产ESBLs与AmpC酶肠杆菌科细菌表型检测及基因型分析

Phenotypic detection and genotyping analysis of Enterobacteriaceae bacteria producing ESBLs and AmpC β-lactamase

目的了解肠杆菌科细菌产超广谱β-内酰胺酶(ESBLs)与Amp C酶基因型特征。方法对临床分离的287株大肠埃希菌和肺炎克雷伯菌筛选产ESBLs/AmpC酶的菌株进行表型确证试验。对常见的SHV、TEM超广谱β-内酰胺酶基因型和DHA-1、ACT-1 AmpC酶基因型进行PCR扩增,并对PCR产物进行琼脂糖凝胶电泳分析。结果表型确证产酶大肠埃希菌SHV、TEM、DHA-1、ACT-1基因的阳性率分别为46.5%、49.5%、50.9%、32.1%,产酶肺炎克雷伯菌SHV、TEM、DHA-1、ACT-1基因的阳性率分别为50.0%、26.7%、62.5%、45.8%。部分分离菌株同时携带2种或以上基因型。结论临床分离的产ESBLs与AmpC酶大肠埃希菌及肺炎克雷伯菌携带多种耐药基因比率较高,临床检出多重耐药细菌逐年升高,临床对产酶的多重耐药菌的防治迫在眉睫。

Objective To investigate the genotypic character of Enterobacteriaceae bacteria producing extended spectrum β-lactamases（ ESBLs） and Amp C β-lactamase. Methods 287 screened strains of Escherichia coli and Klebsiella pneumoniae suspected to produce ESBLs / AmpC were conducted for phenotypic confirmation test. The SHV,TEM in ESBLs-producing isolates and the DHA-1 and ACT-1 AmpC isolates were amplified by PCR and the results were analyzed by agarose gel electrophoresis. Results Phenotypic confirmation test showed that the positive rates of SHV,TEM,DHA-1 and ACT-1 genes were respectively 46. 5%,49. 5%,50. 9%,32. 1% in all the Escherichia coli producing enzyme,and that were respectively50. 0%,26. 7%,62. 5%,45. 8% in all the Klebsiella pneumoniae producing enzyme. Some strains carried more than 2 genotypes. Conclusion The carrying rate of resistance genes of Escherichia coli and Klebsiella pneumoniae producing ESBLs and Amp C β-lactamases is high. The detected multi drug resistant bacteria in clinic increased year by year,and the clinical treatment of the resistant bacteria producing enzyme is extremely urgent.