Evaluation of the C. DIFFICILE TOXIN A/B IITM, C. DIFF CHEK-60TM, and PREMIER TOXIN A&BTM with the cytotoxin assay for the detection of Clostridium difficile GDH antigen and toxins A and B in feces

Abstract

Background: C difficile causes about 25% of the cases of antibiotic-associated diarrhea and most cases of pseudomembranous colitis. Rapid assays have been developed to detect the toxins A and B and the enzyme glutamate dehydrogenase which is produced in high levels by all strains of the organism. Because this enzyme is present in both toxigenic and nontoxigenic strains of the organism, the assay can not confirm the presence of toxigenic organisms in a sample. However, the absence of this enzyme in a sample should be a good marker for the absence of the organism, making it a suitable screening assay to identify negative specimens. Methods: We compared two commercial EIA assays for detecting toxins A and B, and an EIA assay for detecting the GDH enzyme with our in-house cytotoxin assay as the ‘‘gold standard.’’ All commercial assays were performed according to the manufacturer’s instructions. span.jajahWrapper {font-size:1em; color:#B11196; text-decoration:underline;} a.jajahLink { color:#000000; text-decoration:none;} span.jajahInLink:hover {background-color:#B11196;} Results: Fecal samples (N = 236) submitted for C. difficile cytotoxin assay were included in this study. The C. DIFF CHEK-60TM, detected all 10 of the cytotoxin positive specimens and was positive for 28 specimens where cytotoxin was not detected by any of the toxin assays. The C. DIFFICILE TOXIN A/B IITM detected all 10 of the cytotoxin positive specimens and gave no false-positive results. The PREMIER TOXIN AB color:#B11196; text-decoration:underline;} a.jajahLink { color:#000000; text-decoration:none;} span.jajahInLink:hover {background-color:#B11196;} Conclusion: The GDH assay detected 100% of the cytotoxin positive specimens making it a useful assay for screening specimens for detecting C difficile. This would allow for the rapid reporting of the negative specimens that made up 84% of the specimens examined in this study. GDH positive assays should then be tested with an assay specific for the toxins. span.jajahWrapper {fontsize:1em; color:#B11196; text-decoration:underline;} a.jajahLink { color:#000000; text-decoration:none;} span.jajahInLink:hover {background-color:#B11196;}.