M Malekan - Department of Technical Services, SAVAPARS (Ceva Sante Animale Exlusive Distributor in Iran), Tehran, Iran
M Vasfimarandi - Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
MM Ranjbar - Razi Vaccine & Serum Research Institute, Agricultural Research, Education & Extension Organization, Karaj, Iran
AR Homayounimehr - Department of Technical Services, SAVAPARS (Ceva Sante Animale Exlusive Distributor in Iran), Tehran, Iran

Objectives:Avian Influenza viruses are belonged to subtype H۹N۲ of type A of Influenza viruses. H۹N۲ Subtype was isolated at ۱۹۹۸ in Iran and since then, several outbreaks in Iranian poultry flocks has been reported. Avian influenza affects performance of poultry flocks and may cause highmortalities and heavy economic losses.There are two groups of drugs which are effective on influenza viruses, first group is M۲ blocker drugs and second group is NA inhibitors.Continuous usage of these drugs may cause resistance. The main goal of current study is to evaluate mutationswhich are responsible to resistance against NA inhibitor drugs.Material and Methods:۱۰۰ specimens from ۱۵ flocks collected during ۲۰۱۲ and ۲۰۱۳. Each specimen prepared and cultured in ۹ days old chicken embryo. After ۵ days allantoic fluid was collected and used for haemagglutination test. H۹N۲ subtype was confirmed by specific RT-PCR of H۹ and N۲. Specific RT-PCR was conducted for M, HA and NA genes of confirmed viruses. Then PCR products were used for sequencing. Bioinformaticsoftwares were used for analysis.Results and Conclusion:۶ isolates were belonged to ۲۰۱۳ and ۵ were belonged to ۲۰۱۲. None of the isolates had Na inhibitor resistance mutations.

Poultry, Influenza, H۹N۲, NA inhibitors, RT-PCR