2020年河南省猪繁殖与呼吸综合征病毒的分子流行病学调查及ORF5基因变异分析

Molecular Epidemiological Investigation and Genetic Evolution Analysis of ORF5 Gene of Porcine Reproductive and Respiratory Syndrome Virus in Henan Province in 2020

为了解河南省猪繁殖与呼吸综合征病毒(PRRSV)的流行及变异情况,对2020年采集于河南的401份PRRSV感染疑似病料进行TaqMan荧光定量PCR(FQ-PCR)检测。结果显示,共检测出100份阳性样品,阳性率为24.9%。对其中18株PRRSV流行毒株ORF5基因进行测序、同源性比对和遗传进化分析。同源性比对结果显示,18株PRRSV流行毒株ORF5基因核苷酸序列同源性在83.4%以上,与参考毒株同源性为82.9%~99.7%。遗传进化分析结果显示,18株PRRSV流行毒株序列均为美洲株,分属于1、5、8三个谱系,其中2株属于以JXAl为代表的谱系8,1株属于以VR2332为代表的谱系5,15株属于以NADC30为代表的谱系1。氨基酸比对结果显示,HN-TH1-2020、HY-PY1-2020、HN-XY1-2020毒株的13位以及HN-XC1-2020毒株的151位氨基酸毒力相关位点发生了不同程度的突变。

In order to monitor the prevalence and variation of porcine reproductive and respiratory syndrome virus(PRRSV)in Henan Province,a total of 401 clinical samples of porcine reproductive and respiratory syndrome were collected in Henan Province in 2020 and analyzed by TaqMan real-time quantitative PCR(FQ-PCR).The results showed that a total of 100 positive samples were detected,with a positive rate of 24.9%.The ORF5 genes of 18 PRRSV epidemic strains were sequenced for homologous alignment and genetic evolution analysis.Nucleotide homology analysis showed that the ORF5 gene nucleotide homology among 18 strains was above 83.4%,and the nucleotide homology with the reference strain was 82.9%—99.7%.The results of genetic evolution analysis showed that all the 18 PRRSV strains belonged to American genotype,including lineage 1,lineage 5 and lineage 8.Two PRRSV strains belonged to lineage 8 represented by JXAl,one PRRSV strain belonged to lineage 5 represented by VR2332 and 15 PRRSV strains belonged to lineage 1 represented by NADC30.The results of amino acid sequence analysis showed that the 13th amino acid virulence related site of HN-TH1-2020,HY-PY1-2020,HN-XY1-2020 and the 151st amino acid virulence related site of HN-XC1-2020 had different degrees of mutation.