Data from: Temperature dependent effects of cutaneous bacteria on a frog's tolerance of fungal infection

Defense against pathogens is one of many benefits that bacteria provide to
animal hosts. A clearer understanding of how changes in the environment
affect the interactions between animals and their microbial benefactors is
needed in order to predict the impact and dynamics of emerging animal
diseases. Due to its dramatic effects on the physiology of animals and
their pathogens, temperature may be a key variable modulating the level of
protection that beneficial bacteria provide to their animal hosts. Here we
investigate how temperature and the makeup of the skin microbial community
impact the susceptibility of amphibian hosts to infection by
Batrachochytrium dendrobatidis, one of two fungal pathogens known to cause
the disease chytridiomycosis. To do this, we manipulated the skin
bacterial communities of susceptible hosts, northern cricket frogs (Acris
crepitans), prior to exposing these animals to Batrachochytrium
dendrobatidis under two different ecologically relevant temperatures. Our
manipulations included one treatment where antibiotics were used to reduce
the skin bacterial community, one where the bacterial community was
augmented with the antifungal bacterium, Stenotrophomonas maltophilia, and
one in which the frog's skin bacterial community was left intact. We
predicted that frogs with reduced skin bacterial communities would be more
susceptible (i.e., less resistant to and/or tolerant of Bd infection), and
frogs with skin bacterial communities augmented with the known antifungal
bacterium would be less susceptible to Bd infection and chytridiomycosis.
However, we also predicted that this interaction would be
temperature-dependent. We found a strong effect of temperature but not of
skin microbial treatment on the probability and intensity of infection
in Bd-exposed frogs. Whether temperature impacted survival,
however, differed among our skin microbial treatment groups, with animals
having more S. maltophilia on their skin surviving longer at 14 but not at
26 °C. Our results suggest that temperature was the predominant factor
influencing Bd's ability to colonize the host (i.e., resistance) but
that the composition of the cutaneous bacterial community was important in
modulating the host's ability to survive (i.e., tolerate) a heavy Bd
infection.