title: High diversity of extended-spectrum beta-lactamases in Escherichia coli isolates from Italian broiler flocks.
abstract: We characterized 67 Escherichia coli isolates with reduced susceptibility to cefotaxime or ceftiofur obtained from healthy broilers housed in five Italian farms. The bla(CTX-M-1), bla(CTX-M-32) and bla(SHV-12) beta-lactamase genes were identified on IncI1, IncN, or IncFIB plasmids. Considerable genetic diversity was detected among the extended-spectrum beta-lactamase (ESBL)-producing isolates, and we identified indistinguishable strains in unrelated farms and indistinguishable plasmids in genetically unrelated strains. The detection of highly mobile plasmids suggests a potential animal reservoir for beta-lactamase genes.
authors.affiliation: Department of Veterinary Disease Biology, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark. vbo@life.ku.dk
authors.forename: Valeria
authors.initials: V
authors.lastname: Bortolaia
authors.forename: Luca
authors.initials: L
authors.lastname: Guardabassi
authors.forename: Marcello
authors.initials: M
authors.lastname: Trevisani
authors.forename: Magne
authors.initials: M
authors.lastname: Bisgaard
authors.forename: Luciano
authors.initials: L
authors.lastname: Venturi
authors.forename: Anders Miki
authors.initials: AM
authors.lastname: Bojesen
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D018550:Cephalosporin Resistance / Q000235:genetics; D002645:Chickens / Q000382:microbiology*; D004197:Disease Reservoirs / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology / Q000635:transmission; D029968:Escherichia coli Proteins / Q000235:genetics*; D005798:Genes, Bacterial; D014644:Genetic Variation; D006801:Humans; D007558:Italy; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; D001618:beta-Lactamases