【摘要】 目的了解安徽省35所医院自临床分离的402株大肠埃希菌产质粒介导AmpC酶及对常用抗菌药物的耐药情况,揭示其相关耐药机制,以指导临床合理用药。方法以三维试验筛选产AmpC酶株;多重PCR检测产质粒介导AmpC酶菌株,对产质粒介导AmpC酶菌株用PCR方法检测超广谱β-内酰胺酶(ESBLs)基因、Ⅰ类整合子基因盒插入序列和主动外排系统acrAB-tolC基因。结果检出产质粒介导AmpC酶菌株28株(7.0%),其中两株经测序比对证实为新的质粒ampC基因型。产酶菌株对常用抗菌药物,除亚胺培南、美罗培南都敏感外,对其他大多数抗菌药物耐药率均高于非产酶株。28株产酶菌株中有23株表现为多重耐药,20株检测出各型ESBLs基因,21株扩增出Ⅰ类整合子基因盒插入序列,20株主动外排系统acrAB-tolC基因阳性。结论产质粒介导AmpC酶大肠埃希菌对临床常用抗菌药物的耐药率均较高,多重耐药现象普遍,同时存在多种耐药机制,其中以产生灭活酶和Ⅰ类整合子介导的耐药机制为主。对产酶菌株临床经验用药可选用碳青霉烯类、阿米卡星、四代头孢菌素类抗菌药物。更多还原

【Abstract】 Objective To investigate the production and resistance of plasmid-mediated AmpC β-lactamase-producing Escherichia coli(E.coli)and analyze their associated resistance mechanism and guide rational use of antibiotics.Methods Three-dimensional extract test was adopted to detect AmpC β-lactamases.The plasmid-mediated AmpC β-lactamases were detected by multiplex PCR.Extended-spectrum β-lactamases(ESBLs)gene,inserted gene cassettes of class 1 integrons and active efflux system acrAB-tolC gene were amplified by PCR.Results Among the 402 isolates collected,28(7.0%)produced plasmid-mediated AmpC β-lactamases.DNA sequence analysis confirmed that 2 were novel ampC genes.The resistant rates of AmpC β-lactamase-producing strains against most kinds of antibiotics were higher than the unproducing strains.They were all sensitive to imipenem and meropenem.Among the 28 strains,23 were multiple-drug resistance,20 were determined as ESBLs gene positive,21 as class 1 integrons sequence,and 20 as acrAB-tolC gene.Conclusions The resistance rates of AmpC β-lactamase-producing E.coli against most kinds of antibiotics reach a high level.The AmpC producers are multiple-drug resistance and there may be several resistance mechanisms,in which class 1 integrons and production of AmpC and ESBLs were the main ones.Carbopenems,amikacin and fourth cephalosporins should be chosen in clinical empirical medication.更多还原