White-nose syndrome is associated with increased replication of a naturally persisting coronaviruses in bats

Area of Science:

• Veterinary Virology
• Wildlife Disease Ecology
• Mycology

Background:

• Bats host numerous viruses with zoonotic potential.
• White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans (Pd), severely impacts bat populations.
• The interplay between viral and fungal infections in bats is not well understood.

Purpose of the Study:

• To investigate the impact of co-infection with Myotis lucifugus coronavirus (Myl-CoV) and P. destructans (Pd) on disease severity, viral shedding, and molecular responses in little brown bats.
• To determine if WNS affects the shedding and immune response to persistent coronavirus infections.

Main Methods:

• Utilized bats naturally persistently infected with Myl-CoV from a previous P. destructans experimental inoculation study.
• Quantified viral RNA levels in bat intestines using molecular assays.
• Assessed fungal pathology and measured gene expression related to immune pathways (MAPK, cytokines).
• Measured coronavirus antibody levels.

Main Results:

• Bats co-infected with Myl-CoV and P. destructans showed a 60-fold increase in intestinal viral RNA compared to virus-only infected bats.
• Increased viral RNA correlated with the severity of fungal pathology.
• Fungal infection altered gene expression in the MAPK pathway and cytokine transcripts, regardless of viral presence.
• Coronavirus antibody levels were higher in bats infected with the fungus.

Conclusions:

• Systemic effects of WNS may suppress anti-viral responses in bats persistently infected with Myl-CoV.
• Co-infection with P. destructans can increase the shedding potential of M. lucifugus coronavirus.
• This highlights the complex interactions between fungal and viral pathogens in wildlife and potential implications for spillover events.