【摘要】 目的了解河南地区大肠埃希菌中质粒AmpC酶的流行分布及其基因特征。方法对380株大肠埃希菌进行AmpC酶表型筛选,对筛选阳性株进行多重聚合酶链反应(PCR)及型特异PCR、克隆、测序;等电聚焦电泳检测细菌β-内酰胺酶等电点;接合实验验证质粒传递性;肠杆菌科基因组内重复一致序列(ERIC-2)PCR检测同源性。结果380株大肠埃希菌中2.1%(8株)的细菌产AmpC酶,经测序证实均为DHA-1型质粒AmpC酶基因,ERIC-2 PCR结果显示质粒AmpC酶主要以非克隆传播为主。结论河南地区发现DHA-1型质粒AmpC酶以非克隆传播为主。更多还原

【Abstract】 Objective To investigate the genotype and distribution of plasmid-mediated AmpC β-lactamases in Escherichia coli in Henan. Methods 380 Escherichia coli were detected by standard disc diffusion method which was used as screen test for AmpC β-lactamase.Multiplex polymerase chain reaction(PCR),type-specific PCR,clone,sequencing,isoelectric focusing analysis,conjugation and enterobacterial repetitive intergenic consensus-2(ERIC-2) PCR were performed on positive strains to determine the genotype,the isoelectric point,the transitivity of plasmid and the homology of AmpC β-lactamases.Results 8 of 380 Escherichia coli strains(2.1%) were AmpC β-lactamases-positive strains.All of them were bla_DHA which were confirmed by sequencing.The results of ERIC-2 PCR analysis indicated that the prevalences of plasmid-mediated AmpC β-lactamase were not due to epidemic strains.Conclusions The clinical isolate of Escherichia coli producing DHA-1 type plasmid-mediated AmpC β-lactamase was found in Henan.The prevalence were not due to epidemic strains.更多还原