Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (1): 235-246.DOI: 10.1016/j.jia.2024.03.056

• • 上一篇    下一篇

中国类NADC30和类NADC34 PRRSV新特征:L1A变异株的流行和致病性分析

  

  • 收稿日期:2023-12-01 修回日期:2024-03-16 接受日期:2024-02-15 出版日期:2026-01-20 发布日期:2025-12-09

Novel characterization of NADC30-like and NADC34-like PRRSV strains in China: epidemiological status and pathogenicity analysis of L1A variants

Hu Xu1*, Siyu Zhang1*, Zhenyang Guo1*, Chao Li1, Bangjun Gong1, Jinhao Li1, Qi Sun1, Jing Zhao1, Menglin Zhang1, Lirun Xiang1, Yandong Tang1, Chaoliang Leng2, Jianan Wu1, Qian Wang1, Jinmei Peng1, Guohui Zhou1, Huairan Liu1, Tongqing An1, Xuehui Cai1, Zhijun Tian1#, Hongliang Zhang1#   

  1. 1 State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China

    2 Henan Provincial Engineering and Technology Center of Animal Disease Diagnosis and Integrated Control, Nanyang Normal University, Nanyang 473061, China

  • Received:2023-12-01 Revised:2024-03-16 Accepted:2024-02-15 Online:2026-01-20 Published:2025-12-09
  • About author:Hu Xu, E-mail: xuhu1995@foxmail.com; Siyu Zhang, E-mail: zhangsiyucaas@163.com; #Correspondence Zhijun Tian, E-mail: tianzhijun@caas.com; Hongliang Zhang, E-mail: zhanghongliang01@caas.cn * These authors contributed equally to this work.
  • Supported by:
    This study was supported by grants from the National Natural Science Foundation of China (32172890 and 32002315), the National Key Research and Development Program of China (2022YFF0711004), the Natural Science Foundation of Heilongjiang Province, China (YQ2022C042), the State Key Laboratory of Veterinary Biotechnology Foundation of China (SKLVBF202208), the Postdoctoral Fellowship Program of CPSF, China (GZC20233062) and the National Center of Technology Innovation for Pigs, China (NCTIP-XD/C09).

摘要:

近年来Lineage1 PRRSV已成为全球流行范围最广,遗传多样性最为复杂的谱系。中国流行的Lineage1毒株由L1A(类NADC34)和L1C(类NADC30)组成。本研究发现我国Lineage1 PRRSV演化出一个新的独立分支,它们具有一致的缺失和重组特征,将其命名为L1A变异株。随后全面分析了L1A变异株的系统发育、流行现状和致病性。ORF5基因系统发育分析结果显示L1A变异株属于类NADC34 PRRSV(L1A亚型)。所有L1A变异株在Nsp2区均存在131氨基酸的不连续缺失(与NADC30株相同)。重组分析表明,L1A变异株是一种以类NADC30 PRRSV为骨架,类高致病性PRRSV提供部分非结构蛋白基因区域、类NADC34 PRRSV提供ORF2~ORF6区域的重组病毒。本研究利用PAM和Marc-145细胞成功分离了L1A变异株TZJ2756,在致病性实验中,TZJ2756株对仔猪展现出中等致病性。引起感染仔猪出现明显的临床症状,包括持续发烧和体重增长明显减缓,并引起长时间高载量的病毒血症。组织病理学检测发现攻毒组猪只出现肺间质性水肿和严重的间质性肺炎。目前L1A变异株已在中国至少12个省份检出,并且与美国流行的L1C变异株具有诸多相似的流行特征,加强对该类毒株的检测已迫在眉睫。本研究聚焦新发Lineage1 PRRSV流行特征,首次报道了L1A变异株出现流行及其致病性,为我国PRRSV防控提供了重要数据。

Abstract:

NADC34-like porcine reproductive and respiratory syndrome virus (PRRSV), which first appeared in China in 2017, is currently one of the main epidemic strains in China.  In this study, we found that a new variant of NADC34-like PRRSV evolved, named the L1A variant.  The phylogenetics, epidemic status, and pathogenicity of the LA variants were subsequently comprehensively evaluated.  Based on the results of the ORF5 phylogenetic analysis, the L1A variants were classified as NADC34-like PPRSV.  All the strains had the same discontinuous 131-aa deletion in the NSP2 region (similar to that in the NADC30).  Recombination analysis revealed that the L1A variants were recombinant viruses that contained an NADC30-like PRRSV skeleton, a nonstructural protein-encoding gene region obtained in part from JXA1-like PRRSV and a ORF2-ORF6 gene region partly obtained from NADC34-like PRRSV and that exhibited similar recombination patterns.  We successfully isolated the L1A variant TZJ2756 from PAMs and Marc-145 cells.  In animal experiments, TZJ2756 exhibited moderate pathogenicity in piglets, causing obvious clinical symptoms, namely, persistent fever, significantly reduced body weight, interstitial edema and severe interstitial pneumonia in the lungs, and prolonged high-load viremia.  L1A variants have been detected in at least 12 provinces in China and share many similar epidemiological characteristics with the American L1C variant.  This research will enhance our understanding of the prevalence of L1A variants and furnish valuable data for the ongoing monitoring of NADC34-like PRRSV in China.

Key words: NADC34-like porcine reproductive and respiratory syndrome virus (PRRSV) , NADC30-like PRRSV ,  L1A variant ,  recombination ,  pathogenicity