...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Clinical Microbiology >Rapid characterization schemes for surveillance isolates of vancomycin-resistant enterococci.
【24h】

Rapid characterization schemes for surveillance isolates of vancomycin-resistant enterococci.

机译：监测耐万古霉素肠球菌分离株的快速表征方案。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Surveillance cultures for vancomycin-resistant enterococci (VRE) and subsequent characterization of the isolates can be extremely burdensome and difficult. Therefore, efficient and reliable schemes for the characterization of surveillance isolates are needed. In this study, a commercial agar (bile esculin azide agar with 6 microg of vancomycin per ml [BEAA]; Remel, Lenexa, Kans.) was used in the initial screening step to establish relatively rapid (i.e., in < or = 24 h from the time of isolation) phenotype-based and PCR-based schemes for the detection and characterization of VRE. The phenotype-based scheme included Gram staining of growth on BEAA and subculture of cocci on sheep blood agar plates for vancomycin disk diffusion and pyrazinamidase (PYR) testing. For the PCR scheme, inocula for van gene detection were taken directly from the BEAA plates. The phenotypic approach was applied to 378 surveillance cultures that yielded growth on BEAA. Gram staining quickly eliminated gram-positive bacilli from further testing, and a negative PYR test classified 25 additional isolates as probable pediococci. A positive PYR test reliably identified 121 single-patient VRE isolates that included 83 Enterococcus faecium, 33 E. gallinarum, and 5 E. casseliflavus strains. The vancomycin inhibition zone size clearly distinguished VanA and VanB strains from VanC strains within 24 h of BEAA isolation. All VanA and VanB strains failed to produce zones of >6 mm, while only one VanC strain produced a zone of < 15 mm. Challenging this phenotypic scheme with 47 stock VRE isolates produced similar findings. In direct PCR analyses, false-negative vanA and vanB results occurred with 12% of the specimens. Many of the false-negative reactions also failed to produce an internal control product, which underscores the need for including control primers when a PCR scheme is used. In summary, the phenotype- and the PCR-based schemes provide efficient methods for characterizing VRE within 24 h of isolation.
机译：耐万古霉素肠球菌（VRE）的监测培养以及分离株的后续表征可能非常繁重且困难。因此，需要一种有效且可靠的方案来表征监视隔离株。在这项研究中，商业琼脂（每毫升含6 ug万古霉素的胆汁七叶叠氮化物琼脂[BEAA]; Remel，Lenexa，堪萨斯州）用于初始筛选步骤，以建立相对较快的速度（即在<或= 24小时内从分离时开始）基于表型和基于PCR的方案来检测和表征VRE。基于表型的方案包括在BEAA上生长的革兰氏染色以及在羊血琼脂板上的球菌的继代培养，以进行万古霉素圆盘扩散和吡嗪酰胺酶（PYR）测试。对于PCR方案，直接从BEAA板中提取用于van基因检测的接种物。该表型方法已应用于378个在BEAA上生长的监测培养物中。革兰氏染色迅速排除了革兰氏阳性杆菌的进一步检测，而PYR阴性则将另外25个分离株归为可能的小球菌。 PYR阳性试验可靠地鉴定出121例单人VRE分离株，其中包括83株粪便肠球菌，33株鸡胆肠球菌和5株卡塞尔夫拉夫菌。在BEAA分离后的24小时内，万古霉素抑制区的大小清楚地将VanA和VanB菌株与VanC菌株区分开。所有VanA和VanB菌株均无法产生> 6 mm的区域，而只有一种VanC菌株所产生的区域<15 mm。用47种VRE分离株对这一表型方案进行挑​​战，产生了相似的发现。在直接PCR分析中，有12％的样本出现假阴性的vanA和vanB结果。许多假阴性反应也未能产生内部对照产物，这强调了在使用PCR方案时需要包括对照引物的情况。总之，基于表型和基于PCR的方案提供了在分离后24小时内表征VRE的有效方法。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号