Genetic Characterization of Fowl Adenovirus Strains Isolated from Poultry in China.

Fowl adenoviruses (FAdVs) infect chickens worldwide, resulting in global economic losses in the poultry industry. We examined the strains present in chickens in regions of China where infections are particularly prevalent. Fifteen FAdV strains were successfully isolated in the field. The L1 loop region of the hexon gene was sequenced to genetically identify the FAdV isolates. By comparing these sequences to adenovirus reference strain sequences using phylogenetics, 15 adenovirus strains were found to cluster into two distinct species. One cluster containing 12 strains belonged to the fowl adenoviruses C species and serotyped as FAdV-4. The other cluster containing three strains belonged to the fowl adenoviruses E species and serotyped as FAdV-10. To our knowledge, this is the first report of the existence of fowl adenoviruses E in China. Furthermore, at least two types of fowl adenovirus strains are predominant among poultry in China. Cumulatively, this study helps lays the groundwork for future research on the pathogenicity and potential treatment measures for FAdV infections in chickens.