Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 48 3 2019 03 12 525 530 Farida BEHZADIAN Research Center for Biosciences and Biotechnology, Malek-Ashtar University, Tehran, Iran Elham MOASSER Research Center for Biosciences and Biotechnology, Malek-Ashtar University, Tehran, Iran Parviz OWLIA Molecular Microbiology Research Center, Shahed University, Tehran, Iran Horieh SADERI Molecular Microbiology Research Center, Shahed University, Tehran, Iran 2019 03 12 Background: A few studies have been done on the molecular analysis of Iranian influenza A isolates M gene. Methods: In 2014, nasal swabs collected from outpatients with clinical symptoms in the hospital clinics of Tehran, Iran were subjected for influenza detection and subtyping using Real-Time RT-PCR. Sequence and phylogenetic analysis performed on four randomly selected isolates from each subtype (H1N1 and H3N2) using neighbor-joining method. Results: Phylogenetic dendrograms drawn based on M nucleotide sequence of H1N1 isolates showed close relatedness with Omanian isolates while the most isolates of H3N2 have clustered with Kuwait isolates and isolates from outside of geographical location. Amino acid sequence analysis showed S31N substitution in all isolates rendering the virus resistant to adamantanes. Conclusion: This study determined the sequence identity and phylogenetic relatedness of M gene sequence got from Iranian influenza A isolates to elucidate the modality of relationship of this gene in comparison with its counterparts from other regions.   https://ijph.tums.ac.ir/index.php/ijph/article/view/16536 https://ijph.tums.ac.ir/index.php/ijph/article/download/16536/6333