大连地区耐亚胺培南铜绿假单胞菌金属β-内酰胺酶检测及耐药性分析

Detection of Metallo-β-lactamase gene and antibiotics resistance of Imipenem-resistant Pseudomonas aeruginosain Dalian area

目的了解大连地区分离的耐亚胺培南铜绿假单胞菌的耐药特征,金属β-内酰胺酶携带情况,提供大连地区院内控制铜绿假单胞菌感染的依据。方法选取2013年1月至2014年9月临床分离的400株铜绿假单胞菌,进行菌种鉴定和药物敏感试验;金属酶检测采用E-test试验;PCR法扩增产金属β-内酰胺酶的基因,并对扩增阳性产物进行测序确认。结果 400株铜绿假单胞菌的标本以呼吸道分泌物最多,占81.5%;分布以呼吸内科和ICU病房最高,占总数的19.8%和25.5%;药敏结果发现有89株铜绿假单胞菌对亚胺培南耐药,且多数为多重耐药菌株;400株铜绿假单胞菌经E-test试验进行金属酶表型筛查,有17株金属酶阳性,检出率为19.1%;经PCR扩增金属酶基因阳性的有11株,其中8株为IMP-1,3株为VIM-2,其他几种基因均未检出。结论大连地区耐亚胺培南的89株铜绿假单胞菌多数是多重耐药菌株;产金属β-内酰胺酶在大连地区铜绿假单胞菌对亚胺培南耐药中发挥重要作用,酶的基因型主要为IMP-1和VIM-2。

Objective To investigate the drug resistance of Carbapenem-resistant Pseudomonas aeruginosa（PA）in Dalian area,and provide reference for the prevention and control of nosocomial infections.Methods 400 clinical isolates of Pseudomonas aeruginosa were collected from four tertiary hospitals in Dalian during January 2013 to September 2014;Identification of isolates and antimicrobial susceptibility testing were performed.E-test（IPM/EDTA）method was used to detect MBL phenotype;PCR was applied to detect MBL genes（IMP-K,IMP-2,VIM-1,VIM-2,GIM,SPM,SIM and NDM）.Results The 400 Pseudomonas aeruginosa were mainly isolated from respiratory tract secretion,accounting for 81.5%,most of which were from respiratory department（19.8%）and ICU ward（25.5%）.89 strains were resistant to Imipenem and most of them were multidrug-resistant.17 strains of Imipenem-resistant isolates were MBL positive,accounting for 19.1%（17/89）,while most of Imipenem sensitive strains were MBL negative.PCR amplification showed that 11 strains of Imipenem-resistant isolates carried MBL genes,among which 8strains carried IMP-1gene and 3strains carried VIM-2gene.IMP-2,VIM-1,GIM,SPM,SIM and NDM genes were not found.Conclusion The Imipenem-resistant PA in Dalian area are often multidrug resistant;The genes producing metallo-β-lactamase and metallo-β-lactamase are one of the main mechanisms of drug resistance of Pseudomonas aeruginosa to Imipenem,and the main genotypes are IMP-1and VIM-2.