两株高致病性PRRSV河北分离株NSP2和ORF5基因的克隆及遗传变异分析

从河北省保定某两个猪场疑似高致病性猪繁殖与呼吸综合征病料中分离出能引起Marc-145细胞病变的病毒,经RT-PCR鉴定证明,该病毒为美洲型PRRSV,分别命名为BD1和BD2株。并将其克隆、测序,与国内外PRRSV分离株的Nsp2和E基因序列进行了比较。结果表明,与PRRSV高致病性毒株JXA1、GD、WUH1、SY0608、HUN0701的核苷酸序列同源性为95.3%~96.5%,BD1和BD2株ORF5基因存在部分突变,没有缺失,与国内高致病性PRRSV分离株JXA1、HUB1、Jiangxi-3、Henan-1、WUH1的同源性高达97.2%~99.3%。

Isolation of Two Hebei Strains of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus and sequence Analysis of Their Nsp2 and ORF5 Genes

Two strains of virus causing CPE of Marc-145 cell lines was isolated from samples of dead pigs with highly pathogenic porcine reproductive and respiratory syndrome in Baoding areas, Hebei Province. The two virus isolates were identified to be porcine reproductive and respiratory syndrome virus (PRRSV) by RT-PCR,and designated as BD1and BD2. And the Nsp2 and ORF5 genes of BD1and BD2 were cloned and sequenced respectively. Compared with those of native and foreign PRRSV strains,sequencing results showed that Nsp2 genes of BD1 and BD2 strain shared 95.3% to 96.5% homologies with those of JXA1、GD、WUH1、SY0608 and HUN0701 strains. ORF5 genes had a few mutation but no deletion,and shared 97.2% to 99.3% homologies compared with those of JXA1,HUB1,Jiangxi-3,Henan-1 and WUH1.