Occurrence of toxin-producingClostridium difficile in antibiotic-associated diarrhea in Sweden

Abstract

From 1324 patients with antibiotic-associated diarrhea (AAD) 1643 stool samples were analyzed by a cell test forClostridium difficile toxin in stool filtrates and cultivation for occurrence ofC. difficile strains. In patients with no detectable toxin in their stool strains ofC. difficile were isolated in 2.2% where as when toxin was detectable, the isolation rate varied from 17% to 36%. Furthermore, there was a correlation between toxin titre in stool filtrate and production of cytotoxinin vitro by the correspondingC. difficile strains. Five clostridial strains, not belonging to the speciesC. difficile, were found to produce typical cytotoxinin vitro. However, five strains identified asC. difficile by biochemical reactions and gas liquid chromatography, did not produce an extracellular cytotoxin. The antibiotic susceptibility patterns of theClostridium strains were investigated. No correlation was recognized between antibiotic resistance of isolatedClostridium strains and the AAD-inducing antibiotic penicillins and linco/clindamycin. Neither did cases of relapse of diarrheal disease after vancomycin treatment harbourC. difficile strains with increased resistance to vancomycin. It is concluded that the pathogenesis of antibiotic-associated enterocolitis is more complex than a mere intestinal overgrowth of resistant strains ofC. difficile.