非洲猪瘟病毒JX21毒株全基因组序列分析和生物学特性研究

Complete genome sequence analysis and biological characteristics study of African swine fever virus JX21 strain

为了明确非洲猪瘟病毒(African swine fever virus,ASFV)JX21毒株的基因组变化及其生物学特性,试验采用PCR检测、病毒分离培养、病毒全基因组测序、红细胞吸附试验及动物感染试验等对从江西省某菜市场采样分离到的ASFV自然变异毒株JX21进行研究。结果表明:与ASFV SY18毒株序列比较,JX21毒株全基因组序列中出现110处碱基差异和8个基因的自然缺失。其中EP402R基因(编码CD2v蛋白)第395位碱基后插入1个碱基“A”,导致翻译提前终止,JX21毒株丧失了红细胞吸附特性。试验组5头健康家猪感染JX21毒株后,28 d内全部死亡,期间均出现较高水平的病毒血症,剖检后均出现ASFV阳性组织,病程较长。说明分离的JX21毒株属于自然变异株,基因组中存在多处变异,其中EP402R基因变异可引起病毒失去红细胞吸附特性,其毒力未见明显减弱,仍为100%致死,但病程延长。

In order to clarify the genome changes of African swine fever virus(ASFV)JX21 strain and to explore the biological characteristics of ASFV JX21 strain,PCR detection,virus isolation and culture,virus whole genome sequencing,hemadsorption and animal infection test were used to study the natural variation of ASFV JX21 strain which was actively sampled and isolated from a food market in Jiangxi Province.The results showed that compared with the sequence of ASFV SY18,there were 110 base differences and 8 natural deletions in the whole genome of JX21 strain.One base“A”was inserted after the 395th base of EP402R gene(CD2v),resulting in early termination of translation,and JX21 strain lost hemadsorption.In the animal infection test,all 5 healthy pigs in the experimental group died within 28 days after being infected with JX21 strain.During the period,high level of viremia was found and the disease course was long.5 pigs showed positive tissue of ASFV after autopsy.This indicated that the isolated JX21 strain belonged to natural mutation,and there were many mutations in the genome,among which EP402R gene mutation could cause the virus to lose the RBC adsorption property,and its virulence was not significantly weakened,with 100%of fatality rate,but the onset time was prolonged.