利奈唑胺体外诱导粪肠球菌耐药株23S rRNA V区基因突变位点分析  

Genetic mutations in the V domain of the 23S ribosomal RNA gene of linezolid-resistant Enterococcus faecalis

作　　者：李多云[1,2] 余治健[1,2] 徐俊[1,2] 刘晓军[1,2] 邓名贵[1,2] 潘伟光[1,2] 郑金鑫[1,2] 陈重[1,2] 邓启文[1,2] 

机构地区：[1]广东医学院附属深圳市南山区人民医院感染科,广东深圳518052 [2]深圳市内源性感染诊治重点实验室,广东深圳518052

出　　处：《中国病原生物学杂志》2014年第4期316-317,375,共3页Journal of Pathogen Biology

基　　金：深圳市科技创新委员会项目(No.JCYJ20130402151227180;2012028;2012021;201303179);深圳市医学重点学科经费资助

摘　　要：目的阐明体外诱导利奈唑胺耐药粪肠球菌的核糖体23SrRNA V区基因位点变异特征。方法收集1株血流感染的粪肠球菌和1株粪肠球菌质控菌ATCC29212(编号分别为F3和F4菌株,均为利奈唑胺敏感株),通过体外浓度倍增法诱导利奈唑胺耐药;挑取单克隆,经E-test条测定MIC值,获得各菌株的耐药浓度梯度;提取耐药菌株基因组DNA,PCR扩增23SrRNA V区基因,扩增产物经测序后与野生株比较,获得V区的突变位点。结果经体外多步法诱导利奈唑胺耐药的不同MIC值粪肠球菌共13株。PCR测序分析2株母株均无变异位点,23SrRNA V区的突变位点主要是G2576U,此外还有T2504A、G2505A、C2610A、C2424U。结论体外多步法可诱导粪肠球菌利奈唑胺耐药,耐药机制与23SrRNA V区位点突变密切相关,突变位点随着MIC值的增高而增多。Objective To investigate the characteristics of genetic mutations in the V domain of the 23Sribosomal RNA gene of linezolid-resistant Enterococcus faecalis in vitro. Methods A strain of E.faecalis isolated from clinical samples（designated F3）and a strain of E.faecalis（designated F4）that is commonly used as a quality control strain in antibiotic tests（ATCC 29212）were obtained.Linezolid（LZD）resistance was induced in vitro via serial dilution.The 2parent strains,F3and F4,and LZD-resistant strains were isolated and their MIC values were determined using an E-test. The V domain of the 23Sribosomal RNA gene of these strains was then amplified and sequenced. Results LZD resistance was induced in vitroin 13strains of E.faecalis with different MIC values.PCR and sequencing indicated that the V domain of the 23Sribosomal RNA gene of these strains contained multiple point mutations,including G2576U,T2504A, G2505A,C2610A,and C2424U. Conclusion LZD resistance can be induced in E.faecalis in vitro.LZD resistance in E.faecalis was closely associated with genetic mutations in the V domain of the 23Sribosomal RNA gene,and the MIC value increased with a larger number of point mutations in the ribosomal RNA gene.

关 键 词：粪肠球菌 利奈唑胺耐药 23S核糖体RNA基因 

分 类 号：R378.1[医药卫生—病原生物学]