title: Prevalence of ColV Plasmid-Linked Genes and In Vivo Pathogenicity of Avian Strains of Escherichia coli.
abstract: Avian pathogenic Escherichia coli (APEC) causes extraintestinal infections in birds, leading to an increase in the cost of poultry production. The ColV plasmid-linked genes iroN, ompT, hlyF, iss, and iutA have previously been suggested to be predictors of the virulence of APEC. In this research, we analyzed the frequencies of these genes in a Brazilian collection of E. coli isolated from birds with colibacillosis (APEC) and from apparently healthy birds (avian fecal [A(fecal)]), as well as from the litter of poultry houses of apparently healthy flocks (avian litter [A(litter)]). All the isolates that harbored ompT also harbored hlyF, so they were considered as one trait for statistical analysis. The relationship between in vivo virulence in 1-day-old chicks, expressed as a pathogenicity score, and the number of genes in each isolate showed that isolates with less than two of the four genes were rarely pathogenic, while most pathogenic isolates contained two or more genes. Nevertheless, about half of the nonpathogenic isolates also harbored two or more genes, in agreement with previous observations that commensal E. coli isolates from the birds' microbiota can serve as a reservoir of virulence genes. Thus, the pentaplex polymerase chain reaction can be used to indicate that a strain carrying none or only one gene would be nonpathogenic, but it cannot be used to indicate that a strain with two to four genes would be an APEC. Isolates allocated to phylogenetic group B2, which is frequently associated with extraintestinal infections, had the highest pathogenicity scores, while isolates allocated to group B1 had the lowest.
authors.affiliation: 1 Departamento de Biofísica, Universidade Federal do Rio Grande do Sul , Porto Alegre, Brazil .|2 Instituto de Pesquisas Veterinárias Desidério Finamor , Eldorado do Sul, Brazil .
authors.forename: Aline Luísa
authors.initials: AL
authors.lastname: de Oliveira
authors.affiliation: 1 Departamento de Biofísica, Universidade Federal do Rio Grande do Sul , Porto Alegre, Brazil .
authors.forename: Débora Assumpção
authors.initials: DA
authors.lastname: Rocha
authors.affiliation: 2 Instituto de Pesquisas Veterinárias Desidério Finamor , Eldorado do Sul, Brazil .
authors.forename: Fabrine
authors.initials: F
authors.lastname: Finkler
authors.affiliation: 2 Instituto de Pesquisas Veterinárias Desidério Finamor , Eldorado do Sul, Brazil .
authors.forename: Lucas Brunelli
authors.initials: LB
authors.lastname: de Moraes
authors.affiliation: 1 Departamento de Biofísica, Universidade Federal do Rio Grande do Sul , Porto Alegre, Brazil .
authors.forename: Nicolle Lima
authors.initials: NL
authors.lastname: Barbieri
authors.affiliation: 1 Departamento de Biofísica, Universidade Federal do Rio Grande do Sul , Porto Alegre, Brazil .
authors.forename: Daniel Brisotto
authors.initials: DB
authors.lastname: Pavanelo
authors.affiliation: 1 Departamento de Biofísica, Universidade Federal do Rio Grande do Sul , Porto Alegre, Brazil .
authors.forename: Cristina
authors.initials: C
authors.lastname: Winkler
authors.affiliation: 2 Instituto de Pesquisas Veterinárias Desidério Finamor , Eldorado do Sul, Brazil .
authors.forename: Tiela Trapp
authors.initials: TT
authors.lastname: Grassotti
authors.affiliation: 2 Instituto de Pesquisas Veterinárias Desidério Finamor , Eldorado do Sul, Brazil .
authors.forename: Kelly Cristina Tagliari
authors.initials: KC
authors.lastname: de Brito
authors.affiliation: 2 Instituto de Pesquisas Veterinárias Desidério Finamor , Eldorado do Sul, Brazil .
authors.forename: Benito Guimarães
authors.initials: BG
authors.lastname: de Brito
authors.affiliation: 1 Departamento de Biofísica, Universidade Federal do Rio Grande do Sul , Porto Alegre, Brazil .
authors.forename: Fabiana
authors.initials: F
authors.lastname: Horn
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001938:Brazil; D002645:Chickens / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology; D060005:Genotyping Techniques; D010447:Peptide Hydrolases / Q000235:genetics; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000235:genetics
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C469922:IroN protein, E coli; C409210:Iss protein, E coli; D011956:Receptors, Cell Surface; C499588:ompT protein, E coli; D010447:Peptide Hydrolases