大肠埃希菌表型及耐药趋势分析

Analysis of phenotype and drug resistance of Escherichia coli

目的了解临床分离的大肠埃希菌的分布情况、表型特征及耐药趋势。方法收集2008年1月至2010年12月临床分离的大肠埃希菌,用VITEK 2 Compact对其进行鉴定和17种常用抗菌药物的药物敏感性试验;高级专家系统软件(AESTM)筛选表型。结果 3 a间临床共分离到1 523株大肠埃希菌,主要来自洁净中段尿标本(677株,44.5%)和呼吸道标本(354株,23.2%)。其表型主要分为产超广谱β-内酰胺酶(ESBLs)株、产获得性青霉素酶株和野生株。其中2008、2009和2010年产ESBLs的总株数分别为238(58.33%)、287(58.93%)和398株(63.38%);产获得性青霉素酶总株数分别为118(28.92%)、144(29.57%)和128株(20.38%);野生株总数分别为49(12.01%)、53(10.88%)和95株(15.13%)。3 a间大肠埃希菌对氨苄西林和复方新诺明的耐药率逐年上升(P<0.05);产ES-BLs株对环丙沙星、头孢曲松、庆大霉素、左旋氧氟沙星和氨苄西林/舒巴坦的耐药率逐年降低(P<0.05)。结论大肠埃希菌产酶率高,存在多种耐药表型,其中以产ESBLs株最为常见;产酶株的多重耐药和交叉耐药严重,应高度重视对产酶株的监控,合理应用抗生素,以控制耐药株的产生和扩散。

Objective To explore the distribution,phenotypes and resistance profile of Escherichia coli in clinical isolates.Methods The Escherichia coli of clinical isolates from January 2008 to December 2010 were collected.VITEK 2 Compact was used to identify the Escherichia coli and detected it′s drug sensitivity in vitro.Then phenotypes were determined by AESTM（advanced expert system） of VITEK 2 Compact.Results A total of 1 523 Escherichia coli were isolated in three years,mainly from the clean midstream specimen of urine（677,44.5%） and respiratory tract（354,23.2%）.The main phenotypes of Escherichia coli were extended-spectrum beta-lactamase（ESBLs） strains,acquired penicillinase producing strains and wild strains.The total number of ESBLs strains were 238（58.33%）,287（58.93%）and 398（63.38%）in 2008,2009 and 2010 year respectively;the acquired penicillinase producing strains of the three years were 118（28.92%）,144（29.57%） and 128（20.38%）respectively;the wild strains accounted of the three years were 49（12.01%）,53（10.88%）and 95（15.13%）respectively.The resistance rates of Escherichia coli to ampicillin and cotrimoxazole in three years were increasing year by year（P〈0.05）;the resistance rates of ESBLs producing strains to ciprofloxacin,ceftriaxone,gentamicin,levofloxacin and ampicillin / sulbactam were decreasing year by year（P〈0.05）.Conclusion The enzyme production rate of Escherichia coli is very high,and there is a variety of resistant phenotypes,of which the producing ESBLs strains are the most common.The multiple drug resistance and cross-resistance is very serious of production enzyme strains and should be pay more attention to the monitoring of production enzyme strains,and rational use of antibiotics to control the emergence and spread of resistant strains.