大肠埃希菌超广谱β-内酰胺酶基因型及耐药性研究

 目的 了解沈阳地区产超广谱β-内酰胺酶(ESBLs)大肠埃希菌的流行和耐药特点,初步确定产ESBLs大肠埃希菌的基闪型.方法 收集沈阳地区大肠埃希菌临床分离株246株,通过CLSI确认试验确认产ESBLs大肠埃希菌,应用K-B纸片法进行药敏试验,采用PCR方法检测ESBLs的基冈型.结果 产ESBLs大肠埃希菌共127株(51.6%),对头孢噻肟、头孢曲松、氨曲南、头孢他啶、头孢两丁及阿莫西林/克拉维酸的耐药率分别是:68.3%、92%、43.1%、24.4%、10.5%及37.4%,亚胺培南和美洛培南的敏感率均为100%;在72株CTX-M型中53株(60.2%)为CTX-M-9型、15株(17%)为CTX-M-1型,4株(4.6%)同时携带了CTX-M-9及CTX-M-1两种基因.结论 产ESBLs大肠埃希菌具有多重耐药的特点,产ES-BLs的大肠埃希菌大都携带CTX-M型ESBLs基因.

Resistance and genotype of ESBLs-producing Escherichia coli

Objective To investigate the rate and the resistance of extended spectrumβ-lactamases(ESBLs) - producing Escherichia coli,and to identify the genotype of ESBL sproducing isolates.Methods E.coli in clinical isolates were collected from Shenyang region.After the identification of ESBLs - producing E.coli were determined by double-disk synergy test,18 antibiotics susceptibility was detected by Kirby-Bauer disc diffusion.The genotype of ESBLs were characterized by polymerase chain reaction (PCR) and sequencing.Results 127 strains(51.6%) were ESBL - s producing isolates.Most of ESBLs producing isolates shows resistance against penicillins,aztreonam and the third generation cephalosporins,with cefotaxime 68.3%,ceftriaxone 92.0%,aztreonam 43.1%,cefoxitin 10.5%,ceftazidime 24.4%,and amoxicillin/clavulanic acid 37.4%,respectively.All ESBLs - producers were 100%susceptible to carbepenems.Of 72 isolates,53 strains harbored CTXM9 groups,15 strains were with CTXM1 groups,and 4 strains produced CTX-M9 groups and CTXM1 groups simultaneously.Conclusions The ESBLsproducing isolates are multiresistant. Most of the ESBL - s producing E.coli carries CTXM types.