Serological and Molecular detection of highly pathogenic avian influenza of Layan Hens circulating in Diyala Governorate

This study was conducted at the College of Veterinary Medicine, University of Diyala, to evaluate the seroprevalence and molecular detection of avian influenza virus (AIV) H۵N۸ in layer chickens. Samples were collected from eight commercial flocks displaying severe respiratory symptoms, facial edema, followed by cyanosis in all parts of unfeathered skin predominantly the wattles comb. Serological analysis was performed using ELISA on ۳۶۴ serum samples to detect IgG antibodies specific to AIV H۵N۸. The results showed a significant increase of IgG antibodies in such serum samples at days ۷۰ and ۲۰۰ of age. Additionally, ۴۸ postmortem tissue samples from trachea, lung, and liver were collected from birds at ۲۰۰ days of age for RT-PCR analysis by using specific primers for H۵N۸ strain. Results indicated that ۳۲ out of ۴۸ samples (۶۶.۶%) were positive for H۵N۸, confirmed by sequencing of the ۳۲۰ bp amplicon. The local H۵N۸ strain exhibited ۹۹% sequence identity with reference sequences and was registered in GenBank under accession number (ON۲۴۷۹۲۹.۱). Phylogenetic analysis showed that the local sample (ON۲۴۷۹۲۹.۱) was closely related to reference isolates from the NCBI, including MW۹۶۱۴۲۸.۱, MW۹۶۱۴۴۴.۱, MW۹۶۱۴۷۶.۱, MW۹۶۱۴۳۶.۱, and MW۹۶۱۴۸۴.۱, which were deposited from Nigeria.

کلیدواژه ها:

avian influenza virus (AIV) ، layer chickens ، ELISA ، RT-PCR ، GenBank