title: Release of membrane vesicles containing endotoxic lipopolysaccharide in Escherichia coli O157:H7 clinical isolates.
abstract: Membrane vesicles released by E. coli O157:H7 strains were investigated by immuno-electron microscopy using anti-O157 antibody. Anti-O157 antibody enhanced the negative-staining of vesicles and we found numerous small vesicles clearly formed around bacterial cells. An immunogold-electron microscopic examination confirmed that lipopolysaccharide (LPS) including the O-side chain is present on the surface of the vesicles. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the purified vesicles showed that the vesicles contained LPS consisting of a lipid-A and an O polysaccharide. In addition, the endotoxic activity of the vesicle was confirmed by a limulus test. These results suggest that the vesicles may play an important role in the pathogenesis of Escherichia coli O157:H7.
authors.affiliation: Faculty of Health and Welfare, Seinan Jogakuin University Kitakyushu, Fukuoka, Japan. Yuko.Meno@ma6.seikyou.ne.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Meno
authors.forename: S
authors.initials: S
authors.lastname: Fujimoto
authors.forename: K
authors.initials: K
authors.lastname: Horikawa
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D003092:Colitis / Q000382:microbiology; D004731:Endotoxins / Q000378:metabolism*; D004927:Escherichia coli Infections / Q000382:microbiology*; D019453:Escherichia coli O157 / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity / Q000648:ultrastructure*; D006471:Gastrointestinal Hemorrhage / Q000382:microbiology; D006801:Humans; D008033:Limulus Test / Q000379:methods; D008070:Lipopolysaccharides / Q000276:immunology / Q000378:metabolism*; D008854:Microscopy, Electron; D019081:O Antigens / Q000276:immunology
chemical_list: D004731:Endotoxins; D008070:Lipopolysaccharides; D019081:O Antigens