Canine Circovirus in Foxes from Northern Italy: Where Did It All Begin?

Abstract

Canine circovirus (CanineCV) is a recently identified virus affecting both domestic and wild carnivores, including foxes, sometimes in presence of severe clinical signs. Its circulation in wild animals can thus represent a potential threat for endangered species conservation and an infection source for dogs. Nevertheless, no data were available on its circulation in the Alps region of Northern Italy. In the present study, samples collected from 186 foxes in the period 2009–2020 from Valle d’Aosta and Veneto regions were tested using a real-time PCR assay, demonstrating a viral circulation of approximatively 2–5%, depending on the considered regions. Two complete or almost complete genome sequences were obtained, highlighting that the detected strains were part of a so defined “fox only” clade, which suggests that, despite common contact opportunities, Alps foxes are not involved in frequent transmission events to domestic dogs. Such genetic isolation could be at least partially attributed to some sort of independent evolution occurred in the foxes, leading to species barrier. Additionally, CanineCV strains in foxes from Italy were unexpectedly related to those previously identified in foxes from the United Kingdom and Scandinavian area. Combining the history of fox distribution in Europe since the last glacial maximum (LGM) with the viral history allowed us to speculate a long-standing coexistence between European canine circovirus and this host, justifying the peculiar geographic distribution and evolutionary paths of the fox infecting clade.

The Oryx Antelope (Oryx gazella): An Unexpected Host for Porcine Circovirus-2 (PCV-2)

“…Similarly, another member of porcine circoviruses, Porcine circovirus 3, has been occasionally detected in ruminants, rodents, canines and insects [18]. Similar conclusions can be drawn for other circoviruses such as Beak and Feather Disease virus [20,21] or canine circovirus [22].…”

Detection and Genomic Characterization of Canine Circovirus in Iran

“…In our study, no wild carnivores i.e., foxes and wolves were sampled, thus preventing the evaluation of the epidemiological role of these animals in Iran. To date, circulation of CaCV in wild carnivores has been described only in European countries [ 12 , 13 , 14 , 16 ].…”

“…Subsequent studies in China [ 4 ], Thailand [ 5 ], Turkey [ 6 ], Italy [ 7 ], Germany [ 2 ], Brazil [ 8 ], Argentina [ 9 ], Vietnam [ 10 ] and Colombia [ 11 ] have revealed that CaCV is broadly circulating in domestic dog populations worldwide. Interestingly, CaCV and genetically related CVs have also been detected in other canids, including wolves and foxes [ 12 , 13 , 14 , 15 , 16 ]. Moreover, recent evidence shows the virus might have circulated in wild species for a long time before its first discovery in 2012 [ 16 ].…”

“…The ecology of CaCV in its animal hosts remains unexplored, and it is still unclear whether the virus can infect other animal hosts and what the modalities of transmission are between domestic and wild canids. Like other ssDNA viruses, CVs show a high genetic plasticity that might theoretically explain the ability of CaCV to cross the species barrier [ 13 ]. Although its pathogenic potential remains unclear, CaCV has been associated with respiratory and gastrointestinal disease and in some cases with systemic disease involving vasculitis [ 2 , 7 , 17 , 18 , 19 ].…”

Canine Circovirus Suppresses the Type I Interferon Response and Protein Expression but Promotes CPV-2 Replication

“…Subsequently, CanineCV was identified in Italy and was thought to be the causative agent of canine necrotizing vasculitis and lymph node granuloma, which can cause vomiting and hemorrhagic diarrhea in dogs [ 2 , 3 ]. To date, CanineCV has been reported in several countries, indicating that the virus has spread worldwide [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. The genome of CanineCV is approximately 2063–2064 nt in size and primarily contains three open reading frames (ORFs).…”