临床分离肠杆菌科细菌金属β 内酰胺酶检测

目的研究某院2007-2011年临床分离的肠杆菌科细菌产金属β 内酰胺酶主要基因型及流行情况。方法常规分离菌株，采用纸片扩散法和琼脂稀释法进行药物敏感性试验，改良Hodge试验和Etest MBL确认纸条法表型筛查金属β 内酰胺酶，聚合酶链反应（PCR）扩增金属β 内酰胺酶基因型，接合试验分析质粒携带基因的转移，脉冲场凝胶电泳（PFGE）分析产金属酶细菌的同源性。结果3 297株肠杆菌科细菌中，对碳青霉烯类抗生素耐药的菌株共41株，其中14株碳青霉烯酶表型阳性，3株肺炎克雷伯菌产IMP 8型金属酶，属于同一克隆，并可通过质粒传递。 结论 该院发现3株产IMP 8型金属酶的肺炎克雷伯菌，且具有较高的同源性。

Detection of metallo β lactamases in clinical isolates of Enterobacteriaceae

ObjectiveTo investigate the major genotypes and prevalence of metallo β lactamases (MBLs) in Enterobacteriaceae from a hospital in 2007-2011. MethodsAll strains of Enterobacteriaceae were isolated from clinical specimens by routine method, antimicrobial susceptibility testing was performed by disc diffusion method(Kirby Bauer) and agar dilution method, MBLs was screened by both modified Hodge test and Etest  , MBLs genes were amplified by polymerase chain reaction (PCR), the transference of IMP 8 encoding plasmid was performed by conjugation test , the homology of  MBLs producing strains was detected by pulsed field gel electrophoresis (PFGE). ResultsOf 3 297 Enterobacteriaceae isolates ,41 were   resistant to carbapenems, and phenotype confirmation test showed 14 strains produced carbapenemase, 3 Klebsiella pneumoniae isolates carrying blaIMP 8 belonged to the same clone, which can be transferred to others by plasmid.ConclusionThree blaIMP 8 carrying Klebsiella pneumoniae isolates were found in this hospital，and has a high degree of  homology.