鸡传染性支气管炎病毒CK/CH/LHLJ/04V的分离鉴定及致弱的初步研究

从黑龙江省某鸡场发病鸡群的肾脏中分离到一株病毒,通过病毒致SPF鸡胚病变特征、对鸡外周血红细胞凝集特性、病毒粒子形态学特征以及RT-PCR鉴定等方面的研究,表明该病毒为鸡传染性支气管炎病毒,并命名为CK/CH/LHLJ/04V。通过对该病毒基因型分析以及对SPF鸡致病性试验发现该病毒为我国近年来流行的一类重要IBV的代表。将该毒株在SPF鸡胚连续传代110代(P110),取不同代次毒进行动物实验。结果显示,该毒株对SPF雏鸡的致病力随鸡胚传代次数的增加而逐渐降低。P110代毒以105.0 EID50/0.1 mL的剂量通过点眼滴鼻接种15日龄SPF雏鸡,鸡群发病率和死亡率均为0。不同代次毒接种SPF鸡对同源毒株P3代强毒的攻击均具有100%保护性。实验表明,IBV毒株CK/CH/LHLJ/04V P110对SPF雏鸡已无致病性,但仍具有良好的免疫原性,可作为研制IB弱毒疫苗的候选毒株。

Identification and attenuation of an avian infectious bronchitis virus CK/CH/LHLJ/O4V isolated in China

An avian infectious bronchitis virus(IBV) strain CK/CH/LHLJ/04V was isolated from kidney of the affected young broiler flocks in Heilongjiang province,China.The virus was examined for pathogenicity,morphology and haemagglutonating properties.Sequence analysis of the S1 protein gene demonstrated that the virus belonged to a major type of IBV identified in China in recent years.The virus was attenuated by passaging 110 times(designed as P110) through specific-pathogen-free(SPF) chicken embryonated eggs,and its pathogenicity was evaluated in SPF chickens.The results showed that strain CK/CH/LHLJ/04V P110 lost entirely pathogenicity to 15-day-old chicks and was able to stimulate full protection against homologous wild strain challenge.In conclusion,the attenuated CK/CH/LHLJ/04V P110 strain could be developed as a potential IB vaccine for controlling local Chinese IBV infections in chickens.