Evolving oxazolidinone resistance mechanisms in a worldwide collection of enterococcal clinical isolates: results from the SENTRY Antimicrobial Surveillance Program
Evolving oxazolidinone resistance mechanisms in a worldwide collection of enterococcal clinical isolates: results from the SENTRY Antimicrobial Surveillance Program
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DOI：
10.1093/jac/dky188
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发表时间：
2018-09-01
影响因子：
5.2
通讯作者：
Mendes, R. E.
中科院分区：
文献类型：
--
作者：
Deshpande, L. M.;Castanheira, M.;Mendes, R. E.
目的：本研究评价全球收集的肠球菌临床分离株中恶唑烷酮耐药机制。方法：采用MALDI-TOF MS法对2008- 2016年SENTRY抗菌药物监测项目（SENTRY Antimicrobial Surveillance Program，SENTRY 2008- 2016）中分离的26 648株肠球菌进行鉴定，采用微量肉汤稀释法测定MIC。筛选利奈唑胺MIC>= 4 mg/L的分离株的耐药机制。结果：36株粪肠球菌和66株屎肠球菌的利奈唑胺MIC>= 4 mg/L（占监测肠球菌的0.38%）。E.粪肠球菌的利奈唑胺MIC范围为4-16 mg/L，而E.屎肠的含量较高（4-64 mg/L）。九E来自亚太地区、北美、拉丁美洲和欧洲的26株（72.2%）粪肠球菌分离株具有G2576 T突变，optrA被检测到; 3株分离株还产生Cfr [泰国（1）]或Cfr（B）[巴拿马（2）]。所有E.屎肠分离株具有G2576 T变异，而来自美国的三个分离株同时存在CFR（B）。optrA基因在22和3株E.粪便，分别。一个分离物在质粒和染色体上有杂交信号。optrA的遗传背景各不相同。E.在不同的地理区域检测到属于同一克隆复合体的粪菌。此外，遗传上不同的分离物从爱尔兰有一个相同的optrA上下文，表明质粒dissemination.Conclusions：在23 S rRNA的改变仍然是主要的恶唑烷酮耐药机制在大肠杆菌。faecium，optrA在E.粪便。这些结果表明optrA的全球传播，并保证监测。
Objectives: This study evaluated the oxazolidinone resistance mechanisms among a global collection of enterococcal clinical isolates. The epidemiology of optrA-carrying isolates and the optrA genetic context were determined.Methods: Enterococcal isolates (26 648) from the SENTRY Antimicrobial Surveillance Program (2008-16) were identified by MALDI-TOF MS and MICs were determined by broth microdilution. Isolates with linezolid MICs of >= 4 mg/L were screened for resistance mechanisms. Isolates carrying optrA had their genome sequenced for genetic context and epidemiology information.Results: Thirty-six Enterococcus faecalis and 66 Enterococcus faecium had linezolid MICs of >= 4 mg/L (0.38% of surveillance enterococci). E. faecalis had a linezolid MIC range of 4-16 mg/L, while E. faecium displayed higher values (4-64 mg/L). Nine E. faecalis had G2576T mutations and optrA was detected in 26 (72.2%) isolates from the Asia-Pacific region, North America, Latin America and Europe; 3 isolates also produced Cfr [Thailand (1)] or Cfr(B) [Panama (2)]. All E. faecium isolates had G2576T alterations, while three isolates from the USA had concomitant presence of cfr(B). The optrA gene was plasmid - and chromosome-located in 22 and 3 E. faecalis, respectively. One isolate signalled hybridization on plasmid and chromosome. The genetic context of optrA varied. E. faecalis belonging to the same clonal complex were detected in distinct geographical regions. Also, genetically distinct isolates from Ireland had an identical optrA context, indicating plasmid dissemination.Conclusions: Alterations in 23S rRNA remained the main oxazolidinone resistance mechanism in E. faecium, while optrA prevailed in E. faecalis. These results demonstrate global dissemination of optrA and warrant surveillance for monitoring.