title: Molecular characterization and clonal relationships among Escherichia coli strains isolated from broiler chickens with colisepticemia.
abstract: This study characterized 52 Escherichia coli isolates from distinct diseased organs of 29 broiler chickens with clinical symptoms of colibacillosis in the Southern Brazilian state of Rio Grande do Sul. Thirty-eight isolates were highly virulent and 14 were virtually avirulent in 1-day-old chicks, yet all isolates harbored virulence factors characteristic of avian pathogenic E. coli (APEC), including those related to adhesion, iron acquisition, and serum resistance. E. coli reference collection phylogenetic typing showed that isolates belonged mostly to group D (39%), followed by group A (29%), group B1 (17%), and group B2 (15%). Phylogenetic analyses using the Amplified Ribosomal DNA Restriction Analysis and pulse-field gel electrophoresis methods were used to discriminate among isolates displaying the same serotype, revealing that five birds were infected with two distinct APEC strains. Among the 52 avian isolates, 2 were members of the pandemic E. coli O25:H4-B2-ST131 clone.
authors.affiliation: 1 Departamento de Biofísica, Universidade Federal do Rio Grande do Sul , Porto Alegre, RS, Brazil .
authors.forename: Nicolle Lima
authors.initials: NL
authors.lastname: Barbieri
authors.forename: Aline Luísa
authors.initials: AL
authors.lastname: de Oliveira
authors.forename: Thiago Moreira
authors.initials: TM
authors.lastname: Tejkowski
authors.forename: Daniel Brisotto
authors.initials: DB
authors.lastname: Pavanelo
authors.forename: Letícia Beatriz
authors.initials: LB
authors.lastname: Matter
authors.forename: Sandra Regina Schincariol
authors.initials: SR
authors.lastname: Pinheiro
authors.forename: Tânia Mara Ibelli
authors.initials: TM
authors.lastname: Vaz
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Nolan
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Logue
authors.forename: Benito Guimarães
authors.initials: BG
authors.lastname: de Brito
authors.forename: Fabiana
authors.initials: F
authors.lastname: Horn
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D001938:Brazil; D002645:Chickens / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000662:veterinary*; D005838:Genotype; D018805:Sepsis / Q000382:microbiology / Q000662:veterinary*; D012703:Serotyping; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D037521:Virulence Factors