猪繁殖与呼吸综合征病毒山西分离株ORF5基因的序列分析

采用RT-PCR方法对2009—2011年山西省疑似猪繁殖与呼吸综合征(PRRS)阳性病料进行克隆和测序,获得5个ORF5基因片段,并对其基因序列和推导的氨基酸序列与国内外毒株进行了同源性分析。序列分析结果表明,5个ORF5基因序列之间核苷酸同源性为97.7%～98.5%,与欧洲型代表株LV、美洲型代表株VR-2332、2006—2007年国内分离的PRRSV变异株(JXA1、HuN、HUN4、HUB1)、2006年以前中国分离毒株(CH-1a、HB-1(sh)、HB-2(sh))和2个疫苗株(Resp PRRS MLV、MLV RespPRRS/Repro)核苷酸同源性分别为63.5%～64.0%、88.7%～89.2%、97.7%～99.3%、88.1%～96.7%和88.6%～89.1%;氨基酸同源性分别为56.1%～56.6%、87.8%～88.8%、96.6%～98.5%、85.9%～93.2%、86.8%～87.9%。结果表明山西地区的PRRSV流行毒株均属于美洲型,且毒株同源性很高,亲缘关系紧密。

Sequence Analysis of ORF5Gene of Porcine Reproductive and Respiratory Syndrome Virus Isolated from Shanxi Area

Through RT-PCR amplification of tissue or blood sample from Shanxi province, the 5 ORF5 gene nucleotide sequences were obtained. The obtained sequences and the deduced amino acid were analyzed and compared with the other published PRRSV strains. The nucleotide homology were 97.7% to 98.5% among 5 ORF5,comparing with LV, the strains isolated from China in 2006 to 2007, the strains isolated before 2006, Resp PRRS MLV and MLV RespPRRS/Repro, the nucleotide homology were 63.5% to 64.0%, 88.7% to 89.2%, 97.7% to 99.3%, 88.1% to 96.7%, 88.6% to 89.1%.The aniniacid homology were 56.1% to 56.6%,87.8% to 88.8%,96.6% to 98.5%,85.9% to 93.2%,86.8% to 87.9%, respectively. The results showed that the prevalent PRRSV strains in Shanxi belong to North American genotype which had high homology and correlative genetic relationship.