河北省犊牛腹泻大肠杆菌致病性及耐药性分析

为确定河北省犊牛腹泻大肠杆菌的致病性与耐药性,本研究对2018年1月至2019年6月期间从河北省石家庄、保定、承德、唐山、廊坊的部分肉牛场腹泻犊牛样品中分离到的50株大肠杆菌进行了致病性试验、药物敏感性试验、毒力基因和耐药基因检测。结果显示:50株分离菌均对小鼠具有致病性,致病菌占比100%(50/50)。毒力基因fyuA、irp2、eaeA、ler检出率分别为68.0%、66.0%、34.0%、34.0%。50株分离菌均对15种抗生素中的2种及以上表现为耐药,对10种及以上抗生素耐药的菌株占比达34%(17/50);分离菌对土霉素、磺胺对甲氧嘧啶、磺胺间甲氧嘧啶、替米考星4种药物表现为高度耐药,耐药率分别为90%、90%、94%、100%。除四环素类tetD基因检出率为0外,其它耐药基因均有检出,其中四环素类tetC、氨基糖苷类aadA1、喹诺酮类gyrA、gyrB基因检测率高达100%。试验的50株大肠杆菌均具有较强的毒力和多重耐药性。本研究为河北省大肠杆菌所致犊牛腹泻病的防治提供了实验依据。

Pathogenicity and drug resistance of diarrhea Escherichia coli in calves in Hebei province

To determine the pathogenicity and drug resistance of diarrhea E. coli from calves in Hebei province, 50 strains of Escherichia coli were isolated from diarrhea calves in some beef cattle farms in Shijiazhuang, Baoding, Chengde, Tangshan and Langfang of Hebei province from January 2018 to June 2019, and the pathogenicity, drug sensitivity, virulence and drug resistance genes of the isolates were tested. The results showed that all of the 50 isolates were pathogenic to mice, and the pathogenic bacteria accounted for 100%(50/50). The detection rates of virulence genes fyuA, irp2, eaeA and ler were 68.0%, 66.0%, 34.0% and 34.0%respectively. The 50 isolates were resistant to 2 or more of the 15 antibiotics, and 17 out of 50 isolates(34%) were resistant to 10 antibiotics. The isolates were highly resistant to oxytetracycline, sulfamonomethoxine, sulfametoxydiazine and temicosin, with resistance rates of 90%, 90%, 94% and 100%, respectively. Except tetracycline tetD gene detection rate was 0, other resistance genes for testing were all detected, tetracycline tetC, aminoglycoside aadA1, quinolone gyrA, gyrB gene detection rate was as high as 100%. The tested 50 E. coli isolates had strong pathogenicity and multiple drug resistance. This study provided a basis for prevention and treatment of calf diarrhea caused by E. coli in Hebei.