Kobayashi K, Rao M, Keis S, Rainey F A, Smith J M, Cook G M
Department of Microbiology, Otago School of Medical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand.
J Antimicrob Chemother. 2000 Sep;46(3):405-10. doi: 10.1093/jac/46.3.405.
This study was conducted to determine the prevalence of vancomycin-resistant enterococci (VRE) in the stools of hospitalized patients with possible antibiotic-associated diarrhoea. From 176 faecal samples collected during 1997 and 1998, 66 strains of enterococci were recovered using vancomycin enrichment techniques. Only six of these displayed reduced susceptibility to vancomycin (MIC 8-12 mg/L). All VRE were positive for the presence of the vanC gene. Based on motility, pigment production and automated Gram-positive identification (GPI Vitek card), four of these six VRE isolates were identified as Enterococcus gallinarum. The remaining two isolates were non-motile and therefore were considered to be Enterococcus faecium. However, 16S rDNA sequence analysis and positive methyl-alpha-D-glucopyranoside tests indicated that they were non-motile species of E. gallinarum. This is consistent with the intrinsic, low-level vanC-1-mediated resistance associated with this species. Pulsed-field gel electrophoresis analysis comparisons between the VRE indicated genetic relatedness between some strains. This work confirms that vancomycin-resistant E. faecium and Enterococcus faecalis are rare in New Zealand.
本研究旨在确定可能患有抗生素相关性腹泻的住院患者粪便中耐万古霉素肠球菌（VRE）的流行情况。在1997年和1998年收集的176份粪便样本中，使用万古霉素富集技术分离出66株肠球菌。其中只有6株对万古霉素的敏感性降低（MIC为8 - 12 mg/L）。所有VRE的vanC基因检测均为阳性。根据运动性、色素产生和自动革兰氏阳性菌鉴定（GPI Vitek卡），这6株VRE分离株中有4株被鉴定为鹑鸡肠球菌。其余2株分离株无运动性，因此被认为是粪肠球菌。然而，16S rDNA序列分析和α - D - 甲基吡喃葡萄糖苷阳性试验表明它们是无运动性的鹑鸡肠球菌。这与该菌种固有的、由vanC - 1介导的低水平耐药性一致。VRE之间的脉冲场凝胶电泳分析比较表明一些菌株之间存在遗传相关性。这项工作证实了耐万古霉素的粪肠球菌和屎肠球菌在新西兰很少见。
