临床分离肠杆菌科细菌金属β-内酰胺酶检测-第三军医大学学报.DOC

临床分离肠杆菌科细菌金属β-内酰胺酶检测 孙秋，黄文祥*，史芳静，刘成伟，李崇智 (重庆医科大学附属第一医院感染科，重庆 400016) 【摘要】目的 研究本院2007-2011年临床分离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，PCR扩增金属β-内酰胺酶基因型，接合实验分析质粒携带IMP-8基因的转移，PFGE鉴定产金属酶细菌类型。 结果 41株肠杆菌科细菌耐碳青霉烯类抗生素，其中14株β-内酰胺酶表型阳性，3株肺炎克雷伯菌产IMP-8型金属酶，属于同一克隆，可通过质粒传递。 结论 IMP-8型金属酶为我院肠杆菌科细菌金属β-内酰胺酶的主要基因型。 【关键词】肠杆菌科细菌，金属β-内酰胺酶，肺炎克雷伯菌 中国图书分类法分类号:R378.2 文献标识码:A Detection of metallo-β-lactamase in clinical isolates of Enterobacteriaceae Sun Qiu , HUANG Wenxiang *,Shi Fangjing , Liu Chengwei and Li Chongzhi (Department of infection disease,the First Affiliated Hospital,Chongqing medical UniverSity,Chongqing 400016,China) [Abstract] Objective To investigate the production and prevalence of metallo-β-lactamase in Enterobacteriaceae from our hospital during 2007-2011. Methods All strains of Enterobacteriaceae were isolated from clinical specimens by routine method．The antimicrobial susceptibility was evaluated by disc diffusion test(Kirby—Bauer)and agar dilution test．The modified Hodge test and Etest MBL test were used to co-detect metallo-β-lactamase. PCR were used to amplify MBLs genes. Conjugation test was used to check the transfer of IMP-8-encoding plasmids. The homology of 3 strains of carrying blaIMP-8 Klebsiella pneumoniae was detected by PFGE. Results A total of 41 carbapenm resistant strains were isolated,and their phenotype confirmation tests showed 14 strains of produces carbapenmase.3 strains of carrying blaIMP-8 Klebsiella pneumoniae belonged to the same clone,which can be transferred to others by plamid. Conclusion The presence of IMP-8 was the main metallo-β-lactamase genes type of Enterobacteriaceae in our hospital. [Key words] Enterobacteriaceae, metallo-β-lactamase, Klebsiella pneumoniae 随着碳青霉烯类抗生素在临床上广泛使用，耐碳青霉烯类抗生素的肠杆菌科菌株（carbapenem-resistant Enterobacteriaceae,CRE）逐渐增加。产β-内酰胺酶是肠杆菌科细菌耐碳青霉烯类抗生素的重要机制，主要以产超广谱β-内酰胺酶（ESBLs）、AmpC酶和金属β-内酰胺酶(metallo-β-lactamase,MBLs)最常见。金属β-内酰胺酶属于Ambler B类（Bush 3组），其催化活性依赖Zn2