The cutaneous microbiota of bats has in vitro antifungal activity against the white nose pathogen

Since its introduction into the USA, Pseudogymnoascus destructans (Pd), the fungal pathogen of white-nose syndrome, has spread killing millions of bats. Our objectives were to determine if resident bat skin bacteria have antifungal activity against Pd, as well as correlate differences in the bat cutaneous microbiota with the presence/absence of Pd. We hypothesized that the cutaneous microbiota of bats has the potential to function as an innate immune response to fungal pathogenicity through enrichment with bacteria possessing anti-Pd activity. To test this, we sampled the microbiota of tri-colored bats, adjacent roost surface, and soil from Pd positive caves to infer possible source-sink dynamics of antifungal taxa, we tested these bacteria for bioactivity in vitro, and lastly compared bacterial assemblages using both amplicon and shotgun high-throughput DNA sequencing. Results suggest that the presence of Pd has an inconsistent influence on the bat cutaneous microbial assemblage across sites. Operational taxonomic units (OTUs) that corresponded with cultured antifungal bacteria were present within all sample types but were significantly more abundant on bat skin when compared to the cave environment. These OTUs were not found more frequently or abundantly on Pd positive relative to negative bats suggesting that these members may play an important role within the host cutaneous microbial community.