Su Zhiying, Wang Xindong, Liu Keyi, Chen Guochang, Zhang Kang, Liu Jiaqi, Pang Yanli, Ren Tongwei, Qin Yifeng, Ouyang Kang, Yin Yeshi, Chen Ying, Huang Weijian, Wei Zuzhang
Laboratory of Animal infectious Diseases and molecular Immunology, College of Animal Science and Technology, Guangxi University, 530005, Nanning, China.
Laboratory of Animal infectious Diseases and molecular Immunology, College of Animal Science and Technology, Guangxi University, 530005, Nanning, China; Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, 530005, Nanning, China; Guangxi Key Laboratory of Animal Breeding and Disease Control and Prevention, 530005, Nanning, China.
Microb Pathog. 2025 Mar;200:107351. doi: 10.1016/j.micpath.2025.107351. Epub 2025 Jan 30.
Since 2010, the Lineage 1 (NADC30-like) and Lineage 3 (QYYZ-like) strains of PRRSV-2 have become widespread in China, undergoing recombination and resulting in varying virulent and immune-evading mutants that have severely impacted the pig farming industry. In this study, we isolated one NADC30-like strain (GXHX20211106) and one QYYZ-like strain (GXGG202007) from pig serum samples collected in southern China. Comparative genomic analysis revealed that GXHX20211106 shares 90 % identity with NADC30, while GXGG202007 shows 91.4 % similarity to QYYZ. Both strains exhibit characteristic amino acids deletions or insertions in the Nsp2 region. Phylogenetic analyses further classified GXHX20211106 within Lineage 1.8 (NADC30-like) and GXGG202007 in Lineage 3 (QYYZ-like). Recombination analysis demonstrated that GXHX20211106 resulted from recombination between NADC30-like and HP-PRRSV-like strains, while GXGG202007 originated from recombination events involving QYYZ-like, VR-2332-like, and HP-PRRSV-like strains. Pathogenicity studies in piglets indicated that both isolates caused moderate clinical signs, with GXHX20211106 showing higher virulence compared to GXGG202007. No deaths were recorded in the infected piglets. These findings highlight the critical role of recombination in shaping PRRSV virulence and underscore the need for ongoing surveillance and control measures to mitigate the impact of recombinant PRRSV strains in southern China.
自2010年以来，猪繁殖与呼吸综合征病毒2型（PRRSV-2）的1型（类NADC30）和3型（类QYYZ）毒株在中国广泛传播，发生重组并产生了各种具有不同毒力和免疫逃避能力的突变体，对养猪业造成了严重影响。在本研究中，我们从中国南方采集的猪血清样本中分离出一株类NADC30毒株（GXHX20211106）和一株类QYYZ毒株（GXGG202007）。比较基因组分析显示，GXHX20211106与NADC30的同一性为90%，而GXGG202007与QYYZ的相似性为91.4%。两株毒株在非结构蛋白2（Nsp2）区域均表现出特征性的氨基酸缺失或插入。系统发育分析进一步将GXHX20211106归类为1.8型（类NADC30），将GXGG202007归类为3型（类QYYZ）。重组分析表明，GXHX20211106是由类NADC30毒株和高致病性PRRSV（HP-PRRSV）毒株之间的重组产生的，而GXGG202007则源自涉及类QYYZ、VR-2332和HP-PRRSV毒株的重组事件。仔猪致病性研究表明，两株分离株均引起中度临床症状，与GXGG202007相比，GXHX20211106的毒力更高。感染仔猪未记录到死亡情况。这些发现突出了重组在塑造PRRSV毒力方面的关键作用，并强调需要持续监测和采取控制措施，以减轻重组PRRSV毒株在中国南方的影响。
