Time in the Laboratory, but Not Exposure to a Chytrid Fungus, Results in Rapid Change in Spring Peeper (Pseudacris crucifer) Skin Bacterial Communities

Interactions between pathogens and the symbiotic microbial communities that reside in hosts can impact disease processes. Symbiotic microbial communities can act to prevent pathogen infection in some instances, while in other instances, pathogens can disrupt these symbiotic communities. We sought to address these interactions between the fungal skin pathogen Batrachochytrium dendrobatidis (Bd) and the skin bacterial communities of adult Spring Peepers (Pseudacris crucifer). In the laboratory, frogs were exposed to Bd zoospores for a 12-hour period and then monitored for five days. Bacterial community composition on the skin was assessed upon initial collection, 24 hours post-exposure, and at the conclusion of the experiment using 16S rRNA gene amplicon sequencing. Little impact on the bacterial community was observed as a result of Bd exposure, suggesting that the timeline was either too short to observe the effects of Bd, or that the skin communities are resilient in the face of such short exposure periods. In contrast, laboratory housing was associated with changes in skin bacterial community composition, in terms of both relative abundances and bacterial taxa that were present. These findings suggest that even a short time away from their natural environment can have strong effects on the composition of amphibian skin communities and that Bd exposure may not always disrupt these skin communities.

Automated summary

The study found that exposure to Bd did not significantly impact the skin bacterial community. However, laboratory housing was associated with changes in skin bacterial community composition.