MOLECULAR ANALYSIS OF INFLUENZA VIRUS A/H1N1 NON-STRUCTURAL GENE ISOLATED FROM IRANIAN PATIENTS WITH SEVERE SYMPTOMS

Background and Aim:Influenza A viruses are responsible for annual epidemics and occasional pandemics. The eighth segment of the viral genome coded for non-structural (NS) proteins is one of the known virulence determinants of virus. In this study we investigate the characterization and variability of the NS gene recovered from high pathogen H1N1 influenza viruses isolated from Iranian patients.Methods:Nasopharyngeal swabs collected from outpatients with clinical symptoms were subjected for influenza detection and subtyping using real-time PCR. Positive specimens with high viral load underwent virus amplification on cell culture. The NS segments were amplified and sequenced from four 2015 samples from patients with severe symptoms and eight 2017 samples randomly selected. Genetic characterization, phylogenetic and protein modeling analysis carried on the obtained data with those of other full-length sequences from other geographic regions available in GenBank using MEGA7,ModWeb,Modfold softwares.Results:Phylogenetic analysis on the NS gene of A/H1N1 isolates revealed that the Iranian strains were close to strains of A/Egypt/42/2014, A/Saudi Arabia/22/2015 and A/Ankara/WRAIR1425T/2009. The molecular analysis of these sequences also identified 5 mutations. Three-dimensional structure of Iranian NS proteins compared with those from reference genes available in GeneBank showed no significant deviation in functional domain.Conclusion:The high similarity of Iranian NS gene with those from Middle-eastern countries, may indicate that they all derived from the same origin. None of the observed mutations implied the severity of symptoms so molecular analysis of other alleles is needed to explain the high pathogenic feature of those isolates.

کلیدواژه ها:

Influenza A(H1N1) ، NS ، Phylogenetic