Virome of canine lymph nodes: identification of viruses with zoonotic potential

Zoonotic infectious diseases have significantly impacted global public health, as exemplified by the COVID-19 pandemic that triggered an unprecedented worldwide crisis with millions of infections. Among animals closely associated with humans, canines occupy a prominent position due to their extensive integration into human daily life. Consequently, investigating the virome of canines in close contact with humans holds significant scientific and public health implications.

This study selected lymph node tissues from 24 dogs in close contact with humans from Shanghai and Henan, specifically collecting submandibular lymph nodes and carefully removing surrounding fat and connective tissues. Through comprehensive metagenomic analysis, we assembled 17 complete viral genomes spanning 6 viral families, including Adenoviridae (n = 1), Paramyxoviridae (n = 1), Polyomaviridae (n = 1), Parvoviridae (n = 7), Circoviridae (n = 6), and Genomoviridae (n = 1). Phylogenetic analysis of these dominant viruses elucidated the evolutionary relationships between the assembled viral sequences in this study and known reference viruses. Notably, we discovered a novel virus belonging to the Genomoviridae family.

This research not only elucidates the remarkable diversity of the virome within canine lymph node tissues but also employs phylogenetic analysis to delineate the evolutionary relationships between these viruses and previously documented strains. Notably, this study represents the first identification of parvoviruses and circoviruses in canine lymph nodes that exhibit high sequence homology with human viral strains, suggesting that these canine-derived and human-associated viruses may have diverged from a common ancestor.