耐碳青霉烯类肺炎克雷伯菌耐消毒剂基因检测及同源性分析

Detection and homology analysis of disinfectant resistance genes in carba-penem-resistant Klebsiella pneumoniae

摘要:

目的 探讨武汉地区临床分离的耐碳青霉烯类肺炎克雷伯菌(CRKP)中耐消毒剂基因的携带状况及耐消毒剂基因携带菌株的同源性, 为有效预防和控制CRKP传播提供理论依据。 方法 收集2018—2019年武汉市3所三级医院临床住院患者分离的非重复性CRKP菌株, 采用最低抑菌浓度测定方法对药敏结果进行复核, 采用实时荧光定量聚合酶链反应(RT-PCR)检测耐消毒剂基因qacEΔ1、cepA, 采用脉冲场凝胶电泳(PFGE)对同时携带qacEΔ1和cepA基因的CRKP菌株进行同源性分析。 结果 共收集62株CRKP, 77.42%来源于重症监护病房(ICU), 40.32%来自痰标本。所有CRKP均为多重耐药菌, 对厄他培南、阿莫西林/克拉维酸、头孢唑林、头孢他啶、头孢曲松5种抗生素的耐药率均为100%, 对临床其他常见抗菌药物也呈现高度耐药。耐消毒剂基因检出率为95.16%(59/62), 其中qacEΔ1、cepA基因检出率分别为64.52%(40/62)、91.94%(57/62), 38株(61.29%)同时检出qacEΔ1和cepA。PFGE结果显示, 38株CRKP可分为A~K共11个型别, 以E型为主, 占42.11%(16株)。 结论 武汉地区CRKP菌株耐药形势严峻, 广泛携带耐消毒剂基因, 存在不同医院、不同科室间的克隆传播, 应加强流行病学监控, 合理使用消毒剂。

Abstract:

Objective To investigate the carrying status of disinfectant resistance genes in clinically isolated carbapenem-resistant Klebsiella pneumoniae (CRKP) and the homology of strains that carried disinfectant resistance genes in Wuhan City, and provide theoretical basis for the effective prevention and control of CRKP transmission. Methods Non-repetitive CRKP strains isolated from hospitalized patients in three tertiary hospitals in Wuhan City from 2018 to 2019 were collected. Antimicrobial susceptibility were tested by minimum inhibitory concentration (MIC). Disinfectant resistance gene qacEΔ1 and cepA were detected by real-time polymerase chain reaction (RT-PCR). Homology of CRKP strains carrying both qacEΔ1 and cepA genes was analyzed by pulsed-field gel electrophoresis (PFGE). Results A total of 62 CRKP strains were collected, 77.42% were from intensive care unit (ICU), 40.32% were isolated from sputum specimens. All CRKP strains were multidrug-resistant, with resistance rates to ertapenem, amoxicillin/clavulanic acid, cefazolin, ceftazidime, and ceftriaxone being 100% and high resis-tance to other frequently used antimicrobial agents. The detection rate of disinfectant resistance genes was 95.16% (59/62), among which qacEΔ1 and cepA genes were 64.52% (40/62) and 91.94% (57/62), respectively, with 38 strains (61.29%) detected both qacEΔ1 and cepA genes. PFGE results showed that 38 CRKP strains can be divided into 11 types (from A to K), with type E being the major type, accounting for 42.11% (n=16). Conclusion Antimicrobial resistance of CRKP strains in Wuhan is severe. Strains carry disinfectant resistance genes widely. There is clonal transmission among different hospitals and departments. Epidemiological monitoring should be streng-thened, and disinfectant should be used rationally.