BACKGROUND: The aim of our research was to investigate the role of enterotoxin-producing anaerobic bacteria other than Clostridium difficile in the etiology of antibiotic-associateddiarrhea. This article presents data related to C. perfringens. MATERIAL/METHODS: Stool samples takenfrom 158 patients with suspected antibiotic-associated diarrhea were specifically cultured for Clostridiumdifficile, Bacteroides fragilis and Clostridium perfringens. In order to associate the presence of virulencefactors in the bacterial isolates thus collected with disease features, all strains were geneticallyand phenotypically analyzed for toxin production. All isolated C. perfringens strains were cultured inEllner sporulation-promoting medium. RESULTS: In 21 of the 158 patients (13%) C. perfringens could becultivated from the fecal specimen. None of the strains produced enterotoxin, and consequently the cpegene was not detected by PCR in any of these strains. C. perfringens and C. difficile were cultivatedfrom the same stool samples in 4 cases. Interestingly, in one case toxin A-negative/toxin B positiveC. difficile and non-enterotoxigenic C. perfringens were co-cultured. After application of a heat shock(100 degrees C at 30 min.) only two C. perfringens strains producing thermoresistant spores were detected.Pulsed field gel electrophoresis (PFGE) demonstrated genetic heterogenicity among the C. perfringensstrains, suggesting that these bacteria were already presented upon hospital admission. CONCLUSIONS:It seems unlikely that nosocomial transfer has taken place. The relatively low incidence suggests thatC. perfringens is not a major primary cause of antibiotic-associated diarrhea.

Keywords: Anti-Bacterial Agents, Bacteroides fragilis, Clostridium perfringens, diarrhea, Enterotoxins, Feces, Phylogeny, Poland, Research Support, Non-U.S. Gov