泌尿系感染23株大肠埃希菌ERIC—PCR多态性及耐药性分析

目的了解泌尿系统感染大肠埃希菌菌株变异情况及产超广谱p内酰胺酶的耐药情况，指导临床合理用药。方法药敏试验采用K—B法和NCCLS推荐的双纸片协同试验进行超广谱β-内酰胺酶（ESBLs）的检测；23株大肠埃希菌运用ERIC—PCR进行聚类分析，并用聚类统计学软件进行同源性分析。结果23株大肠埃希菌中，检出产ESBLs＋11株，检出率为47.8％；药敏结果显示ESBLs＋菌对20种抗菌药物的耐药率均显著高于ESBLs-菌；聚类分析，将23株大肠埃希菌主要分为四大类，相似系数从0．56～0．92。结论ESBLs＋的大肠埃希菌对头孢噻肟的水解能力很强，大部分ESBLs＋菌株对头孢他啶较稳定；亚胺培南、关洛培南是目前少数对ESBLs＋菌高度稳定的抗生素；应加大对第三代头孢菌素应用的监督，减轻抗生素的选择压力；ERIC—PCR指纹图谱基因技术分型方法分辨率高，重复性好，简便快捷，可用于大肠埃希菌医院感染流行病学监测。

ERIC-PCR Polymorphism and Drug-susceptibility Analysis of 23 Strains of E. coli from Infected Urinary Tract

Objective To understand polymorphism of E. coli from infected urinary tract and drug-susceptibility of E. coli strains with extended spectrum beta-lactamases （ESBLs）,which provide rational usage guide of drug for the hospital. Methods Strains were screened from the infected urinary tract,the antibiotic sensitivity to determinate by K-B slip resistance,the ESBLs determined by disc-paper diffusion methods recommended by NCCLS,polymorphism analysized by EIEC- PCR,the similarity between strains clustered by the statistical software. Results 11 strains were identified as ESBLs＋ among the 23 strains of E. coli,the positive percentage was 47.8% ,and the drug susceptibility results showed that ESBLs＋ strains had higher resistance to 20 drugs than ESBLs- strains. The clustering from EIEC-PCR profiles displaied that the strains were mainly divided into four subtypes,similarity coefficients were 0. 56-0. 92, Conclusion The dominant ESBLs ＋ strains were resistant to the cefotaxime, the most ESBLs ＋ strains were sensitive to ceftazidime. Imipenem and Meropenem,widely and effectively applied in the clinic ,are susceptible to the ESBLs＋ strains. ERIC-PCR is one of powerful methods to differentiate and subtype the strains ,with high resolution,good reproducibility and simple and rapid characteristics,can be widespread used in the Epidemiological Surveillance of hospital.