Prevalence of vancomycin-variable Enterococcus faecium (VVE) among vanA-positive sterile site isolates and patient factors associated with VVE bacteremia

Vancomycin-variable enterococci (VVE) are vanA-positive, vancomycin-susceptible enterococci with the ability to revert to a vancomycin-resistant phenotype on exposure to vancomycin. We sought to assess the prevalence of VVE and to determine clinical characteristics of patients infected with VVE. We prospectively collected Enterococcus faecium sterile site isolates from Toronto Invasive Bacterial Diseases Network hospitals from January 2015 to June 2016 and calculated VVE (defined as vanA-positive, vancomycin-susceptible isolates) prevalence among vanA-containing isolates. We performed chart reviews of VVE and vancomycin-resistant E. faecium (VRE) bacteremias identified from January 2012 to June 2016, and on a random sample of patients with bacteremia due to vanA/vanB-negative, vancomycin-susceptible enterococci (VSE) from January 2015 to June 2016. Clinical characteristics were compared and factors associated with mortality assessed. Because of the potential reversion from VVE to VRE, p...

万古霉素可变型肠球菌（Vancomycin-variable enterococci, VVE）是一类vanA基因阳性、对万古霉素敏感的肠球菌，在接触万古霉素后可逆转恢复为万古霉素耐药表型。本研究旨在评估VVE的流行率，并明确感染VVE患者的临床特征。
我们于2015年1月至2016年6月期间，从多伦多侵袭性细菌疾病网络（Toronto Invasive Bacterial Diseases Network）所属医院前瞻性收集了粪肠球菌（Enterococcus faecium）的无菌部位分离株，并在携带vanA基因的分离株中计算了VVE（定义为vanA基因阳性、万古霉素敏感的分离株）的流行率。
我们对2012年1月至2016年6月期间检出的VVE及万古霉素耐药粪肠球菌（vancomycin-resistant E. faecium, VRE）菌血症患者的病历进行了回顾性审查，并对2015年1月至2016年6月期间因vanA/vanB基因双阴性、万古霉素敏感肠球菌（vancomycin-susceptible enterococci, VSE）引发菌血症的患者随机抽样开展病历审查。
研究对各组患者的临床特征进行了比较，并评估了与死亡率相关的影响因素。鉴于VVE存在向VRE表型逆转的潜在可能，p...