Department of Clinical Lab Medicine, Taizhou University affiliated Taizhou Municipal Hospital, Taizhou, PR China.
Department of Urology Surgery, Taizhou University affiliated Taizhou Municipal Hospital, Taizhou, PR China.
J Med Microbiol. 2013 Nov;62(Pt 11):1728-1734. doi: 10.1099/jmm.0.062893-0. Epub 2013 Aug 2.
A total of 69 strains of Escherichia coli from patients in the Taizhou Municipal Hospital, China, were isolated, and 11 strains were identified that were resistant to bacitracin, chloramphenicol, tetracycline and erythromycin. These strains were PCR positive for at least two out of three genes, ybjG, dacC and mdfA, by gene mapping with conventional PCR detection. Conjugation experiments demonstrated that these genes existed in plasmids that conferred resistance. Novel ybjG and dacC variants were isolated from E. coli strains EC2163 and EC2347, which were obtained from the sputum of intensive care unit patients. Genetic mapping showed that the genes were located on 8200 kb plasmid regions flanked by EcoRI restriction sites. Three distinct genetic structures were identified among the 11 PCR-positive strains of E. coli, and two contained the novel ybjG and dacC variants. The putative amino acid differences in the ybjG and dacC gene variants were characterized. These results provide evidence for novel variants of ybjG and dacC, and suggest that multiple drug resistance in hospital strains of E. coli depends on the synergistic function of ybjG, dacC and mdfA within three distinct genetic structures in conjugative plasmids.
从中国泰州市医院的患者中分离出了 69 株大肠杆菌，其中有 11 株对杆菌肽、氯霉素、四环素和红霉素具有耐药性。通过常规 PCR 检测基因图谱，这些菌株的 ybjG、dacC 和 mdfA 三个基因中的至少两个基因呈 PCR 阳性。接合实验表明，这些基因存在于赋予耐药性的质粒中。从 ICU 患者的痰液中分离出了 EC2163 和 EC2347 两株大肠杆菌菌株，从中分离出了新型 ybjG 和 dacC 变体。遗传图谱显示，这些基因位于 EcoRI 限制位点侧翼的 8200 kb 质粒区域。在 11 株 PCR 阳性的大肠杆菌菌株中鉴定出了三种不同的遗传结构，其中两种含有新型 ybjG 和 dacC 变体。对 ybjG 和 dacC 基因变体的假定氨基酸差异进行了表征。这些结果为 ybjG 和 dacC 的新型变体提供了证据，并表明医院大肠杆菌菌株的多重耐药性取决于三种不同遗传结构中 ybjG、dacC 和 mdfA 的协同功能。
