ENTEROTOXIGENIC BACTEROIDES-FRAGILIS IN HUNGARY

Bacteroides fragilis, which constitutes about 1% of the colonic microf lora in humans, is the most frequent anaerobic species involved in abs cesses, soft-tissue infections and bacteraemias. Additionally, enterot oxigenic strains of B. fragilis have been demonstrated to be associate d with diarrhoea in domestic animals and humans. Enterotoxigenic strai ns of B. fragilis derived from stool specimens and from infectious pro cesses produce a toxin which induces a cytotoxic response in HT-29 col on carcinoma cells. These findings prompted us to investigate the prev alence of enterotoxigenic strains of B. fragilis isolated from various clinical specimens in Hungary. A total of 134 strains were collected from different clinical settings: 74 from infectious processes, 20 fro m stools of healthy subjects and 40 from the faeces of patients with d iarrhoea where no other enteric pathogen could be isolated. Cell cultu re assays with HT-29 cells were performed on the filtered culture supe rnatants of the isolated strains. Of the 134 strains, 34 (25.3%) prove d toxin-positive. The presence of free toxin was also observed in 20 o f 50 (40%) of the faeces of adults with diarrhoea. (C) 1997 Academic P ress.