Akpaka Patrick E, Kissoon Shivnarine, Jayaratne Padman
Department of Paraclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago.
Department of Pathology and Molecular Medicine, McMaster University, 1280 Main Street W., Hamilton, ON, Canada L8S 4L8.
Adv Med. 2016;2016:8762691. doi: 10.1155/2016/8762691. Epub 2016 May 19.
Geographic spread of vancomycin-resistant enterococci (VRE) clones in cities, countries, or even continents has been identified by molecular techniques. This study aimed at characterizing virulent genes and determining genetic relatedness of 45 VRE isolates from Trinidad and Tobago using molecular tools, including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE), and Random Amplification Polymorphic DNA (RAPD). The majority (84%) of the isolates were Enterococcus faecium possessing vanA gene while the rest (16%) were Enterococcus faecalis possessing vanB. The esp gene was found in all 45 VRE isolates while hyl genes were found only in E. faecium species. The E. faecium species expressed five distinct PFGE patterns. The predominant clones with similar or common patterns belonged to clones one and three, and each had 11 (29%) of the VRE isolates. Plasmid content was identified in representative isolates from each clonal group. By contrast, the E. faecalis species had one PFGE pattern suggesting the presence of an occult and limited clonal spread. The emergence of VRE in the country seems to be related to intra/interhospital dissemination of an epidemic clone carrying the vanA element. Therefore, infection control measures will be warranted to prevent any potential outbreak and spread of VRE in the country.
通过分子技术已确定耐万古霉素肠球菌（VRE）克隆在城市、国家甚至各大洲的地理传播情况。本研究旨在利用分子工具，包括聚合酶链反应、脉冲场凝胶电泳（PFGE）和随机扩增多态性DNA（RAPD），对来自特立尼达和多巴哥的45株VRE分离株的毒力基因进行表征并确定其遗传相关性。大多数分离株（84%）为携带vanA基因的粪肠球菌，其余（16%）为携带vanB的屎肠球菌。在所有45株VRE分离株中均发现了esp基因，而hyl基因仅在粪肠球菌中发现。粪肠球菌表现出五种不同的PFGE模式。具有相似或共同模式的主要克隆属于克隆一和克隆三，每个克隆均有11株（29%）VRE分离株。在每个克隆组的代表性分离株中鉴定了质粒含量。相比之下，屎肠球菌有一种PFGE模式，表明存在隐匿且有限的克隆传播。该国VRE的出现似乎与携带vanA元件的流行克隆在医院内/医院间传播有关。因此，有必要采取感染控制措施以防止该国VRE的任何潜在暴发和传播。
