Supporting Information from Temperature shifts associated with bat arousals during hibernation inhibit the growth of <i>Pseudogymnoascus destructans</i>

Temperature is a critically important factor in many infectious disease systems because it can regulate responses in both the host and the pathogen. White-nose syndrome (WNS) in bats is a severe infectious disease caused by the temperature-sensitive fungus, <i>Pseudogymnoascus destructans</i> (<i>Pd</i>). One feature of WNS is an increase in the frequency of arousal bouts (i.e. when bat body temperatures are elevated) in <i>Pd</i>-infected bats during hibernation. While several studies have proposed that increased frequency of arousals may play a role in the pathophysiology of WNS, it is unknown if the temperature fluctuations might mediate <i>Pd</i> growth. We hypothesized that exposure to a high frequency of elevated temperatures would reduce <i>Pd</i> growth due to thermal constraints on the pathogen. We simulated the thermal conditions for arousal bouts of uninfected and infected bats during hibernation (fluctuating from 8 to 25°C at two different rates) and quantified <i>Pd</i> growth <i>in vitro</i>. We found that increased exposure to high temperatures significantly reduced <i>Pd</i> growth. Because temperature is one of the most critical abiotic factors mediating host–pathogen interactions, resolving how <i>Pd</i> responds to fluctuating temperatures will provide insights for understanding WNS in bats and other fungal diseases.