Genomic characterization of a broiler reovirus field strain detected in Pennsylvania

Avian reovirus (ARV) infections have been increasingly diagnosed in Pennsylvania (PA) from 2011 to the present time. A field ARV strain (Reo/PA/Broiler/05682/12) isolated from sick broilers suffered from severe arthritis/tenosynovitis of a PA broiler flock was conducted full genome sequence studies using RT-PCR and RACE techniques. The complete genome of the PA broiler ARV field strain was 23,494. bp in length with an approximately 50% G+C content and 10 dsRNA segments encoding 12 viral proteins. The 10 genomic segments were ranged from 1192. bp (S4) to 3958. bp (L1) in length, which were almost identical to those of published reference strains. The amino acid (aa) alignments of the putative proteins encoded by the ORF in each segment revealed a high similarity to the counterpart proteins encoded by other avian orthoreoviruses in the Orthoreovirus genus, particularly with the reference strain AVS-B (89.4-98.9%). The phylogenetic analysis of the nucleotide sequences of all 10 genome segments of the PA broiler ARV revealed that a moderate to significant nucleotide sequence divergence from sequences of cognate genome segments of reference ARV S1133 and 138 strains. These genomic data demonstrate that this PA broiler ARV field strain is a unique tenosynovitis ARV and is different from the traditional ARV vaccine strains.