为分析研究天津地区猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)的分子遗传进化关系,对2019-2022年收集的20份天津地区PRRSV阳性样品进行ORF5克隆测序,以开展遗传变异研究和系统发育分析.遗传进化结果显示,20株毒株有11株属于谱系1.8,3株属于谱系1.5,5株属于谱系8,1株为谱系5,表明该地区PRRSV毒株流行呈现多样性.ORF5基因及推导氨基酸同源性和位点进行分析,其中11株谱系1.8毒株与NADC30毒株核苷酸同源性为91.2％～93.0％,氨基酸同源性为89.6％～93.5％;3株1.5谱系毒株与NADC34毒株核苷酸同源性为93.4％～96.5％,氨基酸同源性为92.5％～95.5％;4株分离株与HP-PRRSV毒株同源性最高,核苷酸同源性为90.0％～95.5％,氨基酸同源性为86.6％～91.0％;1株分离株与经典毒株CH-1a同源性最高,核苷酸和氨基酸同源性分别为90.0％和89.1％,1株谱系5毒株与VR2332毒株核苷酸和氨基酸同源性分别为97.8％和96.0％.在关键的氨基酸位点上存在一定程度突变,这些关键突变很可能造成病毒致病力差异,并导致病毒逃逸发生.本研究对天津地区PRRS防控提供数据支持.
Genetic evolution analysis of the ORF5 gene in porcine reproductive and respiratory syndrome virus in Tianjin from 2019 to 2022
In order to analyze the molecular genetic evolution of Porcine reproductive and respiratory syndrome virus(PRRSV)in Tianjin from 2019 to 2022,ORF5 sequencing was performed on twenty PRRSV positive samples to carry out genetic variation research and phylogenetic analysis.The results showed that eleven of the twenty strains belonged to lineage 1.8,three strains belonged to lineage 1.5,five strains belonged to lineage 8,and one strain belonged to lineage 5,indicating that the prevalence of PRRSV strains showed diversity.Subsequently,the ORF5 gene and GP5 protein homology and amino acid sites were analyzed,and the comparison results with the reference strains of each lineage showed that the nucleotide homology between the 1.8 strain of the eleven lineage and the NADC30 strain was 91.2％～93.0％,and the amino acid homology was 89.6％～93.5％.The nucleotide homology between the three 1.5 lineage strains and the NADC34 strain was 93.4％～96.5％,and the amino acid homology was 92.5％～95.5％.The four isolates had the highest homology with HP-PRRSV strains,with nucleotide homology of 90.0％～95.5％and amino acid homology of 86.6％～91.0％.One isolate had the highest homology to the classical strain CH-1a,with nucleotide and amino acid homology of 90.0％and 89.1％,respectively,and the nucleotide and amino acid homology of one lineage 5 strain and VR2332 strain were 97.8％and 96.0％,respectively.Some key mutations were found and were likely to cause differences in viral virulence and lead to viral escape.This study may provide data supporting for the prevention and control of PRRS in Tianjin.
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万方数据
