Open AccessImpact of Strain Type on Detection of Toxigenic Clostridium difficile: Comparison of Molecular Diagnostic and Enzyme Immunoassay Approaches
Author(s) -
Fred C. Tenover,
Susan Novak-Weekley,
Christopher W. Woods,
Lance R. Peterson,
Thomas E. Davis,
Paul C. Schreckenberger,
Ferric C. Fang,
André Dascal,
Dale N. Gerding,
Jim Nomura,
Richard V. Goering,
Thomas Åkerlund,
Alice S. Weissfeld,
Ellen Jo Baron,
Edith Y. Wong,
Elizabeth M. Marlowe,
Joseph Whitmore,
David H. Persing
Publication year - 2010
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.00427-10
Subject(s) - clostridium difficile , immunoassay , glutamate dehydrogenase , microbiology and biotechnology , clostridioides , clostridiaceae , medicine , ribotyping , virology , biology , polymerase chain reaction , antibiotics , immunology , toxin , antibody , glutamate receptor , receptor , biochemistry , gene
A multicenter clinical trial assessed the performance of the Cepheid XpertC. difficile assay on stool specimens collected from patients suspected of havingClostridium difficile infection (CDI). A total of 2,296 unformed stool specimens, collected from seven study sites, were tested by XpertC. difficile enrichment culture followed by cell culture cytotoxicity testing of the isolates (i.e., toxigenic culture with enrichment) and the study sites' standardC. difficile test methods. The methods included enzyme immunoassay (EIA), direct cytotoxin testing, and two- and three-step algorithms using glutamate dehydrogenase (GDH) screening followed by either EIA or EIA and an in-house PCR assay. AllC. difficile strains were typed by PCR-ribotyping. Compared to results for toxigenic culture with enrichment, the sensitivity, specificity, and positive and negative predictive values of the Xpert assay were 93.5, 94.0, 73.0, and 98.8%, respectively. The overall sensitivity of the EIAs compared to that of enrichment culture was 60.0%, and the sensitivity of combined GDH algorithms was 72.9%; both were significantly lower than that of XpertC. difficile (P < 0.001 andP = 0.03, respectively). The sensitivity of the EIA was significantly lower than that of the XpertC. difficile assay for detection of ribotypes 002, 027, and 106 (P < 0.0001,P < 0.0001, andP = 0.004, respectively, Fisher's exact test), and the sensitivity of GDH algorithms for ribotypes other than 027 was lower than that for XpertC. difficile (P < 0.001). The XpertC. difficile assay is a simple, rapid, and accurate method for detection of toxigenicC. difficile in unformed stool specimens and is minimally affected by strain type compared to EIA and GDH-based methods.