大肠埃希菌质粒介导AmpC酶基因检测及耐药性分析

摘要

Objective To understand the genotype distribution and antibiotic resistance of Escherichia coli isolates producing plasmid-mediated AmpC β-1actamase in Shenzhen People's Hospital. Methods 110 cefoxitinresistant Escherichia coli clinical strains were collected, The plasmid of the strains were extracted, and the AmpC gene were detected by using multiplex PCR. DNA sequencing was carried out for AmpC genotyping. Antibiotic susceptibility of the isolates was determined by the Kirby-Bauer methods. Results In all these Escherichia coli isolates, 13 were detected carrying AmpC gene. 12 of them were DHA-1, one was CMY-2. AmpC-positive strains showed 100％ susceptible to imipenem and meropenem, They had a lower susceptibility to the other antibiotics.Conclusions DHA-1 was the major genotype of plasmid-mediated AmpC β-lactamase in Escherichia coli isolates from Shenzhen People's Hospital, the strains showed strong resistance to a variety of antibiotics.%目的 了解深圳市人民医院质粒介导AmpC酶大肠埃希菌的基因型特点和耐药特性,为临床抗菌药物的合理使用提供依据.方法 收集深圳市人民医院头孢西丁耐药的大肠埃希菌临床分离株110株.提取菌株的质粒DNA,采用多重PCR法检测AmpC酶基因,并应用DNA测序确定AmpC酶的基因型;用K-B法对其进行药物敏感试验.结果 110株对头孢西丁耐药的大肠埃希菌中,13株(11.8%)AmpC酶基因扩增阳性,测序结果显示12株为DHA-1,1株为CMY-2.AmpC酶基因阳性株对亚胺培南和美罗培南100%敏感,对其它大多数药物敏感性较低.结论 该院大肠埃希菌临床分离株中质粒介导AmpC酶基因型主要为DHA-1型,对多种抗生素的耐药性高.