淡水养殖鱼大肠埃希菌分离鉴定与耐药性研究

Identification and Antimicrobial Resitance of Escherichia coli Isolated from Farmed Fishes

为获取长春地区鱼源大肠埃希菌的耐药性情况,采集市场及养殖场淡水鱼样品进行大肠埃希菌的分离鉴定。测定分离株对19种抗菌药物的耐药性,并检测9种耐药基因和25种毒力相关基因,测定ESBLs表型大肠埃希菌分离株的O抗原血清型。结果表明,322份样品分离获得36株大肠埃希菌,分离率为11.2%,其中18株为A群,其余为B1群。分离株对头孢类抗生素、青霉素类抗生素、四环素和复方新诺明耐药性相对较高,耐药率不低于22%。9株分离株检测到四环素耐药基因tet(A),13株ESBLs表型菌株检测到1群blaCTX-M基因。ESBLs表型菌株的血清型中O164为优势血清型。部分菌株检测到毒力相关基因,包括fimC(94.4%)、ompT(30.6%)和ucD(5.6%)。结果表明,获得了长春地区鱼源大肠埃希菌带菌及耐药性情况,为淡水养殖鱼细菌性疾病的防控提供了一定的参考。

To investigate the prevalence of antimicrobial-resistance Escherichia coli isolated from farmed fishes in Changchun,the samples were collected from fish markets and fish farms.The resistance of isolates to19antimicrobial agents were detected by BD Phonenix System,9resistance-associated genes and25virulence-associated genes were PCR-amplified.O antigen serotypes of ESBLs phenotype isolates were tested also.A total of36E.coli strains were isolated from322samples.The isolation rate was as low as11.2%.Among them,18strains belonged to A group,and the others belonged to B1group.More than22%isolates showed resistance to cephalosporin,penicilline,tetracycline and sulfamethoxazole/trimethoprim.The tetracycline resistance gene tet(A)was detected in9isolates,and the blaCTX-M group1genes were present in13ESBLs E.coli.O164was prevalent in ESBLs strains.Partial isolates carried the virulence-associated genes,including fimC(94.4%),ompT(30.6%),iucD(5.6%).These findings provided not only the epidemic status of germ-carrying and antimicrobial-resistance of E.coli isolated from farmed fishes in Changchun,but also a reference for prevention and control of bacterial infections in farmed fishes.