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-associated diarrhea. This article presents data related to C. perfringens.
Material/methods: Stool samples taken from 158 patients with suspected antibiotic-associated diarrhea were specifically cultured for Clostridium difficile, Bacteroides fragilis and Clostridium perfringens. In order to associate the presence of virulence factors in the bacterial isolates thus collected with disease features, all strains were genetically and phenotypically analyzed for toxin production. All isolated C. perfringens strains were cultured in Ellner sporulation-promoting medium.
Results: In 21 of the 158 patients (13%) C. perfringens could be cultivated from the fecal specimen. None of the strains produced enterotoxin, and consequently the cpe gene was not detected by PCR in any of these strains. C. perfringens and C. difficile were cultivated from the same stool samples in 4 cases. Interestingly, in one case toxin A-negative/toxin B positive C. 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. perfringens strains, 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 that C. perfringens is not a major primary cause of antibiotic-associated diarrhea.