title: Serotypes of CNF1-producing Escherichia coli strains that cause extraintestinal infections in humans.
abstract: The O:K:H serotypes of 137 necrotoxigenic Escherichia coli (NTEC) producing the cytotoxic necrotizing factor type 1 (CNF1) isolated from human extraintestinal infection were determined. Although NTEC producing CNF1 belonged to 58 different serotypes, only 10 of them accounted for 54% of strains. The most common serotypes, in order of frequency, were: O4:K?:H5, O6:K13:H1, O83:K1:H31, O75:K95:H5, O2:K1:H6, O2:K7:H-, O75:K1:H7, O2:K?:H1, O4:K12:H1 and O22:K13:H1. CNF1 strains of serotypes O2:K7:H- and O4:K12:H1 express P-fimbriae, whereas CNF1 strains of serotypes O2:K?:H1, O2:K1:H6 and O75:K95:H5 possess the adhesin responsible for MRHA type III. Among CNF1 strains of serotype O4:K?:H5 there exist some that express P-fimbriae and others that possess MRHA type III. Lastly, the majority of CNF1 strains of serotypes O6:K13:H1, O22:K13:H1, O75:K1:H7 and O83:K1:H31 do not express P-fimbriae nor the adhesin responsible to MRHA type III. Our results show that extraintestinal infections are caused by a limited number of virulent clones, as suggested by the theory of special pathogenicity.
authors.affiliation: Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago, Lugo, Spain.
authors.forename: J E
authors.initials: JE
authors.lastname: Blanco
authors.forename: J
authors.initials: J
authors.lastname: Blanco
authors.forename: M
authors.initials: M
authors.lastname: Blanco
authors.forename: M P
authors.initials: MP
authors.lastname: Alonso
authors.forename: W H
authors.initials: WH
authors.lastname: Jansen
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003603:Cytotoxins / Q000378:metabolism*; D004926:Escherichia coli / Q000145:classification* / Q000378:metabolism* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology*; D010861:Fimbriae, Bacterial / Q000378:metabolism; D006367:HeLa Cells; D006384:Hemagglutination; D006460:Hemolysin Proteins / Q000378:metabolism; D006801:Humans; D018933:Pili, Sex / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism; D012703:Serotyping; D013030:Spain; D014709:Vero Cells; D014774:Virulence
chemical_list: D018829:Adhesins, Bacterial; D001427:Bacterial Toxins; D003603:Cytotoxins; D006460:Hemolysin Proteins; D011971:Receptors, Immunologic; C037872:pili, bacterial receptor