Genetic variability of isolates of pandemic influenza virus A H1N1 isolated in Russia in 2009

In 14 isolates of pandemic influenza virus A H1N1 extracted from patients with influenza in 2009, complete nucleotide sequences of genome segments encoding surface proteins hemagglutinin and neuraminidase were determined. Phylogenetic analysis of these sequences showed their genetic similarity with the corresponding genes of other isolates of pandemic influenza virus A (H1N1) 2009 extracted in other countries, and the degree of homology for each gene was over 99%. Neuraminidase mutations known in the literature that lead to the stability of the virus to oseltamivir and other drugs of neuraminidase inhibitors were not recorded in the studied isolates. In four isolates from autopsy material, G155E mutation was found in hemagglutinin of the isolate A/Salekhard/01/2009 (H1N1). This mutation leads to increased viral replication in developing chick embryos. The frequency and nature of the nucleotide substitutions in the hemagglutinin and neuraminidase genes are determined.