1株野鸭源鸡贫血病病毒的分离鉴定及其编码区基因序列分析

Isolation,identification and coding region gene sequence analysis of a strain CAV with the wild duck origin

利用MDCC细胞系从东北地区采集的死亡野生鸟类样品中分离获得1株禽类病毒,对该病毒进行特异性PCR、特异性间接免疫荧光法等系统鉴定后,证实该分离株为鸡贫血病病毒(CAV),命名为WDNE110501株。利用PCR方法克隆出其编码区基因片段,测序结果表明,WDNE110501株的编码区全长为1823bp,无碱基缺失或插入。并将该基因序列和推导的氨基酸序列与国内外已发表的34个CAV株编码区基因进行同源性和亲缘关系的比对分析,同源性为96.1%～99.8%;氨基酸的同源性为89.8%～99.7%,与国内毒株harbin的差异最小,与国外最近的是美国毒株98D02152。序列比较表明CAV的3个编码基因VP1、VP2和VP3均有一定程度变异,以VP1变异性最大,且在不同毒株间的这3个阅读框的氨基酸序列变异是互不相关的。这是首次在野生鸟类中分离出CAV病毒,提示了我们野生鸟类在鸡传染性贫血病病毒传播和分布中可能起到一定作用。

A CAV virus strain was successfully isolated from the samples of died wild birds which collectted from the northeast China by passaging in MDCC cells,The virus was identified as CAV virus based on specificity PCR results and indirect immunofluorescence,called WDNEll0501. The coding region gene of the strain was amplified by PCR which the length is 1 823 bp without absence and insertion of the basic group and shared 96. 0%-99. 8; homology of nueleotide sequences and 89.80/00-99.7% homology of amino acids with those of 34 CAV strains,the minimum difference of internal stain harbin and external stain 98D02152 of USA. Sequence data indicated there were some mutations in 3genes VP1, VP2 and VP3. Relatively, VP1 was less conservative than VP2 and VP3. Among different strains,mutations in these 30RF genes were not correlated. This is the first time to isolate the CAV virus from the wild birds,indicating that the wild birds may play a role in dissemination and distribution of CAV virus.