title: Analysis of antimicrobial resistance genes detected in multiple-drug-resistant Escherichia coli isolates from broiler chicken carcasses.
abstract: Multi-drug-resistant (MDR) bacteria in food animals are a potential problem in both animal and human health. In this study, MDR commensal Escherichia coli isolates from poultry were examined. Thirty-two E. coli isolates from broiler carcass rinses were selected based on their resistance to aminoglycosides, β-lactams, chloramphenicols, tetracyclines, and sulfonamide antimicrobials. Microarray analysis for the presence of antimicrobial resistance and plasmid genes identified aminoglycoside [aac(6), aac(3), aadA, aph, strA, and strB], β-lactam (bla(AmpC), bla(TEM), bla(CMY), and bla(PSE-1)), chloramphenicol (cat, flo, and cmlA), sulfamethoxazole (sulI and sulII), tetracycline [tet(A), tet(C), tet(D), and tetR], and trimethoprim (dfrA) resistance genes. IncA/C plasmid core genes were detected in 27 isolates, while IncHI1 plasmid genes were detected in one isolate, indicating the likely presence of these plasmids. PCR assays for 18 plasmid replicon types often associated with MDR in Enterobacteriaceae also detected one or more replicon types in all 32 isolates. Class I integrons were investigated by PCR amplification of the integrase I gene, intI1, and the cassette region flanked by conserved sequences. Twenty-five isolates were positive for the intI1 gene, and class I integrons ranging in size from ~1,000 to 3,300 bp were identified in 19 of them. The presence of class I integrons, IncA/C plasmid genes, and MDR-associated plasmid replicons in the isolates indicates the importance of these genetic elements in the accumulation and potential spread of antimicrobial resistance genes in the microbial community associated with poultry.
authors.affiliation: Bacterial Epidemiology and Antimicrobial Resistance Research Unit, US Department of Agriculture, Agricultural Research Service, Athens, Georgia 30605, USA.
authors.forename: Lashanda M
authors.initials: LM
authors.lastname: Glenn
authors.forename: Mark D
authors.initials: MD
authors.lastname: Englen
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Lindsey
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Frank
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Turpin
authors.forename: Mark E
authors.initials: ME
authors.lastname: Berrang
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Meinersmann
authors.forename: Paula J
authors.initials: PJ
authors.lastname: Fedorka-Cray
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Frye
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002645:Chickens; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D032023:Integrons; D046228:Microarray Analysis; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents