title: Afa, a diffuse adherence fibrillar adhesin associated with enteropathogenic Escherichia coli.
abstract: O55 is one of the most frequent enteropathogenic Escherichia coli (EPEC) O serogroups implicated in infantile diarrhea in developing countries. Multilocus enzyme electrophoresis analysis showed that this serogroup includes two major electrophoretic types (ET), designated ET1 and ET5. ET1 corresponds to typical EPEC, whilst ET5 comprises strains with different combinations of virulence genes, including those for localized adherence (LA) and diffuse adherence (DA). Here we report that ET5 DA strains possess a DA adhesin, designated EPEC Afa. An 11.6-kb chromosomal region including the DA adhesin operon from one O55:H(-) ET5 EPEC strain was sequenced and found to encode a protein with 98% identity to AfaE-1, an adhesin associated with uropathogenic E. coli. Although described as an afimbrial adhesin, we show that both AfaE-1 and EPEC Afa possess fine fibrillar structures. This is the first characterization and demonstration of an Afa adhesin associated with EPEC.
authors.affiliation: Laboratório Especial de Microbiologia, Instituto Butantan, São Paulo, Brazil. keller@usp.br
authors.forename: Rogéria
authors.initials: R
authors.lastname: Keller
authors.forename: Juana G
authors.initials: JG
authors.lastname: Ordoñez
authors.forename: Rosana R
authors.initials: RR
authors.lastname: de Oliveira
authors.forename: Luiz R
authors.initials: LR
authors.lastname: Trabulsi
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Baldwin
authors.forename: Stuart
authors.initials: S
authors.lastname: Knutton
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D001422:Bacterial Adhesion; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry; D004926:Escherichia coli / Q000472:pathogenicity*; D005816:Genetic Complementation Test; D006801:Humans; D005810:Multigene Family; D016366:Open Reading Frames
chemical_list: D018830:Adhesins, Escherichia coli; C108509:AfaE protein, E coli; D004269:DNA, Bacterial