产ESBLs大肠埃希菌基因型分析

Genotyping analysis of extended-spectrum β-lactamases (ESBLs) producing Escherichia coli clinically isolated.

目的分析大肠埃希菌临床分离株产超广谱β-内酰胺酶(ESBLs)的主要基因型。方法用表型确定的临床分离产ESBLs的大肠埃希菌47株,分别用TEM、SHV、CTX-M-1、CTX-M-2和CTX-M-9扩增引物进行聚合酶链反应(PCR)扩增,并对PCR产物进行序列分析。结果PCR扩增结果显示TEM、SHV、CTX-M-1、CTX-M-2和CTX-M-9的阳性率分别为59.57%、4.26%、17.02%、19.15%和82.98%,CTX-M型总阳性率为93.62%,序列分析证实扩增为目的产物。结论47株ESBLs大肠埃希菌的主要基因型是CTX-M型和TEM型,且同时携带2种以上基因的菌株占所测菌株的63.83%,需引起临床的高度重视。

Objective To investigate the characteristics of genotype of extended - spectrum β - lactamases（ESBLs） producing clinical isolates of Escherichia coli. Methods The genes of 47 strains of ESBLs producing isolates of Escherichia coli with confirmed phenotype were amplified by PCR using primers specific for TEM, SHV, CTX - M - 1, CTX - M - 2 and CTX - M - 9 respectively and the PCR products were confirmed to be objective products by DNA sequencing. Results The PCR positive rate was 59.57% for TEM, 4.26% for SHV, 17.02% for CTX - M - 1, 19.15% for CTX - M - 2, and 82.98% for CTX - M - 9 respectively. Among them, the CTX- M - type was 93.62% totally. Conclusion CTX - M and TEM were the prevalent genotype of 47 ESBLs producing isolates of Escherichia coli. Among all strains, 63.83 % carry more than 2 ESBLs genes.