Molecular-genetic analysis of epidemical strains of influenza a virus based on the neuraminidase and M2 protein gene sequence

The results of a molecular-genetic analysis of epidemical strains of influenza A virus isolated in Russia from 1995 to 2007 are described. The analysis based on the genes sequences of neuraminidase (NA) and M2 protein of influenza A virus was performed. 15 strains of subtype A(H3N2) and 17 strains of subtype A(H1N1) were analyzed for the detection of mutations in the genome virus. The analysis of amino acid sequences of M2 protein of the all remantadin resistant strains demonstrated the substitution S31N as the basic resistant marker. Additional mutations in M2 and NA proteins were detected for both subtypes of the virus. Identified mutations, together with an S31N substitution, could be classified as novel markers for identification of remantadin-resistant strains. The sequence’s analysis of NA from both subtypes of the influenza virus possessed no known mutations to cause a resistance to neuraminidase inhibitors, which indicates the susceptibility of analyzed strains to NA inhibitors.