title: Antibiotic-resistant Enterococcus faecalis in abattoir pigs and plasmid colocalization and cotransfer of tet(M) and erm(B) genes.
abstract: This study was conducted to determine plasmid colocalization and transferability of both erm(B) and tet(M) genes in Enterococcus faecalis isolates from abattoir pigs in Canada. A total of 124 E. faecalis isolates from cecal contents of abattoir pigs were examined for antibiotic susceptibility. High percentages of resistance to macrolides and tetracyclines were found. Two predominant multiresistance patterns of E. faecalis were examined by PCR and sequencing for the presence of genes encoding antibiotic resistance. Various combinations of antibiotic resistance genes were detected; erm(B) and tet(M) were the most common genes. Plasmid profiling and hybridization revealed that both genes were colocated on a ~9-kb transferable plasmid in six strains with the two predominant multiresistant patterns. Plasmid colocalization and cotransfer of tet(M) and erm(B) genes in porcine E. faecalis isolates indicates that antibiotic coselection and transferability could occur via this single genetic element. To our knowledge, this is the first report on plasmid colocalization and transferability of erm(B) and tet(M) genes in E. faecalis on a mobile genetic element of ~9 kb. Physical linkage between important antibiotic resistance determinants in enterococci is of interest for predicting potential transfer to other bacterial genera.
authors.affiliation: Swine Infectious Disease Research Center, Department of Pathology and Microbiology, University of Montreal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Quebec, Canada.
authors.forename: Cindy-Love
authors.initials: CL
authors.lastname: Tremblay
authors.forename: Ann
authors.initials: A
authors.lastname: Letellier
authors.forename: Sylvain
authors.initials: S
authors.lastname: Quessy
authors.forename: Danielle
authors.initials: D
authors.lastname: Daignault
authors.forename: Marie
authors.initials: M
authors.lastname: Archambault
mesh_terms: D000003:Abattoirs; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D002170:Canada / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D005516:Food Microbiology; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D008826:Microbial Sensitivity Tests; D013552:Swine / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C083138:Tet M resistance protein, Bacteria