Study on the genomic sequences and molecular characteristics of influenza A(H1N1) virus

Abstract

Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current human seasonal influenzavaccines confered little protection against influenza A/H1N1 because of the great diversity on antigenic domains between A/H1N1 virus and vaccine virus. Conclusions Influenza A(H1N1) virus is a reassortant virus of North America and Eurasia hneages swine influenza virus. It is important to develop a vaccine against the currently circulating virus strain to control the disease spread. Key words: Influenza virus; H1N1 subtype; Molecular characteristics