Abstract
Clostridium difficile infection (CDI) is one of the major causes of nosocomial diarrhea, particularly in patients with microbial substitution on antimicrobial therapy. For proper treatment of the diarrhea and prevention of the spread of C. difficile, high-sensitivity detection of the organism is preferred. To diagnose CDI, a rapid immunoassay kit (Alere Medical Co.) to detect both glutamate dehydrogenase (GDH) and CD toxin A or B in stool specimens has been employed in our hospital. Since false-negative cases existed in tests using a stool-direct assay, we applied a culture test to improve the detection of the CD toxins. GDH-positive and CD-toxin-negative stool specimens were anaerobically cultured, and the productions of the CD toxins by the strains grown were tested using the kit. The CD toxins were positive in 34 (7%) out of 457 cases of suspected CDI from October 2013 to March 2014 by the stool-direct assay alone, and the number of toxin-positive cases increased to 58 (13%) with the additional culture test. For the precise diagnosis of CDI, we recommend that the direct toxin detection in stools should be combined with stool culture in cases in which the stool specimens are positive for GDH.
