Presumptive identification of Clostridium difficile strain 027/NAP1/BI on Cepheid Xpert: interpret with caution.
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ABSTRACT:
SUBMITTER: Kok J
PROVIDER: S-EPMC3187338 | biostudies-literature | 2011 Oct
REPOSITORIES: biostudies-literature
Publications
Presumptive identification of Clostridium difficile strain 027/NAP1/BI on Cepheid Xpert: interpret with caution.
Kok Jen J Wang Qinning Q Thomas Lee C LC Gilbert Gwendolyn L GL
Journal of clinical microbiology 20110817 10
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Project description:Clostridioides difficile produces toxins that damage the colonic epithelium, causing colitis. Variation in disease severity is poorly understood and has been attributed to host factors and virulence differences between C. difficile strains. We test 23 epidemic ST1 C. difficile clinical isolates for their virulence in mice. All isolates encode a complete Tcd pathogenicity locus and achieve similar colonization densities. However, disease severity varies from lethal to avirulent infections. Genomic analysis of avirulent isolates reveals a 69-bp deletion in the cdtR gene, which encodes a response regulator for binary toxin expression. Deleting the 69-bp sequence in virulent R20291 strain renders it avirulent in mice with reduced toxin gene transcription. Our study demonstrates that a natural deletion within cdtR attenuates virulence in the epidemic ST1 C. difficile isolates without reducing colonization and persistence. Distinguishing strains on the basis of cdtR may enhance the specificity of diagnostic tests for C. difficile colitis.
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