158株耐多药结核分枝杆菌对利奈唑胺耐药及相关基因突变情况研究  

Analysis of the prevalence of linezolid resistance and mutations conferring linezolid resistance in multidrug resistant Myeobacterium tuberculosis isolates from China

作　　者：王前[1] 宋媛媛[1] 王玉峰[1] 逄宇[1] 赵雁林[1] 

机构地区：[1]中国疾病预防控制中心结核病预防控制中心办公室国家结核病参比实验室,北京102206

出　　处：《中国防痨杂志》2016年第9期712-717,共6页Chinese Journal of Antituberculosis

基　　金：基金项目：“十二五”国家科技重大专项（2013ZX0003-003）

摘　　要：【摘要】目的分析我国耐多药结核分枝杆菌菌株对利奈唑胺的耐药率，探究结核分枝杆菌对利奈唑胺耐药相关基因的突变特征。方法作者于2013年10月采用直接抽选法，从401株来自于2007年全国结核病耐药性基线调查的耐多药结核分枝杆菌菌株中随机抽取158株，分为耐多药组（107／158，67．7％）、前广泛耐药组（41／158，26．0％）和广泛耐药组（10／158，6．3％）；采用微孔板稀释法检测其对利奈唑胺的最低抑菌浓度（minimal inhibitory concentrataion，MIC），以结核分枝杆菌标准株H37Rv（ATCC27249）作为对照，当MIC高于临界浓度时，判定为结核分枝杆菌对利奈唑胺耐药。同时对利奈唑胺耐药的结核分枝杆菌相关基因23SrRNA、rplC和rplD进行测序，分析其突变特征；采用Fisher确切概率法及卡方检验统计不同组别间利奈唑胺耐药率的差别，以P〈O．05为差异有统计学意义。结果158株耐多药菌株对利奈唑胺的总耐药率为10．8％（17／158）。其中10株广泛耐药菌株中有6株对利奈唑胺耐药（6／10），明显高于耐多药组（5．6％，6／107）和前广泛耐药组（12．2％，5／41），经Fisher确切概率法检验差异均有统计学意义（P〈0．001；P=0．004）。在17株利奈唑胺耐药菌株中，共发现5株（29．4％）在23srRNA或（和）rplC基因发生突变，同时首次鉴定到rplG基因His155Asp突变可能与低水平利奈唑胺耐药（MIC=2μg／ml）相关。结论广泛耐多药结核分枝杆菌对利奈唑胺的耐药率明显高于耐多药和前广泛耐药结核分枝杆菌；23SrRNA和rplC基因突变可能与利奈唑胺耐药性相关。Objective To explore the prevalence of linezolid （Lzd） resistance among rnuhidrug resistant （MDR） Mycobacterium tuberculosis isolates from China, and to investigate the characteristics of mutations in genes conferring linezolid resistance. Methods A total of 158 MDR tuberculosis （TB） isolates, including 107 （67.7%） MDR-TB, 41 （26.0%） pre-extensively drug-resistant TB （pre-XDR）, and 10 （6.3 %） extensively drug resistant TB isolates, were used in this study. The broth dilution method was used to determine minimal inhibitory concentra- tions （MIC） of M. tuberculosis isolates against linezolid （Lzd）. The reference isolate H37Rv （ATCC 27249） was used as a control. Lzd resistance was declared if the MIC value of the M. tuberculosis isolate was higher than the cut off value of Lzd. In addition, the 23S rRNA, rplC and rplD genes conferring Lzd resistance were sequenced in all isolates. Fisher＇s exact test was performed to compare the proportions of Lzd resistance among different groups, and differences were considered significant when P〈0.05. Results 10. 8% （17/158） of the 158 MI）R tuberculosis isolates were Lzd-resistant. A higher frequency of Lzd-resistant isolates was identified among extensively drug resistant （XDR） M. tuberculosis isolates （6/10） than among MDR （5.6%, 6/107） and pre-XDR （12.2%, 5/41） isolates, and Fisher＇s exact test revealed that the difference was significant （P〈0. 001 for MDR group; P=0.00/i for preXDR group）. In addition, only 5 （29.4%） of 17 Lzd-resistant isolates harbored mutations in 23S rRNA and/or rplC. A novel non synonymous substitution His155Asp in rplC was identified as a potential contributor to low level I.zd resistance （2μg/ml） in M. tuberculosis for the first time. Conclusion The prevalence of I.zd resis tahoe among XDR isolates was significantly higher than that of MDR isolates. In addition, genetic mutations located in 235 rRNA and rplC were associated with Lzd resistance in M. tuberculosis.

关 键 词：分枝杆菌 结核 恶唑烷酮类 利奈唑胺 结核 抗多种药物性 基因 细菌 突变 因果律 

分 类 号：R52[医药卫生—内科学]