Novel Parvovirus Related to Primate Bufaviruses in Dogs

Abstract

A novel protoparvovirus species, related genetically to human bufaviruses, was identified in dogs with respiratory signs. The canine bufavirus was distantly related to the well-known canine protoparvovirus, canine parvovirus type 2, sharing low amino acid identities in the nonstructural protein 1 (40.6%) and in the capsid protein 1 (33.4%). By screening collections of fecal, nasal, and oropharyngeal samples obtained from juvenile dogs (<1 year of age), canine bufavirus DNA appeared as a common component of canine virome. The virus was common in the stool samples of dogs with or without enteric disease and in the nasal and oropharyngeal swab samples of dogs with respiratory signs. However, the virus was not detected in nasal and oropharyngeal swab samples from animals without clinical signs.

Keywords: CIRD; bufavirus; dog; enteric infections; kennel cough; parvovirus; protoparvovirus; respiratory infections; viruses.

Figure 1

Genome organization of canine bufavirus. A) Positions of the conserved helicase Walker A (GxxxxGKS), Walker B (EE), and replication initiator motifs (HuHuu and YuxK) in NS1 and of the phospholipase A2 (PLA2) and glycine-rich region (G-rich) in VP1 and VP2. B) Putative splicing mechanism in the VP1 gene of canine bufavirus, human bufaviruses, and other protoparvoviruses. Two potential splice sites are a potential donor site (AG↓GT) at nt 1931 and an acceptor site (AG↓G) at nt 2115. The putative VP1 sequence starts with ATG at the end of ORF1 at nt 1906 upstream of the splice donor site at nt 1931. Gray shading indicates strictly and highly conserved bases. GenBank accession numbers are provided for reference sequences. NS, nonstructural; UTR, untranslated region; VP, viral capsid protein.

Figure 2

Capsid-based phylogenetic tree displaying the diversity of protoparvoviruses. The protoparvoviruses officially recognized by the International Committee on Taxonomy of Viruses are included, along with nonclassified (NC) protoparvoviruses. The tree was generated using the neighbor-joining method with the Jukes-Cantor algorithm of distance correction, with bootstrapping over 1,000 replicates. Box indicates canine bufavirus strains. GenBank accession numbers are provided for reference isolates; gray fox amdovirus (GenBank accession no. JN202450) is used as outgroup. Scale bar indicates nucleotide substitutions per site.