Rao M Sreenivasa, Raj G Dhinakar, Manohar B Murali
Department of Pathology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai 600 007, India.
Avian Pathol. 2002 Oct;31(5):507-13. doi: 10.1080/0307945021000005888.
The virulence of two vaccine strains and two field strains of Newcastle disease virus (NDV) for the female reproductive tract of chickens was assessed using oviduct organ cultures (OOC) prepared from precociously-induced oviducts in young chicks by oestrogen treatment. Ciliostasis, haemagglutination and virus isolation from infected OOC supernatants, histopathology and immunoperoxidase test results indicated the pathogenic nature of both vaccine and virulent NDVs for the precocious oviducts. The virulent viruses, mesogenic and lentogenic vaccines caused damage in that order of magnitude and the uterus had a higher susceptibility than oviducts. One virulent and the mesogenic strain of NDV were used for in vivo trials. The pathogenicity was assessed in oestrogen-treated infected chickens using histopathology and immunoperoxidase test. The vaccine virus produced transient damage up to 6 days post-infection, while the damage with the virulent isolate persisted for at least 9 days post-infection. This technique could be a pointer to possible variations in virulence of NDV vaccine and field strains, and warrants further investigation. The potential value of OOC from young chickens for testing the possibility of NDV vaccines causing damage by themselves and offering protection against damage of the reproductive tract caused by virulent isolates is emphasized.
利用经雌激素处理的幼雏早熟诱导输卵管制备的输卵管器官培养物（OOC），评估了两种新城疫病毒（NDV）疫苗株和两种野毒株对鸡雌性生殖道的毒力。来自受感染OOC上清液的纤毛停滞、血凝和病毒分离、组织病理学和免疫过氧化物酶检测结果表明，疫苗和强毒NDV对早熟输卵管均具有致病性。强毒病毒、中等毒力疫苗和弱毒疫苗造成的损害依次递减，且子宫比输卵管更易受感染。选用一株强毒和一株中等毒力的NDV毒株进行体内试验。采用组织病理学和免疫过氧化物酶检测评估雌激素处理的感染鸡的致病性。疫苗病毒在感染后6天内产生短暂损伤，而强毒株感染造成的损伤在感染后至少持续9天。该技术可能提示NDV疫苗株和野毒株毒力的潜在差异，值得进一步研究。强调了利用幼雏的OOC检测NDV疫苗自身造成损伤以及预防强毒株对生殖道造成损伤的可能性的潜在价值。
