百色市鸭疫里默氏杆菌病的流行病学及其病原的分离与鉴定

2006年5月~2007年3月间,对百色市所辖12个县(区)的86个养鸭场(户)多个品种的鸭群进行鸭疫里默氏杆菌(R iem erella ana tip estif er,RA)病发生和流行情况的调查。结果从186羽具有浆膜炎病变的死鸭及其同群病鸭的肝和脑中分离到62株RA可疑菌株,通过生化试验证明它们基本符合RA的特征;应用建立的PCR技术均可从这些菌株扩增到RA的特异性基因片断;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;在鸭疫里默氏杆菌阳性病料中,RA单一感染的占25.81%(16/62)、RA与大肠杆菌混合感染率56.45%(35/62)、RA与沙门氏杆菌混合感染率17.74%(11/62);病例中大肠杆菌单独感染占6.99%(13/186);2~5周龄雏鸭最易感染,北京鸭最易感染;药敏试验表明,大多数RA分离株对头孢类药物表现高敏,但总体上耐药性比较严重;分离株的致病性试验结果显示,RA的致病力比较强,与大肠杆菌的混合感染的致病力更强。本研究证明鸭疫里默氏杆菌病已成为百色肉鸭养殖业最常见的、危害最大的传染病之一。

Isolation and identification of Riemerella anatipestifer and epidemiology of its infection in Baise duck industry

During 2006.05~2007.03,an epidemiological survey of the infections of Riemerella anatipestifer(RA) was made on 86 duck farms with different variant meat-type duck in 12 counties of Baise.62 isolates showed typical biochemical characteristics of RA were recovered from 186 birds of dead or diseased with serositis.Specific gene fragment of RA was amplified from all the isolates and they were all belonged to serotype 1 when a slide agglutination test was performed with the positive reference serum.Within the positive cases of RA infection 25.81%(16/62) were single infection,56.45%(35/62) were coinfected with Escherichia coli and 17.74%(11/62) were coinfected with Salmonella.6.99%(13/186) of all the cases were single infection of E.coli.Ducklings of 2~5 week-old and Peking duck were the most susceptive to RA infection.Drug sensitive test showed that although most of the RA isolates were highly sensitive to cephalothin,the resistances to the common antibiotics were prevalent among the isolates.Challenge test showed that RA is virulent and even more virulent when coinfected with E.coli.The results of the study demonstrated that RA infection has been one of the most common causes for the losses in duck industry.