Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil.
J Hosp Infect. 2011 Sep;79(1):70-4. doi: 10.1016/j.jhin.2011.04.016. Epub 2011 Jul 7.
Enterococci have been implicated in severe human infections as a consequence of associated determinants of virulence and antimicrobial resistance. The majority of vancomycin-resistant Enterococcus faecium (VRE(fm)) connected to outbreaks worldwide pertains to the clonal complex 17 (CC17). In Brazil, the majority of VRE(fm) involved in outbreaks reported so far are not related to CC17. VRE(fm) strains responsible for an outbreak and sporadic cases in hospitals located in the city of Campinas, Brazil, were compared to other VRE(fm) strains in the country. Twenty-two out of 23 E. faecium were vancomycin-resistant and harboured the vanA gene. One vancomycin-susceptible E. faecium (VSE(fm)) strain was included in this study because it was isolated from a patient who one week later harboured a VRE(fm). All strains, except VSE, showed the same alteration in the VanA element characterised by deletion of the left extremity of the transposon and insertion of IS1251 between the vanS and vanH genes. Genes codifying virulence factors such as collagen-adhesin protein, enterococcal surface protein and hyaluronidase were detected in the VRE(fm) and VSE(fm) studied. Both pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) revealed that VRE(fm) and VSE(fm) strains have a clonal relationship. New sequence types (STs) were identified by MLST as ST447, ST448, ST478 and ST412 but all belonged to the CC17. The present study revealed that VRE(fm) outbreaks in Brazil were caused by strains that did not share a common evolutionary history, and that VRE(fm) strains belonging to CC17 could be predominant in Brazil as in other countries.
肠球菌已被认为是与毒力和抗药性相关决定因素有关的严重人类感染的病原体。与世界各地爆发相关的大多数万古霉素耐药肠球菌（VRE(fm)）都属于克隆复合体 17（CC17）。在巴西，迄今为止与爆发相关的大多数 VRE(fm)与 CC17 无关。在巴西坎皮纳斯市的医院中爆发和散发性病例的 VRE(fm)菌株与该国的其他 VRE(fm)菌株进行了比较。23 株屎肠球菌中有 22 株对万古霉素耐药，并且携带 vanA 基因。本研究还包括一株对万古霉素敏感的屎肠球菌（VSE(fm))，因为它是从一周后携带 VRE(fm)的患者中分离出来的。所有菌株（VSE 除外）均显示出 VanA 元素的相同改变，其特征为转座子的左侧末端缺失，并在 vanS 和 vanH 基因之间插入 IS1251。研究的 VRE(fm)和 VSE(fm)中检测到编码胶原黏附蛋白、肠球菌表面蛋白和透明质酸酶等毒力因子的基因。脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）均显示 VRE(fm)和 VSE(fm)菌株具有克隆关系。MLST 鉴定出了新的序列类型（ST），如 ST447、ST448、ST478 和 ST412，但均属于 CC17。本研究表明，巴西的 VRE(fm)爆发是由没有共同进化史的菌株引起的，而属于 CC17 的 VRE(fm)菌株可能在巴西和其他国家一样占主导地位。
