Naturally transmitted mouse viruses highlight the heterogeneity of virus transmission dynamics in the dirty mouse model

Increasing evidence supports microbial exposure as a critical factor in shaping responses to immune challenges such as infections and vaccinations. However, many experimental models introducing microbial exposure into laboratory animals have confounding factors that may impact phenotypes and are not well characterized. Here, we characterized the pet store reservoir virome diversity, prior infection history, and transmission kinetics. We found significant heterogeneity across these features of the pet store cohousing model. Moreover, we leveraged this model to investigate the tropism of two less characterized viruses-murine Kobuvirus and murine astrovirus 2-in a natural transmission setting. These findings highlight the importance of characterizing the virome of pet store reservoirs to better mimic microbial exposure in humans.