title: Isolation of K88 antigen variants (ab, ac, ad) from porcine enterotoxigenic Escherichia coli belonging to different serotypes.
abstract: Fimbriae isolation by means of thermal shock was applied to fifteen K88-positive (three K88ab, nine K88ac and three K88ad) Escherichia coli reference strains belonging to serotypes O8:K87, O32, O45, O138:K81, O141:K85, O147:K89, O149:K91, and O157, as well as to ten K88-positive enterotoxigenic strains isolated from porcine diarrhea in Spain, all of them belonging to the O149 serogroup. Fimbriae were removed from the bacterial cells by thermal shock at 60 C and then precipitated using ammonium sulfate. The final amount of K88 antigen and the purification degree were not related to the serogroup of the bacteria or to the antigen variant but were related to the buffer used for isolation. Phosphate buffer containing urea was shown to be more effective than Tris-HCl for isolation of K88 antigen. The molecular weights by SDS-PAGE for K88ab, K88ac, and K88ad were 28.5, 29.2, and 31.0 kDa, respectively. All enterotoxigenic E. coli strains isolated in Spain showed the K88ac variant.
authors.affiliation: Departamento de Microbiología y Parasitología, Facultade de Veterinaria, Universidade de Santiago de Compostela, Lugo, Spain.
authors.forename: E A
authors.initials: EA
authors.lastname: González
authors.forename: F
authors.initials: F
authors.lastname: Vázquez
authors.forename: J
authors.initials: J
authors.lastname: Ignacio Garabal
authors.forename: J
authors.initials: J
authors.lastname: Blanco
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D000954:Antigens, Surface / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D001422:Bacterial Adhesion; D003967:Diarrhea / Q000209:etiology / Q000662:veterinary; D004768:Enterotoxins / Q000096:biosynthesis; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000276:immunology*; D004927:Escherichia coli Infections / Q000209:etiology / Q000662:veterinary; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000276:immunology; D014644:Genetic Variation; D008970:Molecular Weight; D012703:Serotyping; D013030:Spain; D013552:Swine; D013553:Swine Diseases / Q000209:etiology
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C026888:K88 antigen, E coli; D036781:Fimbriae Proteins