Identification of a Novel Clone, ST736, among Enterococcus faecium Clinical Isolates and Its Association with Daptomycin Nonsusceptibility
Identification of a Novel Clone, ST736, among Enterococcus faecium Clinical Isolates and Its Association with Daptomycin Nonsusceptibility
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DOI：
10.1128/aac.02683-14
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发表时间：
2014-08-01
影响因子：
4.9
通讯作者：
Fallon, John T.
中科院分区：
文献类型：
--
作者：
Wang, Guiqing;Kamalakaran, Sitharthan;Fallon, John T.
肠球菌临床分离株对达托霉素的耐药性仍然很罕见，但在美国和世界范围内的报告越来越多。关于达托霉素不敏感肠球菌临床分离株的遗传相关性、微生物学和临床特征的数据有限。在这项研究中，我们评估了达托霉素不敏感屎肠球菌（DNSE）临床分离株的群体遗传学多位点序列分型（MLST）和全基因组测序分析。42个非重复DNSE分离株和43个随机选择的达托霉素敏感E。粪便分离物包括在分析中。所有E.从2009年5月至2013年12月在纽约市郊区的三级医疗中心从患者中回收粪菌分离物。DNSE分离株的达托霉素MIC范围为6至> 256 μ g/ml。E.通过MLST和基于全基因组序列的分析，在这些临床分离株中鉴定出屎肠球菌（ST 18、ST 412和ST 736）。在42株DNSE分离株中有32株（76.2%）出现新识别的克隆ST 736，而在43株达托霉素敏感的E.粪肠分离株（P < 0.0001）。本报告提供了E.屎肠菌克隆ST 736和达托霉素不敏感。对该新品种的鉴定和推广应用前景进行了展望。屎肠菌克隆及其与达托霉素不敏感性的关联构成了我们医疗中心对患者管理和感染控制的挑战。
Resistance to daptomycin in enterococcal clinical isolates remains rare but is being increasingly reported in the United States and worldwide. There are limited data on the genetic relatedness and microbiological and clinical characteristics of daptomycin-nonsusceptible enterococcal clinical isolates. In this study, we assessed the population genetics of daptomycin-nonsusceptible Enterococcus faecium (DNSE) clinical isolates by multilocus sequence typing (MLST) and whole-genome sequencing analysis. Forty-two nonduplicate DNSE isolates and 43 randomly selected daptomycin-susceptible E. faecium isolates were included in the analysis. All E. faecium isolates were recovered from patients at a tertiary care medical center in suburban New York City from May 2009 through December 2013. The daptomycin MICs of the DNSE isolates ranged from 6 to > 256 mu g/ml. Three major clones of E. faecium (ST18, ST412, and ST736) were identified among these clinical isolates by MLST and whole-genome sequence-based analysis. A newly recognized clone, ST736, was seen in 32 of 42 (76.2%) DNSE isolates and in only 14 of 43 (32.6%) daptomycin-susceptible E. faecium isolates (P < 0.0001). This report provides evidence of the association between E. faecium clone ST736 and daptomycin nonsusceptibility. The identification and potential spread of this novel E. faecium clone and its association with daptomycin nonsusceptibility constitute a challenge for patient management and infection control at our medical center.