昆明地区耐碳青霉烯类抗生素铜绿假单胞菌的分子流行病学特点及耐药特征分析

Molecular epidemiological and drug resistance characteristics of carbapenem-resistant Pseudomonas aeruginosa in Kunming

目的研究耐碳青霉烯类抗生素铜绿假单胞菌分子流行病学规律及耐药机制,为临床预防和治疗铜绿假单胞菌的感染提供理论依据。方法对多中心收集的耐碳青霉烯类抗生素铜绿假单胞菌(carbapenems-resistant Pseudomonas aeruginosa,CRPA)开展多位点序列分型(multilocus sequence typing,MLST)和遗传信息研究,并对碳青霉烯酶基因与外膜孔蛋白OprD编码基因进行序列分析。结果多位点序列分型方法将81株CRPA分为36个ST型,总体以ST3390(41.98%,34/81)为主,其中有5种为新发现的ST型别;CRPA菌株中碳青霉烯酶基因的检出率较高(65.43%,53/81),尿液标本检出率最高(80.00%,28/35),其中IMP、VIM和NDM型碳青霉烯酶基因检出率分别为37.04%、27.16%和1.23%,未检测到KPC、GES、SPM和OXA-40型碳青霉烯酶基因;oprD基因的序列比对分析发现,高达96.29%(78/81)CRPA临床分离株发生了各种类型的突变,以单个或者多个碱基的插入或缺失为主(76.54%,62/81)。结论81株CRPA主要的耐药机制为膜孔蛋白基因突变和产碳青霉烯酶;存在ST3390克隆株的局部流行,应加强医院感染防控措施,防止暴发流行。

Objective To explore the molecular epidemiology and drug resistance mechanism of carbapenem resistant Pseudomonas aeruginosa(CRPA),and to provide theoretical basis for clinical prevention and treatment of Pseudomonas aeruginosa infection.Methods Multilocus sequence typing(Multilocus Sequence Typing,MLST)and genetic information of carbapenem resistant Pseudomonas aeruginosa collected from multiple centers were studied,and the sequences of carbapenemase gene and outer membrane porin OprD coding gene were analyzed.Results 81 strains of CRPA were divided into 36 ST types by multilocus sequence typing.The ST3390(41.98%,34/81)was the main type,and five ST types were newly discovered.The carbapenemase gene in CRPA strains was higher(65.43%,53/81),especially in urine samples(80.00%,28/35),of which IMP,VIM,and NDM carbapenemase enzyme genes were 37.04%,27.16%,and 1.23%,respectively,and KPC,GES,SPM,and OXA-40 carbapenemase genes were not detected.Up to 96.29%(78/81)of the CRPA clinical isolates had various types of mutations in the gene oprD,which were dominated by single or multiple base insertions or deletions(76.54%,62/81).Conclusion The main drug resistance mechanisms of 81 strains of CRPA are porin gene mutation and carbapenemase production.There is a local epidemic of ST3390 clone,prevention and control measures should be strengthened to prevent outbreaks.