Detection and Molecular Identification of Reovirus in Broiler breeder Flocks

Avian Reovirus (ARVs) has a global distribution in nature and most clinical signs are found in the broiler type chicken. Objective: The study was conducted to detect and identify reovirus infection from vaccinated breeder chickens and their progenies.Materials & Methods: A total ۲۰ tissue and blood samples from vaccinated broiler breeders and their progenies with gastrointestinal or performance problems during peak production, were collected. Antibodies titer was measured by indirect ELISA test. The RNA extraction from samples was performed and cDNA prepared and directly used in the PCR reaction. Determination of nucleotide sequences using internal primers was bilaterally conducted. The analysis of thenucleotide sequences and their related amino acids was performed by the specialized software of Molecular Evolutionary Genetics Analysis, ۶th version.Result:The virus variant was detected in two vaccinated broiler breeders and five broiler flocks. The vaccine strains in breeder flocks include S۱۱۳۳, SS۴۱۲, ۱۷۳۳, ۲۴۰۸ belong to genotype ۱ reovirus phylogenetic tree. Sequenced ۷ isolated reovirus based on the σC revealed that they different from the reovirus vaccine and ۶ isolates belong to genotype ۱ of the phylogenetic tree while ۱ isolate also belongs to branch ۴ of phylogenetic tree. The study showed new reovirus strain isolated from vaccinated birds was differs from common strains used in the vaccines and it is essential to prevent the effects of the field reovirus on the performance of industrial poultry, by updating and made new commercial vaccines, live and killed, against reovirus.