New research demonstrated that Geomyces destructans, the fungus responsible for devastating declines of bat populations in eastern North America is most probably introduced by visitors from Europe. This fungus was found in European caves but affected bats do not develop WNS.
Published online before print April 9, 2012, doi: 10.1073/pnas.1200374109
PNAS May 1, 2012 vol. 109 no. 18 6999-7003
Lisa Warnecke, James M. Turner, Trent K. Bollinger, Jeffrey M. Lorch, Vikram Misra, Paul M. Cryan, Gudrun Wibbelt, David S. Blehert, and Craig K. R. Willis, From the Cover: Inoculation of bats with European Geomyces destructans supports the novel pathogen hypothesis for the origin of white-nose syndrome, PNAS 2012 109: 6999-7003.
White-nose syndrome (WNS) is an emerging disease of hibernating bats associated with cutaneous infection by the fungus Geomyces destructans (Gd), and responsible for devastating declines of bat populations in eastern North America. Affected bats appear emaciated and one hypothesis is that they spend too much time out of torpor during hibernation, depleting vital fat reserves required to survive the winter. The fungus has also been found at low levels on bats throughout Europe but without mass mortality. This finding suggests that Gd is either native to both continents but has been rendered more pathogenic in North America by mutation or environmental change, or that it recently arrived in North America as an invader from Europe. Thus, a causal link between Gd and mortality has not been established and the reason for its high pathogenicity in North America is unknown. Here we show that experimental inoculation with either North American or European isolates of Gd causes WNS and mortality in the North American bat, Myotis lucifugus. In contrast to control bats, individuals inoculated with either isolate of Gd developed cutaneous infections diagnostic of WNS, exhibited a progressive increase in the frequency of arousals from torpor during hibernation, and were emaciated after 3–4 mo. Our results demonstrate that altered torpor-arousal cycles underlie mortality from WNS and provide direct evidence that Gd is a novel pathogen to North America from Europe.