title: Intestinal colonization and adhesion by enteroxigenic Escherichia coli: ultrastructural observations on adherence to ileal epithelium of the pig.
abstract: Colonization of pig ileum by enterotoxigenic Escherichia coli that were enteropathogenic for pigs but that lacked K88 antigen (K88-) resulted in morphological characteristics similar to those reported for K88+ strains. Strains of enterotoxigenic E. coli from three different K88-serotypes adhered to the villous epithelium. In sections examined by transmission electron microscopy, adherent bacteria were separated from each other and from epithelial microvilli by peribacterial electron-lucent regions. The enterotoxigenic E. coli had appendages that extended into these regions. The appendages were morphologically characteristic for each strain. It is possible that these appendages were pili, polysaccharide K antigens, or structures resulting from some interaction between pili and polysaccharide. Certain  pili or pilus-like structures may be virulence attributes that facilitate adhesion of enterotoxigenic E. coli to the intestinal epithelium.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial; D004768:Enterotoxins; D004926:Escherichia coli / Q000254:growth & development* / Q000276:immunology / Q000648:ultrastructure; D007082:Ileum / Q000382:microbiology; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000648:ultrastructure; D013552:Swine
chemical_list: D000942:Antigens, Bacterial; D004768:Enterotoxins