Molecular identification of aviadenoviruses in broiler chickens suspected to inclusion body hepatitis in Golestan province, Iran

Background: Fowl adenoviruses (FAdVs) are distributed widely throughout the world, and domestic avian species of all ages are susceptible. Fowl aviadenoviruses (FAdVs) can be separated into 5 different species (A-E) with various genotypes and 12 serotypes. Some geno- or serotypes induce hepatitis-hydropericardium syndrome (HPS), inclusion body hepatitis (IBH), and adenoviral gizzard erosion (AGE). Aims: Detect FAdVs serologically and molecularly and sequencing of FAdVs in broiler flocks in Golestan province. Methods: From December 2017 to June 2018 liver tissues and blood samples were collected from 31 broiler flocks suspected of IBH. Polymerase chain reaction (PCR) was applied on liver samples and the positive samples were sequenced and antibody against FAdVs was measured by enzyme-linked immunosorbent assay (ELISA). Results: Out of 31 flocks, the titers of 29 flocks (93.5%) were high in ELISA test for FAdVs and 22 flocks (70.96%) were positive in PCR test. Sequence analysis indicated the isolates belonged to D and E genotype of adenovirus. Conclusion: Inclusion body hepatitis caused by FAdVs, are spreading increasingly in broiler flocks of Golestan province and more attention and surveillance programs of breeder and broiler farms are needed to develop preventive measures. Moreover, vaccination of poultry farms in Iran should be considered by more complement studies.