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。
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-media- ted 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 multipledrug resistance, 20 were determined as ESBLs gene positive, 21 as class 1 integrons sequence, and 20 as aerAB-tolC gene. Conclusions The resistance rates of AmpC β-lactamaseproducing 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.
出处
《中华实验和临床感染病杂志（电子版）》
CAS
2007年第3期144-148,共5页
Chinese Journal of Experimental and Clinical Infectious Diseases(Electronic Edition)
基金
国家自然科学基金项目(30571654)
安徽省自然科学基金项目(070413110)
关键词
AMPC酶
大肠埃希菌
耐药
AmpC β-lactamases
Escherichia coil
Resistance
