Swine Infectious Disease Research Center, Department of Pathology and Microbiology, University of Montreal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Quebec, Canada.
J Food Prot. 2012 Sep;75(9):1595-602. doi: 10.4315/0362-028X.JFP-12-047.
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.
本研究旨在确定来自加拿大屠宰场猪的粪肠球菌分离株中 erm(B)和 tet(M)基因的质粒共定位和可转移性。对来自屠宰场猪盲肠内容物的 124 株粪肠球菌进行了抗生素敏感性检测。发现对大环内酯类和四环素类的耐药率很高。通过 PCR 和测序，对两种主要的粪肠球菌多耐药模式进行了基因编码抗生素耐药性的检测。检测到各种抗生素耐药基因的组合；erm(B)和 tet(M)是最常见的基因。质粒图谱分析和杂交显示，在具有两种主要多耐药模式的 6 株菌中，这两个基因位于一个约 9kb 的可转移质粒上。粪肠球菌分离株中 tet(M)和 erm(B)基因的质粒共定位和共转移表明，抗生素的共选择和可转移性可能通过这一单一遗传元件发生。据我们所知，这是首次在粪肠球菌中关于 erm(B)和 tet(M)基因在约 9kb 的移动遗传元件上的质粒共定位和可转移性的报告。肠球菌中重要抗生素耐药决定因素的物理连锁关系对于预测其向其他细菌属的潜在转移具有重要意义。
