耐亚胺培南铜绿假单胞菌金属β-内酰胺酶和oprD2基因的检测

摘要

AIM: To investigate the molecular epidemiology of metallo - β - lactamases gene and oprD2 gene in imipenem - resistant Pseudomonas aeruginosa ( IRPA ) isolated from The First Municipal People's Hospital of Guangzhou.METHODS: Biomerieux VITEK - 2 system was used to identify Pseudomonas aeruginosa and its drug susceptibility.The metallo - β - lactamase of imipenem - resistant Pseudomonas aeruginosa was measured by double disk synergy test.The metallo - β - lactamase gene and oprD2 gene in imipenem - resistant Pseudomonas aeruginosa were detected by polymerase chain reaction ( PCR ).RESULTS: The resistance rate of clinically - isolated 157 strains of imipenem - resistant Pseudomonas aeruginosa to the common antimicrobial agents was higher than 40％ , in which 20 ( 12.7％ ) were MBL -positive and 13 were IMP gene positive.The deletion of oprD2 gene was not found in 90 strains ( 57.3％ ).No VIM gene was observed.IMP gene positive with oprD2 gene deletion was found in 10 strains of imipenem - resistant Pseudomonas aeruginosa.CONCLUSION: IMP is the most prevalent MBL genotype in our hospital.The strains with IMP gene positive and oprD2 gene deletion are important characteristics of IRPA.%目的:了解我院临床分离下呼吸道感染的耐亚胺培南铜绿假单胞菌(IRPA) oprD2基因和金属β-内酰胺酶(MBL)的分子流行病学情况.方法:铜绿假单胞菌的鉴定和药敏采用VITEK-2系统进行药物的最低抑菌浓度(MIC)检测.应用双纸片增效法和聚合酶链反应(PCR)方法检测其产MBL的表型及相关的oprD2基因、IMP型和VIM型金属酶基因.结果:157株亚胺培南铜绿假单胞菌对多种抗菌药物的耐药率均在40%以上,经双纸片增效法筛选出20株MBL阳性(12.7%),经PCR方法检测20株MBL阳性株中有13株IMP型基因阳性,oprD2基因有67株阳性,其余90株缺失(57.3%),未发现VIM型基因.有10株IRPA既携带IMP型基因同时又有oprD2基因缺失.结论:我院临床分离下呼吸道感染的耐亚胺培南铜绿假单胞菌呈较严重的多重耐药.IMP型基因是我院IRPA产MBL的主要基因型;oprD2基因缺失可能是铜绿假单胞菌亚胺培南耐药的重要原因之一.