鸡马立克氏病病毒与大肠杆菌混合感染症的病原分离鉴定

鸡呼吸道病流行病学调查的过程中,在韶关市某养鸡场观察到一群100日龄广西黄肉仔鸡发生了以呼吸道症状为主要临床表现的疾病,死亡率达10%.病理解剖学检查可见病鸡有单一或多器官肿瘤病变(4/8)、典型腹膜炎病变(3/8)和肿瘤与腹膜炎病变并存(2/8).在病鸡肿瘤组织切片中可见典型MD病理组织学变化.采用CEF接种方法,从有肿瘤和腹膜炎病鸡的羽髓液中分离到MDV.在病鸡的心、肝、脾等脏器分离到大肠杆菌O78血清型菌株.研究结果表明:HVT疫苗免疫鸡群MDV强毒株和E.coliO78血清型菌株以混合感染形式存在,病鸡出现以呼吸道症状为主的临床表现,死亡率明显增加.

Isolation and identification of the pathogens from chickens co-infected with MDV and E.coli

A regional survey of epidemiological chicken diseases is reported to observe a disease mainly of respiratory clinic symptoms with 10% mortality in a 100-day-old Guangxi yellow broiler flock in Shaoguan,Guangdong Province.Gross examinations of the diseased chickens' heart,liver,spleen and kidney found out tumors in different sizes and pathological changes of typical peritonitis.Further histopathologic examinations of the tumors showed typical MD lesions.Feather follicle epithelium of the diseased chickens was experimentally inoculated into the chicken embryo fibroblasts(CEF),which developed into pathological changes of Marek's disease virus(MDV);and pathologic Escherichia coli(E.coli) serotype O_(78) was isolated from diseased chickens' heart,liver,spleen and kidney.The disease in this broiler flock was proved to be induced by co-infection of MDV and pathologic E.coli serotype O_(78).The results show that there is high mortality in HVT vaccinated commercial chicken flocks co-infected with MDV and E.coli.