Pseudogymnoascus destructans: Causative Agent of White-Nose Syndrome in Bats Is Inhibited by Safe Volatile Organic Compounds.

Sally Padhi,Itamar Dias,Victoria Korn,Joan Bennett

doi:10.3390/jof4020048

Abstract

White-nose syndrome (WNS) is caused by Pseudogymnoascus destructans, a psychrophilic fungus that infects hibernating bats and has caused a serious decline in some species. Natural aroma compounds have been used to control growth of fungal food storage pathogens, so we hypothesized that a similar strategy could work for control of P. destructans. The effectiveness of exposure to low concentrations of the vapor phase of four of these compounds was tested on mycelial plugs and conidiospores at temperatures of 5, 10 and 15 °C. Here we report the efficacy of vapor phase mushroom alcohol (1-octen-3-ol) for inhibiting mycelial and conidiospore growth of P. destructans at 0.4 and 0.8 µmol/mL and demonstrate that the R enantiomer of this compound is more effective than the S enantiomer, supporting the finding that biological systems can be sensitive to stereochemistry. Further, we report that vapor phase leaf aldehyde (trans-2-hexenal), a common aroma compound associated with cut grass odors and also the major volatile compound in extra virgin olive oil, is more effective than mushroom alcohol. At 0.05 µmol/mL, trans-2-hexenal is fungicidal to both conidiospores and mycelia of P. destructans.

Highlights

White-nose syndrome (WNS), a fungal disease of hibernating bats, has decimated bat populations in North America [1,2] and threatens the extinction of several bat species [3]
WNS is caused by Pseudogymnoascus destructans, a cold-loving fungus with growth restricted to temperatures of approximately 3–15 ◦ C and >90%
In order to determine if exposure to lower concentrations of trans-2-hexenal were inhibitory to the germination of P. destructans conidiospores, a new exposure system was designed that would allow the testing of lower concentrations of this compound. trans-2-hexenal is not water soluble and we have found that non-polar solvents that can be used to dissolve it have independent effects on the growth of P. destructans

Summary

Introduction

White-nose syndrome (WNS), a fungal disease of hibernating bats, has decimated bat populations in North America [1,2] and threatens the extinction of several bat species [3]. WNS probably was introduced to North America from Europe where the disease is endemic but where bats appear to be resistant [4]. The steep declines in North American bat populations make WNS perhaps the most devastating mammalian wildlife disease in recent history [5]. Population sizes have declined 99% in WNS-infected hibernacula [3,6,7]. The disease infects the cutaneous tissues of bats, producing a white-colored fungal growth on the muzzle and wings [11]. WNS pathology includes changes in electrolyte balance and hydration [11,16], chronic respiratory acidosis [17], immune response [18] and oxidative stress [19]

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Conclusion