Identification of novel circovirus and anelloviruses from wolverines using a non-invasive faecal sampling approach

Viruses in the families Circoviridae and Anelloviridae have circular single-stranded DNA genomes and have been identified in various animal species. Some members of the Circoviridae family such as beak and feather disease and porcine circovirus have been found to cause disease in their host animals. Anelloviruses on the other hand have not been identified to cause disease in their hosts but are highly prevalent in mammalian species. Using a non-invasive sampling approach, we identified novel circovirus and anelloviruses from faecal samples of wolverines dwelling in Montana, USA. Wolverines are forest carnivores that feed on a wide variety of carrion and other prey species, and they occupy diverse habitats across northern Europe to North America. Little is known about viruses associated with wild wolverines. Our investigation of the faecal samples resulted in the identification of a novel circovirus from three out of four wolverine samples, two collected in 2018 and one in 2019. Comparison with other circoviruses shows it is most closely related to a porcine circovirus 3, sharing ~69% identity. Additionally, three anellovirus genomes were recovered from two wolverine faecal samples which share 68-–69% ORF1 nucleotide similarity with an anellovirus from another mustelid species, pine martens. Here we identify novel single-stranded DNA viruses associated with wolverine and open up new avenues for research.