健康猪体内塞尼卡病毒的分离和鉴定

Isolation of Senecavirus A from clinical healthy pigs

塞尼卡病毒(SVA)属于小核糖RNA病毒科塞尼卡病毒属,可以引起猪的水泡样病变、跛行和新生仔猪突然死亡等。为了解SVA的特性,本研究将从健康猪体内鉴定的SVA阳性样品接种BHK-21细胞分离SVA,采用PCR扩增其VP1基因,并分析其遗传变异特点。结果显示,10份SVA阳性样品中有2份(GXT91和GXT94)能够在BHK-21细胞增殖并产生明显的细胞病变,可达10^7.6TCID50/mL,其VP1基因与SVA参考株NC_011349的核酸同源性为90.2%~90.6%,推导氨基酸同源性为96.7%~97.1%,进化树显示新分离的GXT91和GXT94病毒株属于流行分支II。本研究为SVA的疫苗研制奠定了基础。

Senecavirus A(SVA)is a single strand positive RNA virus belonging to the Senecavirus genus of family Picornaviridae,which causes porcine idiopathic vesicular lesions on the snout and coronary bands,lameness and acute death of newborn piglets.SVA has been reported in several provinces in China.In order to understand the characteristics of SVA,this paper tried to isolate SVA by inoculating on BHK-21 cell with SVA positive samples by real-time RT-PCR which collected from healthy pigs in slaughterhouse.Then the VP1 gene of SVA was amplified by PCR and analyzed for its genetic variation.The results showed that 2(GXT91 and GXT94)out of 10 positive samples obviously induced cytopathic effect on BHK-21 cells.The TCID50 titer of isolate GXT94 reached 107.6/mL.Further analysis showed that the nucleic acid homology of VP1 gene was 90.2%to 90.6%between SVA isolates and reference strain NC_011349 and the amino acid homology was 96.7%to 97.1%.The isolates of GXT91 and GXT94 were categoried into the second branch in the evolutionary tree of all SVAs.This study laid the foundation for the potential development of SVA vaccine.