11型鸭疫里默氏杆菌分离鉴定及致病性研究

Isolation and identification of serotype 11 Riemerella Anatipestifer

从江苏某免疫鸭场的病死鸭中分离出1株细菌,经形态特性、生化试验、PCR扩增和血清型鉴定,证明该菌为血清11型的鸭疫里默氏杆菌(RA)。人工感染试验显示,106CFU/mL RA经肌肉注射后可导致鸭发病死亡,病死鸭的多个脏器组织均可分离到细菌,而滴鼻接种引起症状所需的细菌剂量为108CFU/mL;对106CFU/mL细菌肌肉注射致死鸭的脏器进行细菌计数,以法氏囊的含菌量最高;病理学变化涉及心、肝、脾、肺、胰、脑、肠粘膜和法氏囊。结果表明,江苏地区存在新的RA血清型,法氏囊是该细菌感染的一个重要靶器官。

A serotype 11 strain of Riemerella anatipestifer was isolated from a dead vaccinated duck in Jiangsu province. Experimental infection of the cherry valley ducks with 10^6 CFU/mL by the intramuscular route, or 10^8 CFU/mL by the intranasal route developed clinical symptom and death. R. anatipestifer could be isolated in blood from heart, liver, lung, kidney, brain and bursa of Fabricius. The bacterial concentration in bursa of Fabricius was the highest. Gross lesions in affected birds involved heart, liver, spleen, lung, pancreas, brain, enteric mucous membrane, and bursa of Fabricius. These results indicated that a new serotype of R. anatipestifer existed in Jiangsu province and bursa of Fabricius was the primary target organ.