非发酵菌的耐药性及产超广谱β-内酰胺酶及碳青霉烯酶分析

Analysis of drug resistance and producing extended spectrum β-lactamase enzymes and carbapenemases of non-fermenting bacteria

目的了解非发酵菌的耐药性及产超广谱β-内酰胺酶(ESBLs)和碳青霉烯酶的情况,以期为临床合理应用抗菌药物提供依据。方法应用VITEK-2全自动微生物分析系统对临床分离非发酵菌进行鉴定。按照美国临床实验室标准化委员会(CLSL/NCCLS 2010版)推荐的纸片扩散法检测156株非发酵菌对常见的15种抗生素耐药情况;按照NCCLS推荐的确认试验(双纸片增效试验)检测菌株产ESBLs情况;采用两种改良Hodge试验进行碳青霉烯酶表型确证。结果临床分离的156株非发酵菌前3位为鲍曼不动杆菌、铜绿假单胞菌、嗜麦芽窄食单胞菌,均呈现高耐药率。鲍曼不动杆菌产ESBLs率为27.6%,铜绿假单胞菌产ESBLs率为37.5%。鲍曼不动杆菌产碳青霉烯酶率为50.0%,铜绿假单胞菌产碳青霉烯酶率为13.3%。两种改良Hodge试验检测鲍曼不动杆菌碳青霉烯酶的一致性较好,检测铜绿假单胞菌碳青霉烯酶的一致性一般,但是无不确定结果。结论非发酵菌耐药率较高,产ESBLs和碳青霉烯酶情况已相当严重,检测碳青霉烯酶阳性的铜绿假单胞菌时,PAE-MHT(以肺炎克雷伯菌ATCC 700603作为指示菌的改良Hodge试验)优于MHT(以大肠埃希菌ATCC 25922作为指示菌的改良Hodge试验)。

Objective To understand the drug resistance rate of non-fermenting bacteria and its production of extended- spectrum β-1actamases （ESBLs） and carbapenemases, in order to provide basis for reasonable application of antimicrobial agents in clinic. Methods VITEK-2 automated microbial analysis system was used to identify non-fermenting bacteria isolated from clinic, the drug resistance of 156 non-fermenting bacteria to 15 kinds of common antibiotics drugs were detected by disk diffusion recommended by American Clinical Laboratory Standards Board （CLSL/NCCLS2010）. NCCLS confirmatory test （double disk efficiency test） was used to detected non-fermenting bacteria producing ESBLs. Two modified Hodge tests were used to confirmed the phenotypic of carbapenemases. Results Among 156 non-fermenting bacteria isolated from clinic, the top three were Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia. They were all showed high drug resistance rates. The producing ESBLs rates of Acinetobacter baumannii and Pseudomonas aeruginusa were 27.6% and 37.5%. The producing earbapenemases rates of Acinetobaeter baumannii and Pseudomonas aeruginosa were 50.0% and 13.3%. Two modified Hodge tests for detection of earbapenemases in Aeinelobacter baumannii had good consistency, which i＋or detection of carbapenemases in Pseudomonas aeruginosa had general consistency, there was no uncertain result. Conclusion Non-fermenting bacteria has high drug resistant rate, the situations of producing ESBLs and carbapenemases are quite serious. For detecting Pseudomonas aeruginosa with positive carbapenemase, PAE-MHT （taken Klebsiella lmeumoniae ATCC 700603 as indicator bacteria in modified Hodge test） is better than MHT Oaken Escheriehia coli ATCC 25922 as indicator bacteria in modified Hodge test）.