ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 14 (3), pp. 001-008, March, 2020. © International Scholars Journals
Full Length Research Paper
Molecular characterization and phylogenetic analysis of neuraminidase gene of avian Influenza H9N2 viruses isolated from commercial broiler chicken in Iran
S. Vatandour1*, M. Bozorgmehrifard2, H. Shoushtari3, S. Charkhkar4 and S. Bakhtiari5
1Department of Poultry Disease,Science and Research Branch, Islamic Azad University, Tehran, Iran.
2Division of Avian Disease, Tehran University, Iran.
3Division of Avian Disease and Research, Razi Vaccine and Serum Research Institute, Karaj, Tehran, Iran.
4Division of Avian Disease, Islamic Azad University, Science and Research Branch, Tehran, Iran.
5Iran Veterinary Organization, Tehran General Office, Tehran, Iran.
Accepted 18 September, 2019
Abstract
Avian influenza (AI) outbreaks due to H9N2 subtype of avian influenza virus (AIV) occurred in poultry industry in Iran, throughout the past decade and caused serious economic losses as a result of decreased egg production, increased mortality and the cost of vaccination in Iranian poultry industry. Our aim was to find the phylogenic and genetic relationships among avian influenza viruses recently isolated from poultry in Iran with other Asian H9N2 lineages (1998-2007). The complete nucleotide sequences of the neuraminidase (NA) genes of ten H9N2 influenza virus strain isolated from diseased chickens in different farms in Iran during 1998-2007, were amplified and sequenced and phylogenetic relationships between these and previously reported N2 genes were investigated. The viruses surface glycoprotein genes was >90% similar to those of A/Quail/Hongkong/G1/97 (H9N2) lineage. The NA stalks regions in these viruses had no deletion or insertion or shortening as compared to that A/DK/HK/Y280/97 lineage (CK/Bei-like viruses) and the 2 human isolates A/HK/1073/99, A/HK/1074/99. The hemadsorbing site of NA had up to 3 amino acid substitution and is different from those of earlier Iranian viruses and ten Iranian isolates possessed seven potential glycosylation sites like the most H9N2 isolates. Phylogenetic analysis of NA gene showed that they belonged to the same A/Quail/Hong Kong/G1/97 like virus sub lineage.
Key words: Avian influenza virus, A/Quail/Hongkong/G1/97 (H9N2), neuraminidase gene, phylogenetic analysis, Iran.