一株鸡传染性喉气管炎病毒的分离鉴定及TK基因分析

Isolation and identification of infectious laryngotracheitis virus from Heilongjiang province and sequence analysis of the TK gene

黑龙江省牡丹江市某养鸡场28周龄蛋鸡发生以呼吸困难、咳血和产蛋下降为主要症状的疾病。本研究利用特异性引物,从发病鸡喉头及其分泌物中扩增出鸡传染性喉气管炎病毒(ILTV)gB基因的567 bp大小片段;将发病鸡喉头及分泌物处理后接种鸡胚,在鸡胚绒毛尿囊膜(CAM)上形成痘斑。病毒接种鸡胚肾细胞48 h后电镜下可以观察到典型的疱疹病毒粒子形态,并且该分离株能够与ILTV单克隆抗体发生特异性反应。动物回归试验显示,感染的SPF鸡出现典型ILT症状,并能够从发病鸡体内重新分离到ILTV,由此判定该分离株为ILTV,并将其命名为MDJ0442。根据NCBI登录的ILTV序列(HQ630064)设计引物,以MDJ0442基因组为模板,PCR扩增TK的基因片段,进行测序和序列分析。结果表明,与其他ILTV参考病毒株相比,TK基因的核酸同源性为99.62%。本研究可以为ILTV的流行病学调查和分子生物学研究提供参考。

A virus was isolated from layer flock in a chicken farm of Mudanjiang area which exhibited severe respiratory clinical signals and resulted in significant reduction of egg production. The virus was identified as infectious laryngotracheitis virus （ILTV） by amplification of a 567 bp fragment specific to conserved region of ILTV gB gene, observation of the virus particles under electron microscope and the sequence analysis of the TK gene. Furthermore, the virus pathogenic tests showed that the virus isolate was able to caused 70% morbidity and 20% mortality in 8 week SPF chickens which indicated the isolate was a virulent ILTV. These results could be useful for the research of epidemiology and molecular biology of ILTV.