鲍曼不动杆菌ESBLs和金属酶的基因型分析

Genotyping of extended-spectrum β-lactamases and metallo-β-lactamases in Acinetobacter baumannii

目的了解天津地区鲍曼不动杆菌中超广谱β-内酰胺酶和金属酶基因的分布情况。方法对天津地区6所三级甲等医院临床分离的72株鲍曼不动杆菌,以K-B法进行抗生素敏感试验;用双纸片增效法对亚胺培南耐药菌株进行金属酶表型筛选,并以PCR方法检测IMP-1、IMP-2、VIM2型金属酶基因;用三维试验对第三代头孢菌株进行ESBLs表型初筛,并以PCR方法检测ESBLs基因。结果8株(8/72)耐药亚胺培南鲍曼不动杆菌中,4株金属酶表型阳性。以PCR方法检测,1株IMP-1阳性,3株出现IMP 1+IMP-2+VIM-2型金属酶基因同时阳性;30株(30/72)耐第三代头孢鲍曼不动杆菌中,11株产TEM型ESBLs,4株产PER型ESBLs,1株产VEB 1型ESBLs。结论天津地区鲍曼不动杆菌主要以携带TEM型ESBLs为主,在耐亚胺培南鲍曼不动杆菌中发现IMP-1、IMP-2和VIM-2型金属酶,并且VEB-1型ESBLs和VIM-2型金属酶为天津地区首次报道。

Objective To study the gene distribution of extended spectrum β-lactamases （ESBLs） and metallo-β-lactamases （MBLs） in Aeinetobacter baumannii in Tianjin area. Methods Totally 72 strains of Aeinetobaeter baumannii were isolated from six hospitals with the level Ⅲ of first-class in Tianjin area. Antimierobial susceptibility testing was performed by the Kirby-Bauer disk diffusion method; MBL phenotype screening was performed by double disc enhancing test for imipenem-resistance Acinetobacter baumannii; IMP-1,IMP-2,VIM-2 genes were detected by PCR; ESBLs phenotype screening was performed by three-dimensional test for the third cephalosporin-resistant Acinetobacter baumannii; ESBLs genes were detected by PCR. Results Four isolates were MBL positive out of 8 strain of imipenem-resistant Acinetobacter baumannii; PCR assay showed 1 isolate expressed IMP-1 gene,and 3 isolates were PCR positive for IMP-1,IMP 2 and VIM-2 MBL. In 30 strains of the third cephalosporin resistant Aeinetobacter baumannii,11 isolates expressed TEM gene,4 isolates expressed PER gene,and 1 strain expressed VEB-1 gene. Conclusion In genotyping of ESBLs in Aeinetobacter baumannii,TEM-type is predominant in Tianjin area. IMP-1, IMP-2 and VIM-2 MBL were found in imipenem-resistant Acinetobacter baumannii isolates; furthermore, VEB-1 ESBLs and VIM-2 MBL were firstly reported in Tianjin area.