Integrated Use of Molecular Techniques to Detect and Genetically Characterise DNA Viruses in Italian Wolves (Canis lupus italicus)

Abstract

In this study, internal organs (tongue, intestine, and spleen) of 23 free-ranging Italian wolves (Canis lupus italicus) found dead between 2017 and 2019 were tested for Carnivore protoparvovirus 1, Canine adenovirus (CAdV), and Canine circovirus (CanineCV) using real-time PCR assays. Genetic characterisation of the identified viruses was carried out by amplification, sequencing, and analysis of the complete viral genome or informative viral genes. All the wolves tested positive for at least one of the DNA viruses screened, and 11/23 were coinfected. Carnivore protoparvoviruses were the most frequently detected viruses (21/23), followed by CanineCV (11/23) and CAdV (4/23). From the analysis of the partial VP2 gene of 13 carnivore protoparvoviruses, 12 were canine parvovirus type 2b, closely related to the strains detected in dogs and wild carnivores from Italy, and one was a feline panleukopenia-like virus. Of the four CAdV identified, two were CAdV-1 and two were CAdV-2. The complete genome of seven CanineCVs was sequenced and related to the CanineCV identified in dogs, wolves, and foxes worldwide. Close correlations emerged between the viruses identified in wolves and those circulating in domestic dogs. Further studies are needed to investigate if these pathogens may be potentially cross-transmitted between the two species.