IN SITU HYBRIDIZATION AND VIRUS CHARACTERIZATION OF SKUNK ADENOVIRUS IN NORTH AMERICAN WILDLIFE REVEALS MULTISYSTEMIC INFECTIONS IN A BROAD RANGE OF HOSTS.

Skunk adenovirus-1 (SkAdV-1) has been reported infecting several North American wildlife species; however, lesions associated with disease have not yet been completely characterized, particularly in porcupines. We describe and characterize the tissue distribution and lesions associated with SkAdV-1 infection in 24 wildlife diagnostic cases submitted between 2015 and 2020, including 16 North American porcupines (Erethizon dorsatum), three striped skunks (Mephitis mephitis), and five raccoons (Procyon lotor), which constitute a new host species. The most common lesion in all species was severe necrotizing bronchopneumonia with (n=12) or without (n=10) interstitial involvement. Intranuclear inclusion bodies were common in respiratory epithelium (n=21) and less often in renal tubular (n=6) and biliary epithelium (n=1). Several cases (n=4) had secondary bacterial infections, including Bordetella bronchiseptica, Pasteurella multocida, and Streptococcus zooepidemicus. In situ hybridization in porcupine (n=6), raccoon (n=1), and skunk (n=1) revealed SkAdV-1 DNA in multiple tissue types, including lung, trachea, turbinates, liver, kidney, lymph node, and brain, and multiple cell types including epithelial, endothelial, and mesothelial cells. These findings were consistent across species. Comparison of viral genomes from a porcupine and a raccoon with that originally isolated from a skunk demonstrated DNA point mutations affecting several viral genes, including the fiber protein gene. Our findings show the spectrum of disease associated with SkAdV-1 infection in a broad host range of wildlife species.