2018—2019年山东地区猪繁殖与呼吸综合征病毒分子流行病学调查

Molecular Epidemiological Investigation of Porcine Reproductive and Respiratory Syndrome Virus in Shandong Province from 2018 to 2019

为了解近年来山东地区猪繁殖与呼吸综合征病毒(PRRSV)的流行及分子遗传变异情况。对2018—2019年山东不同地区493份疑似PRRSV样品进行RT-PCR检测,并对34份PRRSV阳性样品进行ORF 5基因核苷酸及GP5蛋白氨基酸序列分析比较。结果显示,2018年和2019年送检样品中PRRSV抗原阳性率分别为20.79%和24.09%;同源性对比及遗传进化分析,34株PRRSV主要属于谱系1和谱系8,且2018年和2019年均为谱系1中的PRRSV检出率最高,分别为50.00%和59.10%;氨基酸分析显示,34株PRRSV主要以点突变为主,未见插入突变,与不同谱系代表毒株相比,诱饵表位、中和表位、潜在毒力位点及N-糖基化位点均存在不同程度的变异。结果表明,NADC 30 like PRRSV可能已成为山东地区优势野毒毒株,且仍在不断发生变异。

To confirm the prevalence and molecular genetic variation of porcine reproductive and respiratory syndrome virus(PRRSV)in Shandong province in recent years.We used RT-PCR to detect PRRSV in 493 suspected samples from different regions of Shandong province from 2018 to 2019.The nucleotide sequence of ORF5 gene and amino acid sequence of GP5 protein were analyzed and compared in 34 PRRSV positive samples.The results showed that the positive rate of PRRSV in 2018 and 2019 were 20.79%and 24.09%,respectively.Homology comparison and genetic evolution analysis showed that 34 PRRSV isolates mainly belonged to lineage 1 and lineage 8,and the positive rate of PRRSV in lineage 1 was the highest in 2018 and 2019,which were 50.00%and 59.10%,respectively.Amino acid analysis showed that point mutation was dominant in the 34 PRRSV isolates,and no insertion mutation was observed.Compared with the representative strains of different lineages,there were variations in the bait epitopes,neutralization epitopes,potential virulence sites and N-glycosylation sites.Therefore,we speculate that NADC 30 like PRRSV strain may have become the dominant wild virus strain in Shandong province,and the PRRSV wild strains are in the constant mutation.