多重PCR检测临床产ESBLs大肠埃希菌的耐药基因型研究

目的了解产超广谱β-内酰胺酶(ESBLs)大肠埃希菌的耐药性、产ESBLs的阳性率及耐药基因之间的关系。方法采用Kirby-Bauer(K-B)琼脂扩散法检测120株临床分离的大肠埃希菌对18种抗生素的耐药性,用酶抑制剂增强实验纸片法检测产ESBLs菌株,运用多重PCR技术检测相关耐药基因,用DNA序列分析确认基因亚型。结果120株大肠埃希菌产ESBLs的有51株,阳性率为42.5%。120株大肠埃希菌对亚胺培南全部敏感,产ESBLs的大肠埃希菌对头孢唑啉、头孢噻肟、头孢曲松、头孢哌酮、头孢他啶等头孢类抗菌药物的耐药率高达100%;51株产ESBLs菌株其中46株扩增到CTX-M型耐药基因,44株扩增到TEM型基因,2株扩增到SHV基因,1株OXA型基因,未检出PER和VEB型。结论大肠埃希菌产ESBLs较高,耐药显著,碳青酶烯类抗生素是目前治疗产ESBLs大肠埃希菌最有效的药物;产ESBLs大肠埃希菌的主要基因型别为CTX-M型和TEM型。

Multiplex PCR assay for genotype of ESBLs -producing Escherichia coil in clinical isolates

Objective To investigate the production of extended-spectrum β-lactamases(ESBLs) of the drug resistance of Escherichia coli producing ESBLs positive rate and the relationship with the resistance gene.Methods The K-B agar diffusion assay the resistance of 120 clinical isolates of Escherichia coli to the 18 kinds of antibiotics,using enzyme inhibitors enhance paper to test phenotype of ESBLs,using multiplex PCR to detect related resistance gene,and using DNA sequence analysis to confirmed the gene subtypes.Results 51 of 120 Escherichia coli producing ESBLs,the positive rate was 42.5%.All of 120 isolates are sensitive to imipenem,the antimicrobial resistance rate of ESBLs-producing isolats to cefazolin,cefotaxime,ceftriaxone,cefoperazone,ceftazidime and other cephalosporins was as high as 100%;51 strains producing ESBLs which amplified 46 to CTX-M-type resistance gene,amplified by 44 to TEM-type genes,two amplified SHV genes and one OXA-type genes.PER-type and VEB-type were negative.Conclusion Carbapenem antibiotics is currently the most effective drugs to treatment Escherichia coli which producing ESBLs;the major genotypes were CTX-M-type and TEM-type.