牛传染性鼻气管炎病毒攻毒方式的对比研究

本试验旨在建立牛传染性鼻气管炎病毒的攻毒模型,明确病毒在牛体内的分布及确定最佳攻毒方式,建立牛传染性鼻气管炎的发病标准,用来评价IBRV LNM弱毒疫苗的保护效力。试验共使用健康断乳牛9头,设鼻内喷雾组、滴鼻组和对照共3组,每组3头牛。将实验室分离保存的IBRV LN01/08强毒株采用鼻内喷雾和滴鼻两种方式接种试验组动物后,连续14 d,每日观察临床症状,监测体温及采集鼻拭子,对收集的试验数据进行对比分析。选取临床发病不同时期剖杀动物,采取主要脏器进行病毒分离。结果显示,所有动物攻毒后有不同程度的临床表现,以鼻内喷雾组临床表现最为严重,剖检可见肺部病变明显。病毒主要分布在呼吸道和眼结膜组织中。研究结果显示,采用IBRV自然感染方式攻击动物,喷雾方法攻毒临床效果明显强于滴鼻方式,保证了临床发病模型的建立,可以用来IBRV疫苗免疫效果评价,为研制IBR疫苗提供前提基础。

Comparison Research of Infectious Bovine Rhinotracheitis Virus Challenge

This study is to determine the most effective inoculation mode and the distribution of infectious bovine rhinotracheitis virus(IBRV) in experimental animals,which is used to evaluate the protective efficiency of attenuated vaccine strain LNM.9 cows post-ablactation were divided into test groups(nasal sprays group,nasal drops group) and control group,each group contains 3 cows.Test groups were inoculated with virulent strain of LN01/08 by nasal sprays and nasal drops,respectively,and the data of daily clinical symptoms,body temperature and nasal swab were collected for consecutive 14 days post-inoculation.Experimental animals in different clinical period post-onset were killed and main internal organs were collected for virus isolation.The test results showed that all animals post-inoculation developed different extent clinical signs(the nasal spray group animals performed more seriously),and IBRV were most distributed at tissues of respiratory and ocular conjunctiva.It is concluded that experimental animals inoculated with IBRV by nasal sprays was better than that by nasal drops,which could provide a basis for develop IBR vaccine and evaluate immune effect of IBRV vaccine.