College of Life Sciences of Longyan University, Longyan, Fujian Province 364012, China; Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Fujian Province 364012, China.
College of Life Sciences of Longyan University, Longyan, Fujian Province 364012, China; Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Fujian Province 364012, China.
Infect Genet Evol. 2019 Mar;68:119-126. doi: 10.1016/j.meegid.2018.12.006. Epub 2018 Dec 5.
Porcine reproductive and respiratory syndrome (PRRS) is one of the most important viral swine diseases, resulting in immense economic losses in Chinese pig industry. Currently, four major lineages: lineage 1 (NADC30-like), 3 (QYYZ-like), 5.1 (VR2332-like) and 8.7 (JXA1-like) of type 2 PRRSV (North American type) have been circulating in China based on classification system, which have caused concern about the potential of virus recombination. In the present study, a novel variant of PRRSV strain named FJLIUY-2017 was isolated from abortion rate (25%) in pregnant gilts in Fujian Province in China in 2017. To further our knowledge about the novel virus strain, we characterized the complete genome of FJLIUY-2017. Comparison to PRRS sequences in GenBank confirmed the absence of close relatives (<92%), but indicated FJLIUY-2017 belonged to NADC30-like PRRSV. The full length of FJLIUY-2017 was determined to be 15017 nucleotides (nt), excluding the poly(A) tail, shared 86.2-86.6% identity with JXA1-like strains (JXA1, TJ and FJYR), 88.9-90.6% with NADC30-like PRRSVs (NADC30, FJZ03 and CHsx1401), 86.4-86.5% with VR2332-like (VR2332, RespPRRS MLV and BJ-4) and only 60.8% with LV (European type). Recombination analyses revealed genomic breakpoints in structural (ORF3, ORF4 and ORF7) and nonstructural (Nsp1, Nsp2, Nsp6, Nsp9, Nsp11 and Nsp12) regions of the genomes with evidence for recombination events between lineages 1, 3, 5.1 and 8.7. Taken altogether, the results of our study provide further confirmation that PRRSV is prone to undergo recombination events. Thus, it is critical to monitor PRRSV evolution in China and establish an effective strategy for the control of PRRS.
猪繁殖与呼吸综合征（PRRS）是最重要的病毒性猪病之一，给中国的养猪业造成了巨大的经济损失。目前，根据分类系统，在中国流行的 2 型 PRRSV（北美型）有 4 个主要谱系：谱系 1（NADC30 样）、3（QYYZ 样）、5.1（VR2332 样）和 8.7（JXA1 样），这引起了人们对病毒重组潜在可能性的关注。本研究从 2017 年中国福建省流产率（25%）的妊娠母猪中分离到一株新的 PRRSV 变异株，命名为 FJLIUY-2017。为了进一步了解该新型病毒株，我们对 FJLIUY-2017 的全基因组进行了特征描述。与 GenBank 中的 PRRS 序列比较证实，它与亲缘关系较近的病毒（<92%）不存在密切关系，但表明 FJLIUY-2017 属于 NADC30 样 PRRSV。FJLIUY-2017 的全长为 15017 个核苷酸（nt），不包括 poly(A)尾，与 JXA1 样株（JXA1、TJ 和 FJYR）的同源性为 86.2-86.6%，与 NADC30 样 PRRSV（NADC30、FJZ03 和 CHsx1401）的同源性为 88.9-90.6%，与 VR2332 样（VR2332、RespPRRS MLV 和 BJ-4）的同源性为 86.4-86.5%，与 LV（欧洲型）的同源性仅为 60.8%。重组分析显示，基因组结构（ORF3、ORF4 和 ORF7）和非结构（Nsp1、Nsp2、Nsp6、Nsp9、Nsp11 和 Nsp12）区的基因组存在基因断裂点，有证据表明谱系 1、3、5.1 和 8.7 之间发生了重组事件。总之，本研究结果进一步证实了 PRRSV 容易发生重组事件。因此，监测中国 PRRSV 的进化并建立有效的 PRRS 控制策略至关重要。
