临床分离肠杆菌科细菌金属β-内酰胺酶检测

摘要

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3297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I MP-8型金属酶的肺炎克雷伯菌，且具有较高的同源性。%Objective To investigate the major genotypes and prevalence of metallo-β-lactamases (MBLs)in En-terobacteriaceae from a hospital in 2007-201 1 . Methods All strains of Enterobacteriaceae were isolated from clini-cal 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 conj u-gation test ,the homology of MBLs-producing strains was detected by pulsed-field gel electrophoresis (PFGE). Results Of 3 297 Enterobacteriaceae isolates ,41 were resistant to carbapenems,and phenotype confirmation test showed 14 strains produced carbapenemase,3 Klebsiellapneumoniae isolates carrying blaIMP-8 belonged to the same clone,which can be transferred to others by plasmid.Conclusion Three blaIMP-8-carrying Klebsiella pneumoniae isolates were found in this hospital,and has a high degree of homology.