医院耐亚胺培南铜绿假单胞菌的耐药机制研究

Resistance Mechanism of Imipenem-resistant Pseudomonas aeruginosa

目的研究医院铜绿假单胞菌(PAE)耐药情况及对亚胺培南的耐药机制分布。方法对医院临床分离的150株非重复铜绿假单胞菌对亚胺培南(IMP)等14种常用抗菌药物的最低抑菌浓度(MIC)进行检测;进一步对耐亚胺培南铜绿假单胞菌(IRPA)64株作为受试株,进行耐药机制表型初筛试验及基因检测。结果 IRPA共64株,占42.6%,其中9株为产金属β-内酰胺酶(MBL)阳性,占试验菌株的14.06%,4株携带VIM基因和3株携带IMP基因,其他为阴性结果;17株主动外排表型筛选阳性,5株同时检测出oprM、mexB基因、有9株仅扩增出oprM基因而没有mexB基因、有3株未扩增出外排基因;oprD2基因缺失共11株,占17.19%。结论调查结果显示,铜绿假单胞菌对亚胺培南的耐药机制主要有金属酶的产生;主动外排的过度表达;孔道蛋白OprD2的缺失。

OBJECTIVE To study the resistant characteristic and the distribution of resistance mechanisms of Pseudomonas aeruginosa to imipenem.METHODS The 150 strains were isolated from our hospital and the minimal inhibitory concentrations（MIC） of 14 antimicrobial agents were detected.Sixty-four strains of imipenem-resistant P.aeruginosa（IRPA） were detected by the disk synergy test,and the resistance gene was analyzed by PCR.RESULTS The resistant rate of IRPA was 42.6%,9 IRPA strains were MBL-producing.4 carried VIM gene and 3 were with IMP gene and others were with the negative result.17 IRPA were with efflux pump,5 strains were with oprM and mexB genes simultaneously;only 9 amplified the oprM gene alone without mexB gene;3 IRPA were not amplitied out the efflux pump gene and 11 IRPA strains had not been able to obtain the oprD2 gene and occupied 17.19%.CONCLUSIONS The important mechanisms of IRPA include：production of MBL over expression of efflux pump and deficiency of porin OprD2.