Molecular Detection of Avian Metapneumovirus in Semnan BroilerFarms

  BACKGROUND: Avian Metapneumovirus (AMPV) causes mild to acute contagious infection of the upper respiratory tract in turkey and chicken with different mortality rate. OBJECTIVES: This study was aimed to molecular detection and subtyping of AMPV infection in broiler flocks using RT-PCR method in Semnan province on samples from ۲۰۱۶ to۲۰۲۰. METHODS: Sampling was carried out from the upper part of the trachea, choana, and sinuses of broiler chickens from the ۸۵ broiler flocks. All flocks were more than ۳ weeks of age. In total ۱۰ swabs were taken from each flock, while each ۵ were pooled as one sample (total two samples per flock). The samples were transferred to the laboratory for RNA extraction and RT-PCR amplification. RESULTS: Out of ۸۵ tested broiler flocks, ۳۰ (۳۵.۳%) were positive for AMPV using the Nd/Nx primer set. In addition, ۲۸ positive samples were found to be of subtype B using the Ga/G۱۲ primer set and ۲ remaining positive samples were non-subtype B, probably A, C or D subtypes. CONCLUSIONS: Since AMPV vaccination was not performed in Semnan province, it can be concluded that some cases were infected with the natural viruses. Therefore, vaccination could be effective in controlling AMPV-induced respiratory distress.

Keywords:

Avian Metapneumovirus , Broiler flocks , Nd/Nx primer , RT-PCR , Subtype B