RECENT UPDATES ON MOLECULAR DETECTION OF H9N2 AS LOW PATHOGENIC STRAIN OF AVIAN INFLUENZA VIRUS FROM POULTRY FARMS OF LAHORE, PAKISTAN

Abstract

H9N2 avian influenza outbreaks have caused great economic losses to the poultry industry in recent decades due to a decrease of egg production, high morbidity, and mortality. Due to different antigenic variants, Influenza virus has become problematical because it has the ability to cross the species barrier. As it is highly pathogenic so its diagnosis and vaccines are of high importance. Hemagglutination inhibition (HI) test is mostly used for subtyping and detection of antibody titer against the virus. Furthermore, its continuous mutations in the HA gene transforms AIV subtype H9N2 (a low pathogenic subtype) into high pathogenic virus subtypes like H5N2 and H7N7 that may have pandemic potential. Thus, it is necessary to identify various antigenic variants of Influenza virus, so it is direly needed to study the HA gene, its attachment to host receptors, the release of genetic material and pathogenicity. In the present study, virus samples from poultry were isolated. Both serological and molecular confirmation was done for 100 samples collected from the different area. They were properly labeled and prepared for the process of egg inoculation in embryonated eggs. The virus was grown in amnioallantoic membrane of embryonated eggs and harvested fluid is then proceeded for confirmatory testing. Hemagglutination and Hemagglutination inhibition testing was done. RNA was extracted by the kit method and cDNA was synthesized. Reverse transcriptase (RTPCR) was performed using specific primer sets and then the PCR product was run on agarose gel. The bands obtained were sent for sequencing.