Molecular characterization of the fragilysin pathogenicity islet of enterotoxigenic Bacteroides fragilis.

ABSTRACT: Enterotoxigenic strains of Bacteroides fragilis produce an extracellular metalloprotease toxin (termed fragilysin) which is cytopathic to intestinal epithelial cells and induces fluid secretion and tissue damage in ligated intestinal loops. We report here that the fragilysin gene is contained within a small genetic element termed the fragilysin pathogenicity islet. The pathogenicity islet of B. fragilis VPI 13784 was defined as 6,033 bp in length and contained nearly perfect 12-bp direct repeats near its ends. Sequencing across the ends of the pathogenicity islet from two additional enterotoxigenic strains, along with PCR analysis of 20 additional enterotoxigenic strains, revealed that the islet is inserted at a specific site on the B. fragilis chromosome. The site of integration in three

SUBMITTER: Moncrief JS 

PROVIDER: S-EPMC108111 | biostudies-literature | 1998 Apr

REPOSITORIES: biostudies-literature