Meeting Abstract
White-nose Syndrome (WNS) causes severe over-winter mortality for little brown bats (Myotis lucifugus). It is due to cutaneous infection with the fungus Pseudogymnoascus destructans (Pd) during hibernation. Big brown bats (Eptesicus fuscus) are resistant to infection with Pd. Hibernating M. lucifugus normally maintain a skin temperature (Tskin) of 5-7°C during torpor, whereas the Tskin of torpid E. fuscus is usually 12-13°C. We conducted analyses of wing epidermis from hibernating E. fuscus and M. lucifugus to determine their fatty acid compositions, and laboratory Pd culture experiments at 4.0 – 13.4°C to determine the effects of these fatty acids on the growth of this fungus. Our analyses revealed that the epidermis of both species contains the same 7 fatty acid types (14:0, 15:0, 16:0. 16:1, 18:0, 18:1, & 18:2), but the epidermis of M. lucifugus contains: a) more stearic (18:0) acid, b) less myristic (14:0) acid, c) less palmitoleic (16:1) acid, and, d) less oleic (18:1) acid, than that of E. fuscus. The growth of Pd was inhibited by: a) myristic and stearic acids at 10.5-13.4°C, only, b) oleic acid at 5.0 – 10.6°C, c) palmitoleic (16:1) acid, and, d) linoleic (18:2) acid at 5.0 – 10.6°C. One set of factors that enables E. fuscus to resist Pd infections (and thus WNS) is therefore the relatively higher myristic, palmitoleic, and oleic acid contents of the epidermis.
