用CLSI和EUCAST两种标准判定产ESBLs菌株药敏结果的差异  

Differences in the antimicrobial susceptibility of bacteria producing extendedspectrumβ-lactamases judged based on the CLSI and the EUCAST standards

作　　者：邵海枫[1] 潘红[1] 王卫萍[1] 黄梅[1] 范明[1] 尤金炜[1] 王颖[1] 

机构地区：[1]南京军区南京总医院临床中心实验科微生物室,南京210002

出　　处：《临床检验杂志》2009年第6期437-439,共3页Chinese Journal of Clinical Laboratory Science

基　　金：南京军区医药卫生"十五"重点课题(07M089)

摘　　要：目的分析美国CLSI标准和欧洲EUCAST标准判读产超广谱β-内酰胺酶(ESBLs)的大肠埃希菌(E.coli)和肺炎克雷伯菌(K.pneumoniae)对4种常用广谱头孢菌素药敏结果的差异。方法收集按CLSI标准因产ESBLs而将广谱头孢菌素药敏结果由敏感或中介改为耐药的E coli和K.pneumoniae,用琼脂稀释法检测最低抑菌浓度(MIC),用CLSI标准和EUCAST标准进行敏感性界定。同时用PCR及Hodge-test检测4种ESBLs基因和高活性β-内酰胺酶。结果55株菌中53株扩增出介导ESBLs的相关基因,Hodge-test显示55株菌均产高活性β-内酰胺酶;用EUCAST标准界定,55株菌株对头孢三嗪和头孢噻肟均耐药,对头孢他啶和头孢吡肟敏感的菌株分别有5和7株。结论在目前的耐药现状中,用CLSI规则和用EUCAST折点判读E.coli和K.pneumoniae对4种常用第三代和第四代头孢菌素敏感性,对临床治疗结果进行预测的差异主要出现在产ESBLs且头孢他啶和头孢吡肟MICs值≤1μg/m1的菌株中。Objective To analyze the differences of antimicrobial susceptibility of four commonly used cephalosporins in the antimicrobial susceptibility tests for bacteria producing extended-spectrum β-1actamases judged based on the CLSI and the EUCAT standards. Methods Based on CLSI standard in which sensitive or intermediate bacteria are altered to resistant when the bacteria produce ES- BLs, ESBL-producing E. coli and K. pneumoniae were collected. Minimum inhibitory concentration （MIC） was determined by the agar dilution method, and the sensitivity of bacterial isolates was defined based on the CLIS and the EUCAS standards. In addition, PCR and Hodge-test were used to detect four-type genes encoding ESBLs and high β-1actamase activity respectively. Results Fifty-three of the 55 isolates carried genes encoding ESBLs ,but Hodge-test showed that all 55 isolates produced high β-lactamase activity. Based on the EUCAST standard, all 55 isolates were resistant to ceftriaxone and cefotaxime,5 were sensitive to ceftazidime, and 7 were sensitive to cefepime, respectively. Conclusions In the current antimicrobial resistance, based on the CLST rule and the EUCAST break point, the susceptibility difference of E. coli and K. pneumoniae to the commonly used four third and fourth generation cephalosporins occurs mainly in the isolates that produce ESBLs at the MICs of CAZ or CFP≤1μg/ml.

关 键 词：ESBLS 药敏 大肠埃希茵 肺炎克雷伯菌 

分 类 号：R446.5[医药卫生—诊断学]