Genetic diversity and recombination analysis of NADC34-like porcine reproductive and respiratory syndrome viruses
image: Classification of NADC34-like PRRSVs based on phylogenetic analysis and recombination patterns
Credit: Zhengqin Ye, Wenqiang Wang, Zhenbang Zhu, Wei Wen, Hu Suk Lee, Xiangdong Li
Porcine reproductive and respiratory syndrome virus (PRRSV) causes porcine reproductive and respiratory syndrome (PRRS), resulting in substantial economic losses to the global swine industry. Previous studies have characterized recombination events in specific PRRSV strains, such as highly pathogenic PRRSV (HP-PRRSV) and NADC30-like viruses within China. NADC34-like PRRS viruses have gained attention due to their widespread prevalence and variable pathogenicity. The pathogenicity of NADC34-like PRRSV strains varies, ranging from high to low, causing substantial economic losses to the swine industry.
To address the problem, a team of researchers from China and South Korea classified 176 NADC34-like PRRSV strains by updating the phylogenetic classification of PRRSV based on 1,598 whole-genome sequences retrieved from the GenBank database in June 2025. They then defined 12 consistent recombinant patterns (R1-R12) across the 176 NADC34-like whole-genome sequences. Their findings are published in the Journal of Integrative Agriculture.
“Among the 176 strains, 142 were from the USA, 30 from China, and 4 from South Korea,” explains corresponding author Prof. Xiangdong Li from Yangzhou University, China. “Additionally, we determined 100 recombinant strains using RDP4 with 7 algorithms (RDP, GENECONV, BootScan, MaxChi, Chimaera, SiSscan, and 3Seq) verified by SimPlot software.”
Whole-genome analysis revealed significant genetic diversity and recombination patterns among NADC34-like PRRSV strains in the USA, China, and South Korea. “Distinct from previous studies that focused solely on the USA or China, this study provides a comparative international analysis,” says Li. “Through that, we identified a temporal shift in recombination hotspots in Chinese strains (from structural proteins to ORF1a), contrasting with the persistent circulation of the NADC34-R1 recombinant lineage in the USA.”
The researchers noted that continued surveillance and in-depth analysis are crucial for developing targeted intervention and control strategies, providing valuable insights for future PRRSV prevention.
Contact the Authors: Zhengqin Ye, E-mail: yezhengqin@126.com; Wenqiang Wang, E-mail: wqwang@yzu.edu.cn; Zhenbang Zhu, E-mail: 007583@yzu.edu.cn; Wei Wen, E-mail: 008634@yzu.edu.cn; Hu Suk Lee, E-mail: hs.lee@cnu.ac.kr; #Correspondence Xiangdong Li, E-mail: 007352@yzu.edu.cn
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