摘要
用RT-PCR方法对山东省疑似传染性法氏囊病（IBD）组织样品进行检测,对阳性样品进行了病毒分离,设计引物扩增出分离病毒的全基因组。谱系分析表明,除WF株外,其他分离株与国内大部分强毒株位于同一个谱系。序列分析表明,LY、QD、BZ、LC、TA、DZ、HZ、JN分离株VP2七肽基序均为S-W-S-A-S-G-S,在第222、253、256、279、284、294和299位上的氨基酸残基分别是A、Q、I、D、A、I和S,具有IBDV强毒的分子特征。攻毒试验表明,LY株产生明显IBD病变,死亡率为40%（2/5）,为强毒株,结果与序列分析一致。WF株与B87和Gt疫苗株位于同一谱系,VP2分子特征也与Gt弱毒株相同,攻毒试验显示WF株为弱毒株。同源性分析表明,LY、QD、BZ、LC、TA、DZ、HZ、JN与国内分离的强毒株之间VP2氨基酸序列的同源性为93.3%~99.8%,与现行商品疫苗毒株B87和Gt的VP2氨基酸序列同源性分别为94.1~96.2%和94.5~96.9%;WF分离株与国内分离株之间VP2氨基酸同源性为95.6%~99.2%,与疫苗株B87和Gt株VP2氨基酸同源性分别为99.2%和99.6%。本文对山东省流行的鸡传染性法氏囊病毒进行了分子流行病学分析,对病毒的基因组学和致病性进行了初步研究,此研究对了解本病的流行现状,分析病毒变异规律具有重要意义。
Tissue samples with suspected infectious bursal disease （IBD） from Shandong province were detected by RT-PCR method, and viruses were isolated from the positive samples. The whole genomes of isolates were amplified with designed primers. Phylogenetic analysis showed that these isolates except WF strain belonged to the same lineage with most virulent strains in the country. Sequence analysis showed that VP2 seven-peptide motif of LY, QD, BZ, LC, TA, DZ, and HZ isolates were S-W-S-A-S-G-S, and amino acid residues at positions 253, 253, 256, 256, 284, 294 and 299 were A, Q, I, D, A, I and S respectively, with molecular characteristics of virulent IBDV. Challenge test showed that LY strain induced obvious IBD lesions, mortality was 40% （2/5） , referred as virulent IBDV, which was consistent with the sequence analysis. WF strain and vaccine strains B87 and Gt belonged to the same lineage, their VP2 molecular features were same as the Gt attenuated strain, and challenge experiments showed WF strain as attenuated IBDV. Sequences analysis indicated that the homology of amino acid sequences of VP2 of LY, QD, BZ, LC, TA, DZ, and HZ isolates and other virulent strains in the country was 93.3% -99.8%, while with the vaccine strains B87 and Gt were 94.1 - 96.2% and 94.5 - 96.9% respectively. The homology of amino acid sequenc- es of VP2 of between WF isolate and other isolates was 95.6% - 99.2%, and with the vaccine strains B87 and Gt were 99.2% and 99.6% respectively. In this paper, molecular epidemiology of chicken infectious bursal virus was analyzed in Shandong province, and genomics and pathogenicity of the virus were studied preliminarily. It is of great significance to understand the epidemic situation and analysis of the virus variation.
出处
《中国动物检疫》
CAS
2015年第3期11-15,47,共6页
China Animal Health Inspection
