Detection of reoviruses in proventriculitis of broiler chickens in Isfahan province by RT-PCR method and pathological evaluation of related lesions

Proventriculitis is a disease characterized by enlargement of the proventriculus. Several factors including infectious and non-infectious agents play a role in its development. Reoviruses could be considered as a main causal agent of proventriculitis in chickens. Based on clinical evidence and reports of the prevalence of reovirus infection in poultry farms in Iran, the enlargement of proventriculus and proventriculitis may be related to the reovirus infections. In the present study, to detect reoviruses in the proventriculus samples, the S1 gene was amplified by RT-PCR (Reverse Transcription-Polymerase Chain Reaction). According to the findings, out of 75 proventriculus samples collected from 15 broiler farms with large proventriculus in Isfahan province, 46 samples (61.33% of the samples) and 10 farms (66.66% of the studied farms) were positive for reovirus based on the amplification of the 532 bp fragment related to the S1 gene. The collected proventriculi were all macroscopically larger than normal and had more thickness. The area connecting the proventriculus to the gizzard was loose and lacked sufficient consistency. In addition, the mucosal layer of the proventriculus was slimy and contained yellow secretions. In all the histopathological sections related to positive samples, necrosis along with inflammatory cells were visible in the superficial and deep glands of the proventriculus. In general, it seems that there is infection with reoviruses in broiler chickens of Isfahan province and this infection can play a role in causing the inflammation and enlargement of the proventriculus, therefore, necessary measures should be taken to control and prevent this infection in broiler chickens.