Emerging of a novel natural recombinant fowl adenovirus in China.

Outbreaks of hydropericardium syndrome and inclusion body hepatitis caused by fowl adenovirus (FAdV) have occurred in China since June 2015, resulting in significant economic loss to poultry industry. In this study, a novel FAdV, designated as AH720, with recombination among serotype FAdV-8a and FAdV-8b was isolated and characterized in China. Full genome analysis revealed that the AH720 has the genome backbone from FAdV-8b and the fibre gene from FAdV-8a. In an infection study, although AH720 was not lethal to chickens, AH720 did cause characteristic lesions of inclusion body hepatitis in the infected chickens. All these data not only provide strong evidences for the recombination among different serotype FAdVs, but also highlight the necessary for monitoring the molecular epidemiology of such recombinant FAdV to develop efficient strategies against FAdV.