阳江地区某猪场塞内卡病毒抗原和抗体的检测与分析

Detection and analysis of antigen and antibody of Seneca virus from a pig farm in Yangjiang

塞内卡病毒是新发现的一种小RNA病毒,能使猪产生类似水疱样病变,并引起仔猪死亡。塞内卡病毒作为外来病原,近几年呈现蔓延趋势。从广东阳江地区某猪场采集病变组织和血清进行检测分析,针对塞内卡病毒VP1-2A基因进行RT-PCR扩增,得到特异性的单一条带。对PCR产物序列分析表明,与2015年美国毒株USA/GBI29/2015的同源性最高、为99.2%,而与我国2017年毒株CH-HN-2017的同源性为97.1%。将水泡皮处理后接种PK-15细胞,盲传4代产生显著病变,滴度可达107TCID50/0.1mL。对采集的16份血清进行抗体中和试验表明,发病种猪的抗体效价最高达到1︰4096,9头种猪全部感染SVA,发病率为66.7%,总感染率为68.8%。

Seneca virus A(SVA)is a newly discovered picornavirus that produces similar vesicle-like lesions in pigs and causes death of piglets.In recent years it outbroke and showed a trend of spread.The tissues and serum were collected from a pig farm in Yangjiang,for testing and analysis.A specific single band was amplified from RT-PCR of the VP1-2A gene of Seneca virus.Sequence analysis of PCR products showed that this stain was most homologous(99.2%)with USA/GBI29/2015,a strain from USA in 2015,and showed 97.1%homology with CH-HN-2017,a stains from China in 2017.The pathological tissue was grinded and the fluid was inoculated to cell line PK-15,and the cells turned out a significant lesion in the 4 generation,and the titer reached 107 TCID50/0.1mL.The antibody neutralization test of 16 serum samples showed that the highest titer of antibody was 1:4096 in sick breed pigs.All 9 breed pigs were infected with SVA.The incidence of SVA was 66.7%and the total infection rate was 68.8%.