Adaptive Mutations in Nuclear Export Protein and Non-Structural 1 Protein of Avian Influenza a H9N2 Virus Circulating in Punjab, Pakistan

Avian influenza A virus subtype H9N2 has been in circulation since last two decades in poultry flocks of Pakistan. It is causing immense economic losses to the farmers. Avian influenza H9N2 virus were isolated from infected birds of different poultry farms in the Province of Punjab, Pakistan. Segment eight gene of the virus was amplified using RT-PCR and sequenced to analyze mutations in this viral segment. Phylogenetic tree analysis showed sequences from 2015 to 2017 form a single evolving clade. Valdar residues conservation scores by multiple sequence alignment showed the C terminal region of NEP protein is conserved while C terminal region of effector domain (ED) of NSI protein exhibit mutations. These mutations are enhancing the total hydrophobicity of the molecules. Hydrophobicity was calculated by using Kyte and Doolittle method. High hydrophobicity of NS1 protein is also posing a potential for H9N2 virus to adapt in host, which might be contributing to the increase in pathogenicity of the circulating H9N2 virus.