Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor DE, Malaysia.
Appl Environ Microbiol. 2013 Aug;79(15):4528-33. doi: 10.1128/AEM.00650-13. Epub 2013 May 10.
Vancomycin-resistant enterococci (VRE) have been reported to be present in humans, chickens, and pigs in Malaysia. In the present study, representative samples of VRE isolated from these populations were examined for similarities and differences by using the multilocus sequence typing (MLST) method. Housekeeping genes of Enterococcus faecium (n = 14) and Enterococcus faecalis (n = 11) isolates were sequenced and analyzed using the MLST databases eBURST and goeBURST. We found five sequence types (STs) of E. faecium and six STs of E. faecalis existing in Malaysia. Enterococcus faecium isolates belonging to ST203, ST17, ST55, ST79, and ST29 were identified, and E. faecium ST203 was the most common among humans. The MLST profiles of E. faecium from humans in this study were similar to the globally reported nosocomial-related strain lineage belonging to clonal complex 17 (CC17). Isolates from chickens and pigs have few similarities to those from humans, except for one isolate from a chicken, which was identified as ST203. E. faecalis isolates were more diverse and were identified as ST4, ST6, ST87, ST108, ST274, and ST244, which were grouped as specific to the three hosts. E. faecalis, belonging to the high-risk CC2 and CC87, were detected among isolates from humans. In conclusion, even though one isolate from a chicken was found clonal to that of humans, the MLST analysis of E. faecium and E. faecalis supports the findings of others who suggest VRE to be predominantly host specific and that clinically important strains are found mainly among humans. The infrequent detection of a human VRE clone in a chicken may in fact suggest a reverse transmission of VRE from humans to animals.
万古霉素耐药肠球菌（VRE）已在马来西亚的人类、鸡和猪中报告存在。在本研究中，通过使用多位点序列分型（MLST）方法，对从这些人群中分离出的 VRE 代表性样本进行了相似性和差异性检查。对屎肠球菌（n=14）和粪肠球菌（n=11）分离株的管家基因进行测序，并使用 MLST 数据库 eBURST 和 goeBURST 进行分析。我们在马来西亚发现了 5 种屎肠球菌序列类型（ST）和 6 种粪肠球菌 ST。鉴定出属于 ST203、ST17、ST55、ST79 和 ST29 的屎肠球菌分离株，其中 ST203 在人群中最为常见。本研究中人类屎肠球菌的 MLST 图谱与全球报告的与医院相关的属于克隆复合体 17（CC17）的菌株谱系相似。除了从鸡中分离的一株为 ST203 外，鸡和猪的分离株与人类的分离株相似性很小。屎肠球菌分离株更为多样化，鉴定为 ST4、ST6、ST87、ST108、ST274 和 ST244，这些分离株特定于三种宿主。在人类分离株中检测到属于高风险 CC2 和 CC87 的粪肠球菌。总之，尽管从鸡中分离出一株与人类的克隆，但屎肠球菌和粪肠球菌的 MLST 分析支持其他人的发现，即 VRE 主要以宿主特异性为主，临床上重要的菌株主要存在于人类中。在鸡中很少检测到人类 VRE 克隆，实际上可能表明 VRE 从人类向动物的反向传播。
