PDF(Pubmed)
Abstract：
Rapid evolution of porcine reproductive and respiratory syndrome virus (PRRSV) is the bottleneck for effective prevention and control of PRRS. Thus, understanding the prevalence and genetic background of PRRSV strains in swine-producing regions is important for disease prevention and control. However, there is only limited information about the epizootiological situation of PRRS in the Xinjiang Uygur Autonomous Region, China. In this study, blood or lung tissue samples were collected from 1,411 PRRS-suspected weaned pigs from 9 pig farms in Changji, Shihezi, and Wujiaqu cities between 2020 and 2022. The samples were first tested by RT-quantitative PCR, yielding a PRRSV-2 positive rate of 53.6%. Subsequently, 36 PRRSV strains were isolated through initial adaptation in bone marrow-derived macrophages followed by propagation in grivet monkey Marc-145 cells. Furthermore, 28 PRRSV-positive samples and 20 cell-adapted viruses were selected for high-throughput sequencing (HTS) to obtain the entire PRRSV genome sequences. Phylogenetic analysis based on the nucleotide sequences of the ORF5 gene of the PRRSV strains identified in this study grouped into sub-lineages 1.8 and 8.7 the former being the dominant strain currently circulating in Xinjiang. However, the NSP2 proteins of the Xinjiang PRRSV strains shared the same deletion patterns as sub-lineage 1.8 prototype strain NADC30 with the exception of 4 strains carrying 2-3 additional amino acid deletions. Further analysis confirmed that recombination events had occurred in 27 of 37 PRRSVs obtained here with the parental strains belonging to sub-lineages 1.8 and 8.7, lineages 3 and 5, with the recombination events having occurred most frequently in the 5\' and 3\' termini of ORF1a and 5\' terminus of ORF1b.
摘要：
猪繁殖与呼吸综合征病毒(PRRSV)的快速进化是PRRS有效防控的瓶颈。因此，了解猪区PRRSV的流行和遗传背景对疾病的预防和控制具有重要意义。然而,关于新疆维吾尔自治区PRRS流行病学情况的信息有限，中国。在这项研究中,从昌吉9个养猪场的1411头疑似PRRS断奶猪中采集血液或肺组织样本，石河子,和五家渠市在2020年至2022年之间。首先用RT-定量PCR对样品进行检测,PRRSV-2阳性率为53.6%。随后，通过在骨髓来源的巨噬细胞中进行初始适应，然后在grivet猴Marc-145细胞中繁殖，分离了36种PRRSV菌株。此外，选择28个PRRSV阳性样品和20个细胞适应性病毒进行高通量测序(HTS)以获得整个PRRSV基因组序列。基于本研究中鉴定的PRRSV毒株ORF5基因核苷酸序列的系统发育分析分为亚谱系1.8和8.7，前者是新疆目前流行的优势菌株。然而,新疆PRRSV毒株的NSP2蛋白与亚谱系1.8原型毒株NADC30具有相同的缺失模式，除了4株携带2-3个额外的氨基酸缺失。进一步的分析证实，此处获得的37个PRRSV中有27个发生了重组事件，其中亲本菌株属于亚谱系1.8和8.7，谱系3和5，重组事件最频繁地发生在5'和3'末端ORF1a和ORF1b的5'末端。
