耐亚胺培南铜绿假单胞菌的临床分离及耐药机制分析

Clinical distribution and antimicrobial resistance mechanism of Imipenemresistant pseudomonas aeruginosa

目的:了解我院耐亚胺培南铜绿假单胞菌(IRPA)的临床分布情况,并探讨其耐药机制。方法:对2009年1月～2010年12月我院住院患者临床分离的非重复性IRPA的数据资料进行统计分析,采用PCR方法检测金属酶基因和外膜通道蛋白基因。结果:从404株铜绿假单胞菌中共分离出100株IRPA,分离率为24.75%。其中90株(90.0%)IRPA来源于下呼吸道痰液标本;IRPA主要来源于重症医学科(ICU);IRPA对阿米卡星最敏感率为73.0%(耐药率为27.0%),其次是哌拉西林/他唑巴坦(敏感率为63.0%),哌拉西林(敏感率为59.0%),庆大霉素(敏感率为58.0%),头孢他啶(敏感率为57.0%),其余药物的敏感率均<50.0%。仅1株IRPA检测出IMP基因阳性(1.0%),测序为IMP-9型金属酶基因,其余金属酶基因均未检出;oprD2基因缺失的IRPA有65株(65.0%)。结论:我院IRPA主要是由于外膜通道蛋白oprD2缺失引起,且已有IMP-9型IRPA在我院流行,需引起重视。

Objective： To investigate the clinical distribution and antimicrobial resistance mechanism of Imipenem-resistant pseudomonas aeruginosa（IRPA）.Methods： Data on non-recurrent IRPA isolated from inpatients of this hospital from Janaury 2009 to December 2010 were statistically analyzed.β-lactamase gene and the outer membrane channel protein gene were determinated by using PCR method.Results： 404 strains of P.aeruginosa,100 strains were resistant to Imipenem,indicating that IRPA was isolated at a rate of 24.75%.Of these strains,90 strains（90.0%） were primarily isolated from sputum.IRPA originated primarily in ICU.The lowest drug resistance was to Amikacin（27.0%）,followed by Piperacillin/ Tazobactam（63.0%）,Piperacillin（59.0%）,Gentamicin（58.0%）,Ceftazidime（57.0%）,the rates of drug resistance to the other antibiotics were less than 50.0%.Only one strain of IRPA was detected positive by IMP gene（1.0%）,and sequencing result showed it was a IMP-9 type metallo-β-lactamases（MBL） gene,while other MBL genes were not detected.The absent rate of oprD2 gene was 65.0%.Conclusion： The loss of oprD2 gene plays an important role in antimicrobial resistance mechanism of pseudomonas aeruginosa to Imipenem.Also,the IMP-9 type MBL is prevalent in our hospital,it should be enhanced to monitor and control IRPA.