The evolution of a bat population with white-nose syndrome (WNS) reveals a shift from an epizootic to an enzootic phase

Abstract

BackgroundWhite-nose Syndrome (WNS) is a mycosis caused by a cutaneous infection with the fungus Pseudogymnoascus destructans (Pd). It produces hibernation mortality rates of 75–98% in 4 bats: Myotis lucifugus, M. septentrionalis, M. sodalis, and Perimyotis subflavus. These high mortality rates were observed during the first several years after the arrival of P. destructans at a hibernation site. Mortality is caused by a 60% decrease in torpor bout duration, which results in a premature depletion of depot fat prior to spring.ResultsLittle is known about the long-term effects of Pd on torpor and mortality, thus we conducted a 9-year study on M. lucifugus at 5 of the hibernation sites where Pd first appeared in North America during the winter of 2007–08. The M. lucifugus hibernating at one of these sites one year after the arrival of Pd (2008–09) had: a) a mean torpor bout duration of 7.6 d, b) no depot fat reserves by March, and c) an apparent over-winter mortality rate of 88%. The M. lucifugus hibernating at this same site 6–9 years after the arrival of Pd, in contrast, had: a) a mean torpor bout duration of 14.7 d, b) depot fat remaining in March, and c) an apparent mortality rate of 50%. The number of M. lucifugus hibernating at 2 of these sites has consistently increased since 2010 and is now more than 3.0-fold higher than the number remaining after the winter of 2008–09.ConclusionsThese findings indicate that this population of M. lucifugus has evolved mechanisms to hibernate well in the presence of Pd, thus reducing over-winter mortality.

Disease recovery in bats affected by white-nose syndrome

“…Despite these differences, recovery occurred on a similar time scale as for freeranging bats in the wild and, in our view, these results are useful for understanding the recovery process from WNS. WNS is usually considered a disease of hibernation but our study highlights that population viability will depend not just on energetics of hibernation (Frank et al, 2019), but also energy balance during healing. Although there are few examples of wildlife disease as a driver of seasonal carryover effects, carryover (Norris, 2005;O'Connor et al, 2014) is thought to play a role in the impacts of WNS (Davy et al, 2017).…”

Novel inactivation of the causative fungal pathogen of white-nose syndrome with methoxsalen plus ultraviolet A or B radiation

“…Pseudogymnoascus destructans, a fungal pathogen first recognized in Northern American bat caves in 2006, has caused a significant depletion of select bat populations [11]. Experimental treatments and vaccines are being studied to limit the spread and mortality of bats due to WNS, yet none have found widespread application [5].…”

“…White-nose syndrome, a recently identified disease caused by Pd , has devastated North American bat populations [ 9 – 11 ]. Pseudogymnoascus destructans is a psychrophilic filamentous fungus [ 12 – 14 ], with an optimal growth range of 12.5–15.8°C [ 15 ].…”

Genome-Wide Changes in Genetic Diversity in a Population of Myotis lucifugus Affected by White-Nose Syndrome

“…Models parameterized with long-term data on fungal loads, infection intensity and counts of M. lucifugus at hibernacula have suggested development of either tolerance or resistance in these persisting populations (Frick et al 2017). This is supported by reports of infected individuals not arousing from torpor as frequently as during the acute phase of the zoonosis (Lilley et al 2016;Frank et al 2019). Because WNS has resulted in massive population declines in some M. lucifugus, there is a possibility that selection could occur for alleles conferring resistance or tolerance within the standing genetic variation.…”