Detection and identification of avian adenovirus in broiler chickens suspected of inclusion body hepatitis in Khuzestan, Iran during 2015-2016

Avian adenoviruses (AAV) are known as a very diverse group of pathogens causing a variety of clinical symptoms or being totally asymptomatic in poultry flocks. The aim of this study was the molecular detection of avian adenoviruses in broiler flocks suspected of the IBH and respiratory syndrome in the southwest of Iran. For this intent, the liver and lung samples with macroscopic lesions were collected from 30 different poultry flocks (poultry of slaughterhouse and flock mortalities). Subsequently, DNA was extracted from samples and examined using PCR. The L1 (Loop1) region of the hexon gene was amplified. PCR products were sequenced to reveal the identity of the avian adenoviruses. The data resulted from the nucleo tide sequencing were analyzed using programs and services provided by National Center for Biotechnology Information (NCBI). The results showed that the pools of liver samples from a 25 days old flock were positive in the PCR test. Based on the sequence data, adenoviruses belonged to the D genotype of avian adenoviruses. In phylogenetic analysis, FADV isolates were closely related to the FADV-11 isolates of Iran, China, Canada and Australia with nucleotide homology up to 99%. This is the first study on molecular detection and analyzing the nucleotide sequence of hexon gene fragment of FADV in broiler farms in Southwest Iran.