杭州地区耐甲氧西林表皮葡萄球菌对利奈唑胺耐药机制研究  

Linezolid resistance in methicillin-resistant Staphylococcus epidermidis strains isolated in Hangzhou ;area

作　　者：汪强[1] 王寅[1] 刘建芳[1] 陈雪静[1] 黄晨静[1] 孙爱华[2] 严杰[3] 

机构地区：[1]浙江中医药大学附属第二医院检验科,杭州310005 [2]杭州医学院,310053 [3]浙江大学医学院病原生物学系,杭州310058

出　　处：《中华微生物学和免疫学杂志》2016年第8期593-597,共5页Chinese Journal of Microbiology and Immunology

基　　金：国家自然科学基金（81271893）;浙江省自然科学基金（LY16H270012）;浙江省教育厅科研项目（Y201328999）

摘　　要：目的：了解杭州地区耐甲氧西林表皮葡萄球菌（ MRSE）临床菌株对利奈唑胺耐药机制。方法2013年5月—2015年4月从杭州地区多家医院败血症、泌尿道感染、感染性胸膜炎患者标本中分离出23株对利奈唑胺耐药表皮葡萄球菌（ LRSE ）。采用 E-test测定13种抗生素对上述LRSE菌株的最低抑菌浓度（ MIC）。采用脉冲场凝胶电泳（ PFGE）和聚类分析确定上述LRSE菌株的同源性。采用PCR及其产物测序了解上述LRSE菌株23S rRNA 基因第5功能区G2576T突变和cfr基因与利奈唑胺耐药的关系。结果23株LRSE中,15株利奈唑胺MIC〉256μg/ml,8株利奈唑胺MIC分别为6或8μg/ml,但均对苯唑西林和头孢西丁耐药。利奈唑胺高耐药（ MIC〉256μg/ml） LRSE菌株中,LRSE1和LRSE2、LRSE3~LRSE6、LRSE9~LRSE12分别为来自同一医院的同一克隆系。所有LRSE菌株均携带cfr基因,但利奈唑胺高耐药（ MIC〉256μg/ml）的15株LRSE菌株同时存在23S rRNA基因第5功能区G2576T突变,但利奈唑胺低耐药（ MIC=6或8μg/ml）的8株LRSE菌株则否。结论本地区分离的LRSE菌株对利奈唑胺耐药水平差异较大,但分布较广且均为耐甲氧西林凝固酶阴性葡萄球菌。 LRSE对利奈唑胺耐药性与其23S rRNA基因第5功能区G2576T突变和携带cfr基因有关。Objective To investigate the mechanism of linezolid resistance in methicillin-resistant Staphylococcus epidermidis （ MRSE） strains isolated in Hangzhou area. Methods Twenty-three linezolid-re-sistant Staphylococcus epidermidis （ LRSE） strains were isolated from the patients with septicaemia, urinary tract infection or infectious pleuritis in several hospitals in Hangzhou area during May, 2013 to April, 2015. The minimal inhibition concentrations （ MICs） of thirteen different antibiotics against the LRSE strains were detected by using E-test. Pulsed-field gel electrophoresis （ PFGE） and cluster analysis were performed for homology analysis. Correlations between linezolid resistance in the LRSE strains and G2576T mutation at theⅤ functional region of 23S rRNA gene or cfr gene were determined by PCR and sequencing analysis. Re-sults The MICs of linezolid to 15 LRSE strains were higher than 256 μg/ml while to the other 8 LRSE strains were 6 or 8 μg/ml. All of the 23 LRSE strains were resistant to both oxacillin and cefoxitin. Among the LRSE strains with high linezolid MICs （MIC〉256 μg/ml）, LRSE1 and LRSE2, LRSE3-LRSE6 and LRSE9-LRSE12 respectively belonged to the same clone line and came from the same hospital. All of the 23 LRSE strains carried the cfr gene. Moreover, the G2576T mutation at theⅤfunctional region of 23S rRNA gene was detected in the 15 LRSE strains with high linezolid MICs （ MIC〉256 μg/ml ） , but not in the 8＆amp;nbsp;strains with lower linezolid MICs （ MIC=6 or 8 μg/ml） . Conclusion There are significant differences in linezolid resistance among LRSE strains isolated in Hangzhou area. The LRSE strains are methicillin-resist-ant coagulase negative Staphylococcus （ MRCNS） strains and widely distributed. The linezolid resistance in LRSE strains is related to the G2576T mutation at theⅤfunctional region of 23S rRNA gene and cfr gene.

关 键 词：表皮葡萄球菌 利奈唑胺 耐药 23S RRNA基因 cfr基因 

分 类 号：R446.5[医药卫生—诊断学]