Assessment of influenza A (H1N1, H3N2) oseltamivir resistance during 2017-2019 in Iran

Amytis Gholami; Nazanin Zahra Shafiei-Jandaghi; Nastaran Ghavami; Forough Tavakoli; Jila Yavarian; Talat Mokhtari-Azad

doi:10.18502/ijm.v14i4.10241

Amytis Gholami Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Nazanin Zahra Shafiei-Jandaghi Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Nastaran Ghavami Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Forough Tavakoli Department of Bacteriology and Virology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
Jila Yavarian Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Talat Mokhtari-Azad Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/ijm.v14i4.10241

Keywords: Influenza A viruses; Neuraminidase; Oseltamivir; Antiviral drug; Iran

Abstract

Background and Objectives: Neuraminidase inhibitors (NAIs) as an imperative antiviral for influenza prophylaxis and treatment are being consumed worldwide. Increasing use of these antivirals might be associated with drug resistance. Re- garding the significance of these variations, this study aimed to investigate the mutations occurring in the NA gene of influ- enza A viruses leading to oseltamivir resistance during 2017-2019 in Iran.

Materials and Methods: In this cross-sectional study, 40 influenza A (H1N1, H3N2) strains, isolated in National Influenza Center (NIC) from patients with Severe Acute Respiratory Infection (SARI) during 2017-2019 were subjected to RT-PCR and sequencing of NA complete gene. The frequency of oseltamivir resistance and variation of NA amino acids in these strains were investigated.

Results: No significant mutation conferring oseltamivir resistance was detected. However, NA antigenic sites in these strains depicted minor changes compared to the vaccine strains. Among H3N2 isolates, mutations at 329, 344, 346 and 385 and among H1N1 isolates mutations at 143 and 188 residues occurred in NA antigenic regions.

Conclusion: Evaluation of NA gene sequences, showed no resistant viruses to oseltamivir. Given that the viruses in the pres- ent study were the last viruses circulating in Iran before COVID-19 pandemic, the results will be beneficial to have a worthy comparison with the strains circulating after the pandemic. Constant monitoring for the emergence of drug-resistant variants and antigenic changes are crucial for all countries.