超广谱β内酰胺酶分子流行病学研究

Molecular epidemiologic study of extended-spectrum beta-lactamase in escherichia coli and Klebsiella pnenmoniae

目的 了解杭州市 2 0 0 0～ 2 0 0 1年产超广谱 β内酰胺酶 (ESBLs)大肠埃希菌和肺炎克雷伯菌的分离率和各基因型的流行情况。方法 收集本市 5家医院大肠埃希菌和肺炎克雷伯菌共 198株 ,采用酶抑制剂增强纸片扩散法检出产ESBLs菌并测定对头孢噻肟、头孢他啶的最低抑菌浓度 ;等电点测定及PCR扩增对产ESBLs初步分型 ;PCR扩增阳性产物测序 ,序列分析进一步明确基因型。结果 杭州市大肠埃希菌和肺炎克雷伯菌的ESBLs分离率为 2 5 .76 % ,SHV型、TEM型、CTX M型分别占产ESBLs菌的 17.6 5 %、84 .31%和 80 .6 5 %。基因型分布为 :SHV 11、12 ,TEM 1,CTX M 3、13、14及CTX M 3 like型。结论 CTX M型ESBLs是本市产ESBLs大肠埃希菌和肺炎克雷伯菌中最主要基因型。

Objective To investigate the prevalence of the genotypes of extended spectrum β lactamses (ESBLs) in klebsiella pneumoniae and eschrichia coli, which were isolated in Hangzhou City from 2000 to 2001. Methods Total of 198 isolates of E. coil and K. pneumoniae were isolated from five hospitals in Hangzhou. ESBLs-producing isolates were detected by inhibitor-potentiated disc diffusion test, Agar dilution method was used to determine the minimum inhibitory concentrations (MIC) of cefotaxime and ceftazidime.ESBLs genes were analysed by isoelectric focusing (IEF) assay and PCR initially,genotypes were determined by sequencing. Results 51 isolates (25.76%) from 198 E. coil and K. pneumoniae strains were obtained. In ESBLs producers, the ESBLs types of SHV, TEM, CTX-M were 17.65%,84.31% and 80.39% respectively. genotypes were: SHV 11,12;TEM 1;CTX M 3and CTX M 3 like, CTX M 13,14. respectively. Conclusions CTX M type were the major genotypes of ESBLs in klebsiella pneumoniae and eschrichia coli isolated in Hangzhou city.