Article

Is a Two-Step Glutamate Dehyrogenase Antigen-Cytotoxicity Neutralization Assay Algorithm Superior to the Premier Toxin A and B Enzyme Immunoassay for Laboratory Detection of Clostridium difficile?

Clinical Microbiology-Immunology Laboratories, UNC Hospitals, CB 7600, Chapel Hill, NC 27514, USA.
Journal of clinical microbiology (Impact Factor: 3.99). 05/2008; 46(4):1523-5. DOI: 10.1128/JCM.02100-07
Source: PubMed

ABSTRACT

A two-step algorithm for the detection of Clostridium difficile by the use of C. Diff Quik Chek (TechLab, Blacksburg, VA) and a tissue culture cytotoxicity neutralization assay was found
to be more sensitive than the widely used solid-phase enzyme immunoassay (EIA), the Premier toxin A and B EIA (Meridian Bioscience,
Cincinnati, OH), and a newly developed, rapid single-test EIA for C. difficile toxins A and B (Tox A/B Quik Chek; TechLab).

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Available from: ncbi.nlm.nih.gov
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    • "A variety of algorithms employing EIAs, CCNAs, and/ or molecular methods to detect toxigenic C. difficile have been implemented in some laboratories (Figure 1). Many of these algorithms employ a first step that relies on the rapid, sensitive, inexpensive GDH assay followed by a second step that ensures specificity (a second EIA, CCNA, or molecular method) [38, 51, 54]. The performance of such approaches has been extensively evaluated and, depending on the specific assays employed, achieves sensitivities of 75% –100%, compared with molecular methods or toxigenic culture, and has excellent specificity [35, 38, 40, 42, 44, 51, 53,555657. "
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    ABSTRACT: Physicians should understand the performance characteristics of evolving laboratory tests used to diagnose Clostridium difficile infection if they are to correctly integrate test results with clinical information and formulate an appropriate therapeutic intervention for patients with antibiotic-associated diarrhea.
    Preview · Article · Jun 2011 · Clinical Infectious Diseases
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    • "Our data support the findings of Eastwood et al. suggesting an important role of molecular detection of CDI in the future. A number of studies have used two-or three step approaches for the diagnosis of CDI (Fenner et al., 2008; Gilligan, 2008; Kvach et al., 2009; Sharp et al., 2009; Shin et al., 2009). Our screening PCR would provide an excellent first step with a very high NPV. "
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    ABSTRACT: We have developed and validated a rapid molecular screening protocol for toxigenic Clostridium difficile, that also enables the identification of the hypervirulent epidemic 027/NAP1 strain. We describe a multiplex real-time PCR assay, which detects the presence of the tcdA and tcdB genes directly in stool samples. In case of positive PCR results, a separate multiplex real-time PCR typing assay was performed targeting the tcdC gene frame shift mutation at position 117. We prospectively compared the results of the screening PCR with those of a cytotoxicity assay (CTA), and a rapid immuno-enzyme assay for 161 stool samples with a specific request for diagnosis of C. difficile infection (CDI). A total of 16 stool samples were positive by CTA. The screening PCR assay confirmed all 16 samples, and gave a PCR positive signal in eight additional samples. The typing PCR assay detected the tcdC Δ117 mutation in 2/24 samples suggesting the presence of the epidemic strain in these samples. This was confirmed by PCR ribotyping and sequencing of the tcdC gene. Using CTA as the "gold standard", the sensitivity, specificity, positive predictive value, and negative predictive value, for the screening PCR were 100%, 94.4%, 66.7%, and 100%, respectively. In conclusion, PCR may serve as a rapid negative screening assay for patients suspected of having CDI, although the low PPV hamper the use of PCR as a standalone test. However, PCR results may provide valuable information for patient management and minimising the spread of the epidemic 027/NAP1 strain.
    Full-text · Article · Oct 2010 · Journal of microbiological methods
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    ABSTRACT: Not Available
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