently being lost upon repeated subculturing, which reflects data from previously reported in vitro studies (151).…”

Section: Susceptibility Of C Difficile To Metronidazole and Vancomycinmentioning

confidence: 99%

The Changing Epidemiology of Clostridium difficile Infections

et al. 2010

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SUMMARY The epidemiology of Clostridium difficile infection (CDI) has changed dramatically during this millennium. Infection rates have increased markedly in most countries with detailed surveillance data. There have been clear changes in the clinical presentation, response to treatment, and outcome of CDI. These changes have been driven to a major degree by the emergence and epidemic spread of a novel strain, known as PCR ribotype 027 (sometimes referred to as BI/NAP1/027). We review the evidence for the changing epidemiology, clinical virulence and outcome of treatment of CDI, and the similarities and differences between data from various countries and continents. Community-acquired CDI has also emerged, although the evidence for this as a distinct new entity is less clear. There are new data on the etiology of and potential risk factors for CDI; controversial issues include specific antimicrobial agents, gastric acid suppressants, potential animal and food sources of C. difficile, and the effect of the use of alcohol-based hand hygiene agents.

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“…Clostridium difficile infection (CDI) has increased in frequency and severity in North America and Europe over the last 5 years, largely due to the emergence of the epidemic PCR ribotype 027 strain (10,11). The diagnosis of CDI is usually based on a clinical history of recent antimicrobial usage and diarrhea in combination with laboratory tests (9).…”

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confidence: 99%

Comparison of a Commercial Multiplex Real-Time PCR to the Cell Cytotoxicity Neutralization Assay for Diagnosis of Clostridium difficile Infections

et al. 2009

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A commercial multiplex real-time PCR assay (Cepheid Xpert C. difficile assay) for the diagnosis of Clostridium difficile infection was evaluated. The sensitivity and specificity of the Cepheid assay were 97.1% and 93.0% for fresh stools, using the cell cytotoxicity neutralization assay as the reference. Using PCR ribotyping as the reference for ribotype 027 strains, the corresponding figures were 100% and 98.1%, respectively.Clostridium difficile infection (CDI) has increased in frequency and severity in North America and Europe over the last 5 years, largely due to the emergence of the epidemic PCR ribotype 027 strain (10, 11). The diagnosis of CDI is usually based on a clinical history of recent antimicrobial usage and diarrhea in combination with laboratory tests (9). Therefore, rapid and accurate microbiological diagnosis is urgently needed. The Cepheid Xpert C. difficile assay (Sunnyvale, CA) is a real-time multiplex PCR assay performed on the Cepheid GeneXpert Dx system. Proprietary primers specific for the toxin B gene (tcdB), binary toxin genes (cdtA and cdtB), and tcdC gene single-base deletion at nucleotide 117 were designed to detect toxigenic C. difficile and the presumptive PCR ribotype 027 strain. The purpose of this study was to evaluate the Cepheid Xpert C. difficile multiplex real-time PCR assay for the detection of toxigenic C. difficile strains and the presumptive ribotype 027.There were four serial investigations in the present study. In investigation 1, 205 frozen C. difficile strains collected during 2007 and 2008 were analyzed. In investigation 2, 195 frozen stool specimens belonging to different categories were selected based on direct cell cytotoxicity neutralization assay (CCNA) and toxigenic anaerobic culture results. Because PCR ribotype 027 is uncommon in Sweden, 40 frozen stool specimens collected in the United States were also analyzed. In investigation 3, 30 pairs of fresh-frozen stool specimens were analyzed. The fresh stool was analyzed within 24 h of collection, and then the leftover was stored at Ϫ20°C for 3 days and retested. In investigation 4, 220 consecutive fresh, unformed stool specimens (Bristol Stool Chart grade 5 to 7) from patients older than 2 years were analyzed within 24 h of collection. Eligible participants were those symptomatic patients who had a stool sample submitted to the Karolinska University Hospital for routine C. difficile testing.Unrepeated strains and stools were determined for C. difficile test by CCNA with a commercial C. difficile toxin/antitoxin kit (TechLab, Blacksburg, VA). For the stool specimens, anaerobic cultures on selective taurocholate cycloserine-cefoxitin-fructose agar plates were also performed (13). All isolates were typed by PCR ribotyping (19).Concurrently, the Cepheid Xpert C. difficile assay was performed according to protocols provided by the manufacturer. Each kit contained single-use disposable cartridges with integrated reaction chambers and reagents. A sterile Copan swab was dipped into the stool specimen or used to pick one...

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Characterization of Clostridium difficile Strains Isolated from Patients in Ontario, Canada, from 2004 to 2006

Abstract: Clostridium difficile is the bacterium most commonly surmised to cause antimicrobial-and hospital-associated diarrhea in developed countries worldwide, and such infections are thought to be increasing in frequency and severity. A laboratory-based study was carried out to characterize C.

Cited by 82 publications

References 44 publications

Comparison of Strain Typing Results for Clostridium difficile Isolates from North America

Comparison of Strain Typing Results for Clostridium difficile Isolates from North America

The Changing Epidemiology of Clostridium difficile Infections

Comparison of a Commercial Multiplex Real-Time PCR to the Cell Cytotoxicity Neutralization Assay for Diagnosis of Clostridium difficile Infections

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