Usefulness of genetic test for Clostridium difficile toxin gene using BD MAX CDIFF in combination with immunochromatography, C. DIFF QUIK CHEK COMPLETE

Abstract

Clostridium difficile is a pathogen causing antibiotics-associated colitis. Appropriate infection control for patients with C. difficile is required to prevent nosocomial infection. Immunochromatography with C. DIFF QUIK CHEK COMPLETE (Aerial Medical) (QUIK CHEK), which detects C. difficile-specific glutamate dehydrogenase (GDH) and toxins (CD toxins), is used as the screening test for C. difficile infection. It has been reported that the sensitivity of QUIK CHEK in detecting CD toxins in stool is relatively low. Therefore, when samples test positive for GDH but negative for CD toxins using QUIK CHEK, stool samples are processed for bacterial culture. If C. difficile colonies are obtained, they are tested for CD toxins by the same assay. However, it takes about 2 days for colonies to form, thus delaying the diagnosis of C. difficile infection. To solve this problem, we conducted real-time PCR analysis to detect the CD toxin B gene using BD MAX CDIFF (Becton, Dickinson and Company). The sensitivity of BD MAX CDIFF in detecting the CD toxin B gene was shown to be higher than or equal to that of QUIK CHEK to detect GDH of C. difficile. When we tested 38 clinical samples, 24 samples tested positive for GDH but negative for CD toxin B, and the results of 22 of them tested using BD MAX CDIFF almost agreed with those obtained using QUIK CHEK. Taken together, BD MAX CDIFF is considered as a quick and useful tool for the confirmation of the presence of CD toxins in samples.