title: Multiple-antibiotic resistance of Enterococcus faecalis and Enterococcus faecium from cecal contents in broiler chicken and turkey flocks slaughtered in Canada and plasmid colocalization of tetO and ermB genes.
abstract: This study was conducted to characterize the antimicrobial resistance determinants and investigate plasmid colocalization of tetracycline and macrolide genes in Enterococcus faecalis and Enterococcus faecium from broiler chicken and turkey flocks in Canada. A total of  387 E. faecalis and E. faecium isolates were recovered from poultry cecal contents from five processing plants. The percentages of resistant E. faecalis and E. faecium isolates, respectively, were 88.1 and 94% to bacitracin, 0 and 0.9% to chloramphenicol, 0.7 and  14.5% to ciprofloxacin, 72.6 and 80.3% to erythromycin, 3.7 and 41% to flavomycin, 9.6 and 4.3% (high-level resistance) to gentamicin, 25.2 and 17.1% (high-level resistance) to kanamycin, 100 and 94% to lincomycin, 0 and 0% to linezolid, 2.6 and 20.5% to nitrofurantoin, 3 and 27.4% to penicillin,  98.5 and 89.7% to quinupristin-dalfopristin, 7 and 12.8% to salinomycin, 46.7 and 38.5% (high-level resistance) to streptomycin, 95.6 and 89.7% to tetracycline, 73 and 75.2% to tylosin, and 0 and 0% to vancomycin. One predominant multidrug-resistant phenotypic pattern was identified in both  E. faecalis and E. faecium (bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, tetracycline, and tylosin). These isolates were further examined by PCR and sequencing for the genes encoding their antimicrobial resistance. Various combinations of vatD, vatE, bcrR,  bcrA, bcrB, bcrD, ermB, msrC, linB, tetM, and tetO genes were detected, and ermB, tetM, and bcrB were the most common antimicrobial resistance genes identified. For the first time, plasmid extraction and hybridization revealed colocalization of tetO and ermB  genes on a ca. 11-kb plasmid in E. faecalis isolates, and filter mating experiments demonstrated its transferability. Results indicate that the intestinal enterococci of healthy poultry, which can contaminate poultry meat at slaughter, could be a reservoir for quinupristin-dalfopristin,  bacitracin, tetracycline, and macrolide resistance genes.
authors: GREMIP/Research Center in Infectiology of Pork, Department of Pathology and Microbiology, 3200 Sicotte Street, Saint-Hyacinthe, Quebec, Canada.
authors: Cindy-Love
authors: CL
authors: Tremblay
authors: Ann
authors: A
authors: Letellier
authors: Sylvain
authors: S
authors: Quessy
authors: Martine
authors: M
authors: Boulianne
authors: Danielle
authors: D
authors: Daignault
authors: Marie
authors: M
authors: Archambault
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002170:Canada / Q000453:epidemiology; D002432:Cecum / Q000382:microbiology; D002645:Chickens / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D005516:Food Microbiology; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D014422:Turkeys / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents