Adhesion and ultrastructural properties of human enterotoxigenic Escherichia coli producing colonization factor antigens III and IV.

摘要: Human enterotoxigenic Escherichia coli (ETEC) producing colonization factor antigen III (CFA/III) and surface antigens 4, 5, 6 (CS4, CS5, CS6) of CFA/IV were examined ultrastructurally for ability to adhere human small intestinal enterocytes cultured mucosa. Strains serotypes O25:H-, O25:H42, O167:H5 CFA/III plus CS6, CS4 CS5 respectively, showed good adhesion (1.8 4.2 bacteria per brush border) mucosa, whereas variants lacking these or only CS6 nonadherent (0 0.03 bacterium border). By electron microscopy, CFA/III, CS4, appeared as morphologically distinct rodlike fimbriae: was 7 8 nm in diameter, 5 diameter. unusual that it be composed two fine fibrils arranged a double-helical structure. difficult characterize but possibly has very fibrillar specific fimbrial staining immunoelectron microscopy. shown promote mucosal ETEC; similar role the could not confirmed. ETEC strains O27:H7, O27:H20, O148:H28, O159:H20 which produced (1.6 3.0 border), lacked 0.01 These strains, however, also antigens, addition probably represent additional responsible observed adhesive properties serotypes.