一株塞内卡病毒A全基因组序列测定与致病性分析

本研究旨在明确塞内卡病毒A（Senecavirus A，SVA）FJLY株的基因组特性及其与其他毒株的同源性关系，并了解SVA-FJLY株的致病性。以分离自福建省某养殖场中的一株SVA-FJLY株为研究对象，参照其原型毒株SVV-001（GenBank No.DQ641257.1）全基因组序列设计5对引物，通过RT-PCR扩增、测序、拼接，获得SVA-FJLY株全基因组序列并进行序列分析；并通过滴鼻攻毒3~4周龄仔猪。结果表明，SVA-FJLY株基因组全长7 275 bp（不包括PolyA），SVA-FJLY株基因组存在一个多聚蛋白、VP1蛋白和VP2蛋白。SVA-FJLY株与参考毒株之间的基因组一级结构有较高的相似性，与HeB01-2017株（MF967574.1）相似性最高，达98.5%；而与SVA原型毒株SVV-001株（DQ641257.1）的相似性较低，为93.9%。SVA-FJLY株与国内几个毒株属于同一个分支，与国内的HeB01-2017株亲缘关系最近，同时与国外Colombia-2016株（KX857728.1）的亲缘关系最近。通过动物试验发现试验组猪攻毒10 d后，试验组2/3发病，对照组3/3正常，未出现仔猪死亡。通过全基因组序列测定获得了SVA-FJLY株全基因组序列并进行序列分析，明确SVA-FJLY株的基因组特性及其与其他毒株的相似性关系，了解了SVA-FJLY株的致病性，为SVA的反向遗传学和疫苗的研制提供参考依据，同时也丰富了SVA的基因组信息数据库。

Genome Sequencing and Pathogenicity Analysis of Senecavirus A,SVA-FJLY

The aim of this study was to clarify genomic characteristics, homology, and pathogenicity of Senecavirus A (strain FJLY). Strain SVA-FJLY isolated from a farm in Fujian Province was used as focus of study. Five pairs of primers were designed based on whole-genome sequence of SVV-001 (GenBank No. DQ641257.1) and whole-genome sequence of strain SVA-FJLY was obtained and analyzed by RT-PCR, sequencing, and splicing. Piglets aged 3-4 weeks old were also infected with this strain by intranasal spray. Results showed that genome of strain SVA-FJLY had a full length of 7 275 bp (excluding PolyA). It encoded a polyprotein, VP1 protein, and VP2 protein. Strain SVA-FJLY had high homology with reference strain and HeB01-2017 strain (MF967574.1), with highest homology reaching 98.5%, while it had low homology with SVA prototype strain SVV-001 (DQ641257.1), reaching 93.9%. Strain SVA-FJLY belonged to the same branch as several Senecavirus A strains isolated in China, and domestically had closest relationship with strain HeB01-2017, while regarding foreign strains it had closest relationship with Colombia-2016 (KX857728.1). Animal experiments showed that two of three animals in experimental group suffered from the disease, while all three animals in control group remained normal. All six piglets survived 10 days after challenge of experimental group. Whole-genome sequence of strain SVA-FJLY was obtained by genome sequencing. Genomic characteristics of strain SVA-FJLY and its homology with other strains were clarified. Pathogenicity of strain SVA-FJLY was also revealed. Moreover, a reference for reverse genetics and vaccine development for SVA was provided, and database with genome information on SVA was also enriched.