汉中地区耐亚胺培南铜绿假单胞菌耐药机制及脉冲场凝胶电泳分型  

Mechanisms of imipenem resistance and molecular epidemiology in Pseudomonas aeruginosaisolates in Hangzhong area and the PFGE genotyping

作　　者：张樱[1] 蔺咏梅[2] 王克[3] 瞿婷婷[4] 柴阳[3] 李晓波[3] 辜依海[3] 

机构地区：[1]解放军总医院微生物科,北京100853 [2]汉中3201医院感染性疾病科,陕西汉中723000 [3]汉中3201医院检验科,陕西汉中723000 [4]浙江大学医学院附属第一医院传染科,浙江杭州310003

出　　处：《中华医院感染学杂志》2013年第8期1753-1755,共3页Chinese Journal of Nosocomiology

摘　　要：目的探讨汉中地区耐亚胺培南铜绿假单胞菌的耐药机制,为有效控制多药耐药铜绿假单胞菌感染提供依据。方法采用琼脂稀释和Etest法对汉中地区3201医院2006年1月-2008年3月临床分离的70株耐亚胺培南铜绿假单胞菌进行耐药性分析;双纸片协同法和Etest法检测金属酶;聚合酶链反应(PCR)检测β-内酰胺酶基因和oprD2基因;用实时定量PCR方法(qRT-PCR)检测oprD2、ampC基因的表达;脉冲场凝胶电泳(PFGE)分析菌株同源性。结果 70株耐亚胺培南铜绿假单胞菌对多黏菌素、氨曲南、头孢他啶的有较高的敏感性;仅1株产IMP-9型金属酶;65株菌未表达oprD2;4株菌过表达ampC基因;基因测序分析62株菌的oprD2基因均在同一位点正向插入序列ISpa1328;PFGE分型显示,耐亚胺培南铜绿假单胞菌在院内以单克隆流行为主。结论 70株耐亚胺培南铜绿假单胞菌在同一所医院多个科室的单克隆播散,是汉中地区近两年来铜绿假单胞菌对亚胺培南耐药的主要原因,插入序列ISpa1328引起的OprD2的缺失,是汉中地区铜绿假单胞菌对亚胺培南耐药的主要机制。OBJECTIVE To characterize the mechanism contributing to imipenem resistance mechanism in Pseudomonas aeruginosa clinical isolates in Hanzhong area in order to provide evidence for the effective control of the multidrug-resistant P.aeruginosa infections.METHODS A total of 70 imipenem-resistant P.aeruginosa isolates were identified in 3201 hospitals in Hangzhong area between Jan,2006 and Mar,2008.Antibiotics susceptibilities testing were determined on Mueller-Hinton agar by agar dilution or Etest methods.Double disk diffusion test and Etest were performed to detect the Metallo-β-lactamase（MBL）.PCR was used to amplify the β-lactamase gene and oprD2 gene.and the qRT-PCR was employed to analyze oprD2 and ampC expression level.Colonial morphotype was typed by pulsed field gel electrophoresis（PFGE）.RESULTS The 70 strains of imipenem-resistant P.aeruginosa showed relatively higher susceptibility to polymyxin,aztreonam,and ceftazidime.Only 1 strain was detected for IMP-9.Of the 70 isolates,65 isolates lost OprD2 expression.4 isolates overproduced ampC.Sequencing analysis showed that the forward insertion sequence ISpa1328 was inserted into at the same locus of oprD2 in the 62 isolates without OprD2 expression.PFGE indicated that most of isolates belonged to monoclone.CONCLUSION The epidemiology of 71 strains of imipenem-resistant P.aeruginosa is from monoclonal dissemination in the departments of the same hospital,which is the leading cause of the imipenem resistance in the Hanzhong area in the past two years,and the ISpa1328 inserted into oprD2 gene leads to the imipenem resistance in these isolates.

关 键 词：亚胺培南 铜绿假单胞菌 同源性 OprD2缺失 插入序列 

分 类 号：R378.991[医药卫生—病原生物学]