多重耐药铜绿假单胞菌的相关耐药机制研究

The research of resistance mechanism on the multi-drug resistant P. aeruginosa

目的分析我院铜绿假单胞菌的耐药性与耐药机制,为临床抗感染治疗提供理论依据。方法采用K-B法进行体外药敏试验,收集耐碳青霉烯类铜绿假单胞菌60株,检测其主动外排泵表型,PCR扩增其外膜蛋白opr D2基因、金属酶相关基因,PFGE同源性分析等。结果我院耐碳青霉烯类耐药率较高,于2014年达8.3%。6株外排泵表型阳性,IMP阳性32份,VIM阳性16份,IMP和VIM均阳性12份,外膜蛋白Opr D2缺失3株。PFGE同源性分析,结果分为3个型。其中A型有25株,B型有20株,C型有15株。结论我院多重耐药铜绿假单胞菌检出率较高,耐药机制以IMP与VIM为主,同时存在外排泵及外膜蛋白耐药机制,PFGE同源性分析显示我院存在不同克隆株流行,需加强细菌爆发流行防护措施。

Objective To analyze the drug resistance evidences for clinical anti-infection treatment. Methods and resistant mechanism of P. aeruginosa, to provide K-B method was used for atimicrobial susceptibility testing; and 60 stains carbapenem-resistant P. aeruginosa were screened, the active efflux pump phenotype detection was conducted, PCR and DNA sequencing techolology was used to amplify the regulated genes oprD2 outer membrane protein gene and metal enzyme genes; PFGE was used for homology analysis, etc. Results The detection rate of carbapenem-resistant P. aeruginosa was 8.3% in 2014.6 strains were positive of efflux pump phenotype, 32 stains were IMP positive, 16 stains were VIM positive, 12 stains both had IMP and VIM positive, 3 strains were missed outer membrane protein OprD2. The result of PFGE homology analysis showed： 25 strains were type A, 20 strains were type B, and 15 strains were type C. Conclusion The detection rate of carbapenem-resistant P. aeruginosa was high, the maily resistance mechanism was producing metallo-β-lactamase, the main types were IMP and VIM, also existed the efflux pump and outer membrane protein missed, PFGE homology analysis showed there were different cloning epidemic type, so clinical doctors should improve and strength the protective measures to control bacteria epidemic outbreak.