73株大肠埃希菌耐药表型分析

目的分析临床分离的大肠埃希菌的耐药性、产超广谱β-内酰胺酶（ESBLs）阳性率及耐药性之间的关系。方法用微量肉汤稀释法检测2009年10月至2010年3月分离的73株大肠埃希菌的耐药性,用酶抑制剂增强实验纸片法检测产ESBLs菌株。结果 73株大肠埃希菌产ESBLs20株,阳性率为27.4%。产ESBLs菌株对青霉素类和第一、第二代头孢菌素耐药率〉95%,对第三代头孢菌素中头孢哌酮、头孢噻肟和头孢曲松耐药率均为95%,但头孢他定耐药率为20%。对酶抑制剂哌拉西林/三唑巴坦、替卡西林/克拉维酸和头孢哌酮/舒巴坦的耐药率〈30%,耐药率低于30%的还有头孢西丁、阿米卡星,未检测到亚胺培南耐药株。非产ESBLs菌株耐药率明显低于产ESBLs菌株。结论本医院分离的产ESBLs大肠埃希菌的比例低于国内其他地区,具有显著的耐药性。

Resistance phenotype analysis of 73 isolates of Escherichia coli

Objective To investigate the resistance phenotype of extended-spectrum 3-1actamases （ESBLs） in Escherichia coli isolates. Method Antibiotic susceptibility was determined by micro broth dilution method and ESBLs producers were detected by CLSI Phenotypic Confirmatory Test in 73 isolates of E.coli. Results 20 of 73 strains collected were found to be ESBLs-produeing E.coli.The resistance rate of ESBLs-produeing E.coli to Ampicillin,Cefazolin was 100% ,to Piperacillin, Cefotaxime, Ceftriaxone and Cefoperazone were all 95%, but to Ceftazidime was only 20%. The resistance rates to Piperacillin- tazobactam, Cefoperazone-sulbactam Cefoxitin and Amikacin were lower than 30%.These ESBLs producing E.coli isolates show no resistance to Imipenem.The resistance rates of non-producing E.coli were lower than ESBLs producers. Conclusion The percentage of ESBLs-producing E.coli isolates among all of the analyzed isolates is lower than in the reports from the other districts of China and most of them are multidrug resistant strains.