Isolation of influenza viruses from wild birds in the Volga River basin and in the North Caspian Region

摘要: Abstract Background: The North Caspian Region and delta of the Volga River constitute historic flyways a place mass congregation wild birds for most year. Methods: A total 3513 biological samples from 3229 37 species were collected, antigenic structure receptor activity isolated influenza viruses studied. Nucleotide sequences NS gene PCR fragments analysed. Results: 344 strains virus with various combination hemagglutinin neuraminidase isolated: H4N3, H4N6, H5N2, H6N2, H9N2, H13N3, H13N6, H13N8, H14N5, H14N6. A/H13 was annually nestlings Larus ichthyaetus L. argentatus species. Isolation embryos young suggests existence at least two ways infection: alimentary transovarial. studies binding H13 H14 gangliosides GM3, GD1a 3SPG did not reveal essential difference H1–H12 subtypes. Among avian HA only HA13 subtype has substitution residue 77 DT, 228 GS. 225 GN found in HA14 also Sea. Study genes some isolates revealed significant differences same time but birds. Conclusions: ability H5, H4, H6, H9 to infect mammals provoke epizootics determine necessity carry out further monitoring Northern basin other key points Eurasia.