Release of Membrane Vesicles Containing Endotoxic Lipopolysaccharide in Escherichia coli O157:H7 Clinical Isolates
2000; Wiley; Volume: 44; Issue: 4 Linguagem: Inglês
10.1111/j.1348-0421.2000.tb02494.x
ISSN1348-0421
AutoresYuko Meno, Shuji Fujimoto, Kazumi Horikawa, Shin�ichi Yoshida,
Tópico(s)Viral gastroenteritis research and epidemiology
ResumoMembrane 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.
Referência(s)