耐碳青霉烯类铜绿假单胞菌金属酶的筛选及分型研究

Screening and genotyping of metallo-β-lactamase in carbapenems-resistant Pseudomonas aeruginosa

目的了解我院耐碳青霉烯类抗生素铜绿假单胞菌的金属酶(MBL)携带情况及型别特点,并探讨进行金属酶筛选的简便方法。方法采用K-B法进行药物敏感性试验,采用2-巯基乙醇纸片与EDTA纸片协同试验筛选产MBL菌株,并对MBL基因进行PCR和序列分析。结果45株碳青霉烯类抗生素耐药菌株用2-巯基乙醇纸片协同试验阳性3株,EDTA纸片协同试验阳性4株,经PCR验证均为阳性,除此之外,还有1株PCR阳性而2种纸片协同法都没有筛选出来。其中2-巯基乙醇纸片协同试验筛选的灵敏度为60%,特异度为95%,准确率为95%,EDTA纸片协同试验的灵敏度为80%,特异度为97%,准确率为97%。引物IMP扩增阳性4株,VIM扩增阳性1株,PCR产物纯化测序后发现IMP均为IMP-1型而VIM为VIM-2型。结论用EDTA协同试验法对碳青霉烯类抗生素耐药铜绿假单胞菌进行MBL的筛选简单有效,可用来在临床微生物实验室作为产MBL铜绿假单胞菌的初筛试验。分型研究表明我院流行的铜绿假单胞菌以产IMP-1型为主。

Objective To study the metallo-β-lactamases in carbapenems-resistant P.aeruginosa and its genotypes and test a convenient method to screen the metallo-β-lactamase.MethodsAntimicrobial susceptibility testing was conducted with Kirby-Bauer method.The 2-mercaptoethanol disc and EDTA disc were used to screen metallo-β-lactamase-positive strains from carbapenems-resistant P.aeruginosa.Metallo-β-lactamase genes were amplified and sequenced.ResultsThree strains of P.aeruginosa were positive to produce metallo-β-la...