Kuriyama Tomoari, Williams David W, Patel Mital, Lewis Michael A O, Jenkins Lynda E, Hill Dylan W, Hosein Ian K
Department of Oral Surgery, Medicine and Pathology, Dental School, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XY, UK 2Department of Infection Prevention and Control, Cardiff and Vale NHS Trust, Heath Park, Cardiff CF14 4XN, UK.
J Med Microbiol. 2003 Sep;52(Pt 9):821-827. doi: 10.1099/jmm.0.05123-0.
The present study describes the first molecular characterization of environmental and clinical isolates of vancomycin-resistant enterococci (VRE) in Wales. Over a 3-month period (May-July 2000), 134 isolates of VRE (89 Enterococcus faecium and 45 Enterococcus faecalis) were isolated from the patient environment of the University Hospital of Wales (UHW) in Cardiff, Wales, UK. In addition, over the same time-period, 24 clinical isolates of VRE (20 isolates of E. faecium and four isolates of E. faecalis) were obtained from 14 patients. All study isolates were subjected to PFGE typing and their van genotypes were determined by using multiplex PCR. The vanA PCR product (231 bp) was evident in 146 (92 %) of 158 VRE isolates; the remaining 12 isolates (8 %) were positive for the vanB gene. All isolates of E. faecalis were found to be vanA-positive. In total, 16 PFGE banding profiles (pulsotypes) were observed for environmental isolates of E. faecium, whilst eight pulsotypes were found for isolates of E. faecalis. Some of these pulsotypes were isolated from multiple sites, whereas others were more restricted in their distribution. Eleven pulsotypes were evident for clinical isolates and eight of these (representing 11 isolates) were also encountered in environmental isolates. Eleven clinical isolates of E. faecium (55 %) shared an identical pulsotype that was not detected in environmental isolates. These results demonstrate a heterogeneous environmental population of VRE and an association of certain strains with clinical isolates. Predominance of a single pulsotype (not detected in the environment) amongst clinical isolates suggests non-environmental transmission between patients.
本研究描述了威尔士耐万古霉素肠球菌（VRE）环境分离株和临床分离株的首次分子特征。在2000年5月至7月的3个月期间，从英国威尔士加的夫威尔士大学医院（UHW）的患者环境中分离出134株VRE（89株粪肠球菌和45株屎肠球菌）。此外，在同一时期，从14名患者中获得了24株VRE临床分离株（20株粪肠球菌和4株屎肠球菌）。所有研究分离株均进行了脉冲场凝胶电泳（PFGE）分型，并通过多重聚合酶链反应（PCR）确定其van基因型。在158株VRE分离株中的146株（92%）中可见vanA PCR产物（231 bp）；其余12株（8%）vanB基因呈阳性。所有屎肠球菌分离株均为vanA阳性。粪肠球菌环境分离株共观察到16种PFGE条带图谱（脉冲型），而屎肠球菌分离株观察到8种脉冲型。其中一些脉冲型从多个部位分离得到，而其他脉冲型分布更局限。临床分离株有11种脉冲型，其中8种（代表11株）也在环境分离株中出现。11株粪肠球菌临床分离株（55%）共享一种在环境分离株中未检测到的相同脉冲型。这些结果表明VRE在环境中存在异质性群体，且某些菌株与临床分离株有关联。临床分离株中单一脉冲型（在环境中未检测到）占优势表明患者之间存在非环境传播。
