湖北部分地区鸭疫里氏杆菌的分离鉴定

Isolation and Identification of Riemerella anatipestifer in Some Areas of Hubei Province

对湖北省部分地区鸭疫里氏杆菌（RA）进行分离鉴定。应用胰蛋白大豆琼脂（TSA）培养基的分离培养及染色试验、生化试验、PCR鉴定,得到86株RA。染色观察各地RA分离株的细菌形态一致,符合RA特征;生化试验显示86株RA的生理生化特征相似,基本符合RA特征;应用建立的PCR技术均可从这些菌株扩增到RA的特异性基因片段。通过与阳性血清所做的玻片凝集试验,证明分离出的RA菌株全部属于血清1型。8个地区（市）的20个养鸭场皆分离出RA。经统计,脑组织中RA分出率（81/86）明显高于心血（53/86）及肝组织（49/86）;10日龄~21日龄鸭最易感,且鸭感染RA呈明显的年龄抵抗性;樱桃谷鸭最易感。在RA阳性病料中同时分离到28株大肠埃希菌,显示其与鸭大肠埃希菌混合感染率高达32.56%。人工感染鸭的致病性试验结果显示,RA的致病力较强,与大肠埃希菌混合感染的致病力更强。结果表明鸭疫里氏杆菌病已成为湖北省养鸭业最常见的、危害最大的细菌性传染病之一。

Riemerella anatipestifer（RA） was identified from duck farms in Hubei.The bacteria were identified as RA by the Gram stain test,biochemical reaction and PCR amplifications of the outer membrane gene.Each RA strain originated from different districts had identical morphology,approximate biochemical characteristics and Specific gene fragment of RA was amplified.Slide agglutination test demonstrated that all the RA isolates belong to serotype 1.The RA isolates was isolated on 20 duck farms with different variety ducks in 8 counties of Hubei.The isolation rate of brain（81/86） was significant higher than that of heart blood（53/86） and liver（49/86）.Ducklings of 10 day-old to 21 day-old and Cherry valley ducks were more susceptive than that of others to RA infection.A significant age resistance against RA infection was observed during the period of 10 day-old to 42 day-old.28 Escherichia coli were isolated concurrently from the RA positive ducks,and with a 32.56%co-infection rate.Challenge test showed that RA is virulent and even more virulent when co-infected with E.coli.The results showed that RA infection was one of the most common causes for the losses in duck industry.