Abstract: In this study, total RNA was extracted from tissues and serum in incident swines from different regions of Shanxi. The highly pathogenic PRRSV of 16 samples were positive by RT-PCR. The gene sequence of Nsp2 was amplified using the specific primers. The analysis of gene sequences by DNAStar and bioinfomatic software showed that the amino acids sequence of Nsp2 shared 69.8% to 71.7%, 85.3% to 87.9%, 68.7% to 70.6%, 91.7% to 94.3%, 94.3% to 98.5%, 95.1% to 98.9% similarity with VR-2332, CH-1a, BJ-4, HB-1, HuN4 and JXA1 strains respectively, following the comparison of sequences and homologue analysis. The results also showed that Nsp2 from Shanxi strains lacked amino acids at 2 locations, and one location was 1 amino acid and another was continuous 29 amino acids. It suggested that the PRRSV mutant strains in Shanxi belonged to the same branch as the domestic epidemic strains.

Key words: PRRSV; isolation and identification; Nsp2 gene; sequence analysis