Isolation and genomic characterization of a Chinese NADC34-like PRRSV isolated from Jiangsu province.

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important causative agents to swine industry, which has been epidemic more than 30 years. The emergence and recombination of new virus strains bring great challenges to the prevention and control of PRRSV. In the present study, we reported and characterized a novel PRRSV strain, designated as JS2021NADC34, which was for the first time isolated from clinical samples in Jiangsu province, China. Phylogenetic analysis demonstrated that JS2021NADC34 belonging to sublineage 1.5 of PRRSV-2 and was highly related to NADC34-like strains. Genetically, JS2021NADC34 strain had a continuous 100 aa depletion in NSP2, as compared to VR-2332 strain, which was consistent with most reported NADC34-like strains. Moreover, there were several amino acid substitutions occurred in the antigenic regions of GP2-GP5. Similar to other reported NADC34-like PRRSV in China, JS2021NADC34 had no recombination with other domestic strains, which indicates this sublineage of PRRSV may be directly transported from the United States and have not undergone extensive mutation and recombination with local strains yet.