产超广谱β-内酰胺酶大肠埃希菌耐药表型和基因型分析  

Study on the antimicrobial resistance and genotypes of extended-spectrum β-lactamases in Escherichia coli isolates

作　　者：吴祥林[1] 沈继龙[2] 徐元宏[1] 

机构地区：[1]安徽医科大学临床检验诊断学教研室 [2]安徽医科大学医学检验系,安徽合肥230032

出　　处：《蚌埠医学院学报》2008年第5期605-608,共4页Journal of Bengbu Medical College

摘　　要：目的:分析临床分离大肠埃希菌耐药性、产超广谱β-内酰胺酶(ESBLs)阳性率及耐药基因之间的关系。方法:用K-B法检测117株大肠埃希菌耐药性,用酶抑制剂增强实验纸片法检测产ESBLs菌株,用PCR法检测相关耐药基因,用DNA序列分析确认基因亚型。结果:117株大肠埃希菌产ESBLs 49株,阳性率41.9%。产ESBLs菌株对青霉素类和第一、第二代头孢菌素耐药率100%,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>95%,对酶抑制剂哌拉西林/三唑巴坦和头孢哌酮/舒巴坦耐药率<20%,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。49株产ESBLs菌株PCR均扩增到CTX-M型耐药基因,44株扩增到TEM型基因,未扩增到其他基因型。DNA序列分析证实为CTX-M-14亚型、CTX-M-3亚型和广谱酶TEM-1亚型基因。结论:大肠埃希菌产ESBLs较高,耐药显著;耐药基因以CTX-M-14亚型为主,其次为CTX-M-3亚型,尚未检出其他ESBLs基因。TEM-1亚型广谱内酰胺酶基因在大肠埃希菌中普遍存在。Objective：To study the relationship between antibiotic resistance and extended-spectrum β-lactamases（ESBLs） genes in clinical isolates of E. coli. Methods：Antibiotic susceptibility was tested by Kirby-Bauer disk diffusion method and ESBLs production was detected by CLSI phenotypic confirmatory test in E. coli isolates. The β-1aetamases genes were identified by PCR and sequencing. Results：Fourty-nine of 117 strains collected were ESBLs-producing E. coli and all of them were resistant to ampicillin, piperacillin, cefazolin,cefuroxime. The resistance rates to cefotaxime, ceftriaxone, eefpodoxime, and cefoperazone were more than 95%, but only 41.8% to eeftazidime. The resistance rates to piperacillin-tazohactam and cefoperazone-sulbactam were 8. 1% and 18. 4%, respectively,to imipenem was 0.0%. ESBLs gene was found in all ESBLs-produeing isolates, and CTX-M-14 genotype was dominated （87.8%）. Conclusions：ESBLs-producing E. coli are prevelance in our hospital and most of them are multidrug resistant strains. CTX- M-14 is the main genotype of ESBLs,and the second is CTX-M-3 genotype. No other genotype of ESBLs was detected.

关 键 词：大肠埃希菌 超广谱Β-内酰胺酶 耐药性 基因型 

分 类 号：R378.21[医药卫生—病原生物学]