鸡致病性大肠杆菌的分离鉴定及耐药基因的检测

从山东省滕州市某种鸡场的19只死胚及出壳弱雏中分离出6株大肠杆菌,平均分离率为36.84%。生化鉴定表明,这些致病菌均符合大肠埃希氏菌的生化特性。本实验用平板稀释法对6株鸡源致病性大肠杆菌进行了药敏实验,结果6株菌对五大类抗生素(氨基糖甙类、四环素类、氯霉素类、磺胺类、硝基呋喃类)的10种药物的耐药性以卡那霉素最高,四环素次之,呋喃妥因最低。设计了4对引物,采用PCR技术,对6株鸡源大肠杆菌的耐药基因进行了检测并对所得耐药基因进行了扩增及序列测定。

Isolation,Identification and Drug Resistance Gene Detection of Pathogenic E.coli from Chicken

Six strains of Escherichia coli were separated from19 dead embryos and weak chicks in a farm of Tengzhou city,Shandong Province.The average separation rate was 36.84%.Biochemical identification showed that these pathogenic strains were consistent with Escherichia coli in biochemical characteristics.Drug sensitivity experiments were carried out with plate dilution method.The results showed that six E.coli strains were resistant to 10 drugs in five antibiotics classes (aminoglycosides,tetracycline,chloramphenicol,sulfonamides,nitrofurans).The resistance to kanamycin was the highest,followed by tetracycline,and nitrofurantoin was minimum.Four pairs of primers were designed and the resistance genes of six E.coli strains from chickens were detected and the obtained resistance genes were amplified and sequenced.