The presence of a fungal pathogen correlates with changes in microbial metacommunity structure

Metacommunity theory provides a framework for how community patterns arise from processes across scales, which is relevant for understanding patterns in host-associated microbial assemblages. Microbial metacommunities may have important roles in host health through interactions with pathogens; however, it is unclear how pathogens affect host microbial metacommunities. Here, we studied relationships between a fungal pathogen and a host-associated microbial metacommunity. We hypothesized that a fungal pathogen of bats, Pseudogymnoascus destructans, correlates with a shift in metacommunity structure and changes in relationships between community structure and factors structuring these assemblages. We sampled bat cutaneous microbial assemblages in the presence/absence of P. destructans during hibernation and analyzed microbial metacommunity structure and relationships with spatial and environmental variables. Absence of P. destructans correlated with a metacommunity characterized by a common core microbial group that was lacking in disease positive bats. Additionally, P. destructans presence correlated with a change in the relationship between community structure and an environmental structuring variable. Our results suggest that the fungal pathogen intensifies local processes (e.g. species sorting, antagonistic interactions) influencing a microbial metacommunity and highlights the importance of cutaneous microbial assemblages in host-pathogen interactions.