Jahangiri S, Talebi M, Eslami G, Pourshafie M R
Department of Microbiology, Pasteur Institute of Iran, Tehran, Iran.
Indian J Med Microbiol. 2010 Oct-Dec;28(4):337-41. doi: 10.4103/0255-0857.71828.
The purpose of the present study was to perform a molecular epidemiological survey by investigating the antibiotic resistance and the presence of known virulence factors in Enterococcus faecium isolates in Iran. The data collected from this study would allow us to control the spread and develop strategies for treatment of the enterococcal infections.
In this study, 156 vancomycin-sensitive E. faecium (VSEF; 58) and vancomycin-resistant E. faecium (VREF; 98) samples were isolated from clinical specimen and sewage treatment plants (STPs). These isolates were screened for the presence of genes encoding for aggregation substance (asa1), cytolysin (cyl), enterococcal surface protein (esp), gelatinase (gelE) and hyaluronidase (hyl) by polymerase chain reaction (PCR).
Although significantly different, the results showed the presence of hyl and esp genes in both clinical (41 and 75%, respectively) and sewage (3.2 and 41%, respectively) isolates. Sensitivity of all isolates to seven antibiotics was examined. The results of the clinical isolates showed that the majority of esp positive isolates were also resistant to vancomycin, ciprofloxacin and erythromycin. Furthermore, cyl, gelE and asa1 were not found in either clinical or STP isolates. Finally, we determined the distinct types of isolates using Pulse Field Gel Electrophoresis (PFGE), which confirmed that most of the isolates were clonally unrelated.
Our results demonstrated that higher number of the clinical E. faecium isolates carried virulence genes than the isolates from STP. Finally, the lack of the genes in clinical and STP isolates confirmed that these genes do not transfer horizontally.
本研究的目的是通过调查伊朗粪肠球菌分离株的抗生素耐药性和已知毒力因子的存在情况，开展分子流行病学调查。本研究收集的数据将有助于我们控制肠球菌感染的传播并制定治疗策略。
在本研究中，从临床标本和污水处理厂分离出156株万古霉素敏感粪肠球菌（VSEF；58株）和万古霉素耐药粪肠球菌（VREF；98株）样本。通过聚合酶链反应（PCR）筛选这些分离株中是否存在编码聚集物质（asa1）、细胞溶素（cyl）、肠球菌表面蛋白（esp）、明胶酶（gelE）和透明质酸酶（hyl）的基因。
尽管存在显著差异，但结果显示临床分离株（分别为41%和75%）和污水分离株（分别为3.2%和41%）中均存在hyl和esp基因。检测了所有分离株对七种抗生素的敏感性。临床分离株的结果表明，大多数esp阳性分离株也对万古霉素、环丙沙星和红霉素耐药。此外，在临床或污水处理厂分离株中均未发现cyl、gelE和asa1。最后，我们使用脉冲场凝胶电泳（PFGE）确定了不同类型的分离株，证实大多数分离株在克隆上不相关。
我们的结果表明，临床粪肠球菌分离株携带毒力基因的数量高于污水处理厂分离株。最后，临床和污水处理厂分离株中缺乏这些基因证实这些基因不会水平转移。
