We determined the clinical and molecular epidemiology of emerging nosocomial vancomycin-resistant Enterococcus faecium (VREfm)–causing serious bloodstream infections (BSIs) and the correlations between antibiotic resistance and virulence determinants among isolates. All isolates were confirmed by molecular methods (16SrRNA and E. faecium ddl genes) and tested for disk diffusion. PCR was used to detect aac(6′)-aph(2″), vanA and vanB resistance genes, and asa1, cylA, ace, esp, gelE and hyl virulence genes. VREfm and high-level gentamicin-resistant (HLGR) representative isolates were selected to characterize by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Of 173 isolates, 73 (42.2%), 146 (84.4%), and 0 (0.0%) were vanA-containing VREfm, aac(6′)-aph(2″)–positive HLGR, and vanB-positive. Independent predictors of VREfm infection were hematological malignancies (P = 0.001) and previous hospitalizations (P = 0.007). Observed mortality rate was 34.7%. Independent predictors of BSI-related mortality were endotracheal intubations (P < 0.001), gastrointestinal diseases (P = 0.002), and pulmonary disease (P < 0.001). All VREfm were resistant to vancomycin, teicoplanin, ciprofloxacin, and erythromycin. The esp, hyl, ace, asa1, cylA, and gelE genes were detected at 55.9, 22.5, 2.9, 2.3, 1.7, and 1.2%, respectively. The esp gene was significantly associated with VREfm compared to VSEfm (P = 0.001). PFGE analysis revealed 23 clones, with 7 major clones. The MLST analysis revealed the following five sequence types: ST80, ST17, ST117, ST132, and ST280, all belonging to CC17. The emergence and expansion of VREfm CC17 with limited antibiotic options in our hospital present a serious public health menace and represent challenges to infection control.

我们确定了新兴的耐万古霉素的粪便肠球菌（VREfm）的临床和分子流行病学-导致严重的血液感染（BSI）以及分离株之间抗生素耐药性和毒力决定因素之间的相关性。所有分离物均通过分子方法（16SrRNA和粪肠球菌ddl基因）进行了确认，并进行了磁盘扩散测试。PCR用于检测aac（6'）-aph（2''），van A和van B耐药基因以及asa1，cylA，ace，esp，gelE和hyl毒力基因。选择VREfm和高水平的耐庆大霉素（HLGR）代表性菌株，通过脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）进行表征。在173个分离株中，有73个（42.2％），146个（84.4％）和0（0.0％）为含vanA的VREfm，aac（6'）-aph（2″）– HLGR阳性和vanB阳性。VREfm感染的独立预测因素是血液系统恶性肿瘤（P = 0.001）和以前的住院治疗（P = 0.007）。观察到的死亡率为34.7％。与BSI相关的死亡率的独立预测因素是气管插管（P <0.001），胃肠道疾病（P = 0.002）和肺部疾病（P = 0.002）。P < 0.001）。所有VREfm均对万古霉素，替考拉宁，环丙沙星和红霉素有耐药性。的ESP，HYL，ACE，ASA1，cylA，和格勒物在55.9，22.5，2.9，2.3，1.7和1.2％分别检测到的基因。该ESP基因显著与VREFM相比VSEfm（相关联的P= 0.001）。PFGE分析揭示了23个克隆，其中7个为主要克隆。MLST分析揭示了以下五个序列类型：ST80，ST17，ST117，ST132和ST280，均属于CC17。VREfm CC17的出现和扩展，在我们医院中使用的抗生素选择有限，给公众健康带来了严重威胁，并给感染控制带来了挑战。