Four lineages of adenoviruses identified in raptors sampled in Spain

Adenoviruses infect a wide range of vertebrate species from fish to humans, including an especially large number of avian species. This study utilized viral metagenomic workflow coupled with targeted PCR to identify and characterize adenoviruses from cloacal swabs collected from 50 black kites (Milvus migrans), 11 ospreys (Pandion haliaetus), and 35 common kestrels (Falco tinnunculus) sampled in Spain. A total of eleven adenoviral genomes were determined from black kites (n = 8) and common kestrels (n = 3). Amino acid pairwise comparison of the DNA polymerase protein coupled with phylogenetic analysis shows that these viruses fall into four adenovirus lineages: two in the genus Aviadenovirus (raptor adenovirus 2 and 3) and two in the genus Siadenovirus (raptor adenovirus 1 and 4). The genomes of raptor adenovirus 1 and raptor adenovirus 2 belong to the classified species Siadenovirus raptoris and Aviadenovirus falconis, respectively, whereas raptor adenovirus 3 and 4 represent putative new species. This study expands the known host range of raptor-infecting viruses in the species Siadenovirus raptoris and Aviadenovirus falconis to include black kites and common kestrels, respectively. We also expand on the diversity knowledge of adenoviruses in black kites.