广西A型塞内卡病毒毒株分离鉴定与致病性分析

Isolation and pathogenicity analysis of Senecavirus A isolates from Guangxi province in China

为明确2株SVA广西分离株的生长特性以及与其他毒株的同源关系,进一步了解其致病性,以GX84/2020和GX94/2020为研究对象,参考GD05/2017(MH316116)毒株全基因组序列设计4对覆盖全长的引物,通过RT-PCR扩增、测序和拼接,得到GX84/2020(MW117128)和GX94/2020(MW117129)毒株的全长基因组序列后进行序列分析;并将其攻毒8~10周龄仔猪。结果表明:GX84/2020和GX94/2020毒株基因组全长7250bp,同源性分析显示这2个广西分离株与其他43株SVA毒株的同源性为93.2%~98.1%;系统发育分析表明GX84/2020和GX94/2020毒株与美国毒株SVA-OH2(KU058183)亲缘关系最近,同源性为98.1%。攻毒结果显示,部分仔猪出现口蹄部位水疱、跛行及体温升高等临床症状,整个过程未出现仔猪死亡。通过全基因组序列分析和动物试验,明确了GX84/2020和GX94/2020分离株的生长特性、与其他毒株的同源关系以及该毒株的致病性,为研发疫苗和抗病毒药物奠定了基础,且丰富了SVA的基因组信息数据库。

The aim of study was to evaluate the growth characteristics,genetic evolution and pathogenicity of two SVA strains isolated from Guangxi province in China.In this study,five pairs of full-length primers were designed according to the complete genome sequence of GD05/2017 Strain.Growth characteristics and sequence analysis was carried out after the complete genome of GX84/2020 and GX94/2020 was obtained by RT-PCR amplification,sequencing and splicing.Meanwhile,piglets aged 8-10 weeks old were also infected with target strains by intramuscular and intranasal injection.The result showed that the complete genome sequences of strains GX84/2020 and GX94/2020 were 7250 nt in length(excluding Poly A).The homology analysis showed that the complete genome sequences of GX84/2020 and GX94/2020 exhibited 93.2%-98.1%identity with the other 43 SVA strains in nucleotide level;phylogenetic analysis also showed that they had higher level of similarity(98.1%)with SVA-OH2 strains from USA.After challenge,some of the piglets in the experimental group had blisters,lameness,high temperature and no death.In all,the complete genome of GX84/2020 and GX94/2020 was obtained by the whole sequencing and analyzed.The growth characteristics,genetic evolution and pathogenicity of GX84/2020 and GX94/2020 strains were identified,which laid foundation for the development of vaccines and antiviral drugs.