雏鹅新型病毒性肠炎病毒弱毒株的培育及其特性研究

应用在鸭胚成纤维细胞上连续传代的方法 ,获得了由雏鹅新型病毒性肠炎病毒强毒株(NGVEV CN株 )致弱的弱毒株 (CN4 0 株 )。该弱毒株TCID50 为 10 - 8.0 83,具有良好的安全性和稳定性 ,在易感 1日龄雏鹅连传 8代不返强。该弱毒具有良好的免疫原性 ,最小免疫剂量为 10 0 0 0TCID50 ,免疫后 3d产生部分免疫力 ,5d产生坚强免疫力。口服免疫效果最好 ,对雏鹅免疫期在30d以上。该弱毒株能够干扰强毒在雏鹅体内繁殖 ,进入鹅体后能够进行一定程度繁殖并排泄出体外 ,使同居雏鹅感染并获得一定程度免疫力。临床使用后可极显著降低雏鹅的死亡率。

Growth of the attenuated vaccine strain of new type gosling viral enteritis virus and study on its characteristics

The attenuated vaccine strain CN 40 was obtained after the fullvirulence strain NGVEV CN grew in duck embryo fibroblast monolayer cells for 40 generations. CN 40 is safe and stability to goslings, and doesn't become fullvirulence when it grow in one day old goslings for 8 generations.CN 40 has good immunogenic , and its least immune dose is 10 thousands TCID 50 , immunity can be obtained partly after 3 day and fully after 5 day. The best immune effect can be acquired by oral CN 40 strain, and the protection period is over 30 days. The growth of fullvirulence NGVEV CN strains in goslings can be interfered by CN 40 strain. CN 40 strain can grow in gosling body and be excremented out. Goslings living together with vaccined goslings can be infected and partly immune can be acquired. Mortality can be lowered observably from vaccined goslings in fields.straincangrowingoslingb