Characterization of reoviruses isolated from some broiler breeder flocks in Iran

Avian reoviruses (ARVs) are considered as an important cause of several diseases in poultry, particularlyarthritis and tenosynovitis. Tenosynovitis and arthritis, which are among the causes of chronic lameness inbreeder flocks, can result in reduced egg production and culling of breeder hens. In this study, the molecularcharacteristics of ARVs in some broiler breeder flocks were investigated in Iran. After RNA extraction of thefield samples, reverse transcription-polymerase chain reaction (RT-PCR) was performed to amplify two regionsof ARVs for S1 and S4 genes. The positive samples were further analyzed by five restriction enzymes inrestriction fragment length polymorphism (RFLP) for determining the strains. The phylogenetic analysis of S1and S4 genes from the isolates indicated divergence into five and four major lineages, respectively. Thesequence analysis of S1 and S4 genes of ARVs revealed that most of the positive samples were closely related totenosynovitis-inducing ARVs (with less than 2% nucleotide divergence). Also, these samples were mosthomologous to S1133 strain, with 99.90% nucleotide and amino acid affinity.