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 S۱ and S۴ genes. The positive samples were further analyzed by five restriction enzymes inrestriction fragment length polymorphism (RFLP) for determining the strains. The phylogenetic analysis of S۱and S۴ genes from the isolates indicated divergence into five and four major lineages, respectively. Thesequence analysis of S۱ and S۴ genes of ARVs revealed that most of the positive samples were closely related totenosynovitis-inducing ARVs (with less than ۲% nucleotide divergence). Also, these samples were mosthomologous to S۱۱۳۳ strain, with ۹۹.۹۰% nucleotide and amino acid affinity.

Keywords:

Molecular characteristics , Avian reoviruses , Tenosynovitis , Breeder flocks , Iran