DETECTION OF TOXIN PRODUCTION BY BACTEROIDES-FRAGILIS - ASSAY DEVELOPMENT AND SCREENING OF EXTRAINTESTINAL CLINICAL ISOLATES

Strains of Bacteroides fragilis that produce an extracellular 20-kD he at-labile toxin have been epidemiologically associated with diarrheal disease. To standardize detection of the B. fragilis toxin (BFT), a de tailed description of the methods for identifying BFT production by B. fragilis strains is reported, To further study the role of toxigenic strains of B. fragilis in clinical disease, extraintestinal clinical i solates that were recovered at an urban east-coast hospital were evalu ated. Four (6.2%) of 65 isolates produced BFT. Three cases in which BF T-producing B. fragilis were isolated from extraintestinal sites are r eported. In contrast to studies from Japan that have reported BFT prod uction by 23.4% of extraintestinal B. fragilis isolates, we conclude t hat BFT-producing strains of B. fragilis are infrequently associated w ith extraintestinal B. fragilis disease at our institution. Additional study will be necessary to better define the importance of BFT produc tion in human disease due to B. fragilis.