Objective: Complete S and M segments of two Seoul virus (SEOV) strains were obtained to determine their genetic types and characteristics.
Methods: The complete S and M segments from the isolate Li and lung tissue (sample LF18) were amplified by RT-PCR. Genetic analyses were performed by using DNAStar and PHYLIP program package.
Results: Their sequences consisted of 1772 nucleotides, and had an open reading frame (ORF, 43 to 1332 nt) encoding a nucleoprotein of 429 amino acids for both two strains. The complete M segment sequences consisted of 3653 nucleotides and had an ORF encoding a GnGc precursor of 1133 amino acids. The GnGc precursor of the two strains had 62 cysteine and 6 N-glycosylation sites. Both two strains shared a high degree of homology with other known SEOV strains including strains L99, Gou3, and vaccine strain Z37, with 87.6% to 99.2% and 83.6% to 97.3% nucleotide identities, respectively. On the S- and M-trees, the two strains LF18 and Li were grouped into the third cluster of SEOV.
Conclusion: Both LF18 and Li strains belonged to SEOV and shared the congruent genetic characteristics with the vaccine strains Z37. Thus, the bivalent vaccine including the strain Z37 could effectively prevent HFRS which was caused by SEOV in Hebei province.