Search

Emerging infectious diseases are a severe conservation threat for a variety of plants and animals. In North America, several bat species are threatened by white-nose disease, which has caused an unprecedented mass mortality of > 6 million bats since 2006. The fungus Pseudogymnoascus (Geomyces) destructans is the causative agent of the disease. Though asexual reproduction is the norm, sexual reproduction is possible as two mating types exist. Sexual reproduction has been implicated in the emergence of virulent strains of fungi but to date no rapid means of mating type characterisation was available for P. destructans. In this study, three mating type-specific primer sets were designed and tested on 80 isolates. The primers were multiplexed with microsatellite loci allowing for rapid and concurrent genotyping and mating type assignment. These markers will have great utility in better understanding and predicting the population dynamics and evolutionary potential of this fungus, including the emergence of virulent strains.

Hibernating bats have undergone severe recent declines across the eastern United States, but the cause of these regional-scale declines has not been systematically evaluated. We assessed the influence of white-nose syndrome (an emerging bat disease caused by the fungus Pseudogymnoascus destructans, formerly Geomyces destructans) on large-scale, long-term population patterns in the little brown myotis (Myotis lucifugus), the northern myotis (Myotis septentrionalis), and the tricolored bat (Perimyotis subflavus). We modeled population trajectories for each species on the basis of an extensive data set of winter hibernacula counts of more than 1 million individual bats from a 4-state region over 13 years and with data on locations of hibernacula and first detections of white-nose syndrome at each hibernaculum. We used generalized additive mixed models to determine population change relative to expectations, that is, how population trajectories differed with a colony's infection status, how trajectories differed with distance from the point of introduction of white-nose syndrome, and whether declines were concordant with first local observation of the disease. Population trajectories in all species met at least one of the 3 expectations, but none met all 3. Our results suggest, therefore, that white-nose syndrome has affected regional populations differently than was previously understood and has not been the sole cause of declines. Specifically, our results suggest that in some areas and species, threats other than white-nose syndrome are also contributing to population declines, declines linked to white-nose syndrome have spread across large geographic areas with unexpected speed, and the disease or other threats led to declines in bat populations for years prior to disease detection. Effective conservation will require further research to mitigate impacts of white-nose syndrome, renewed attention to other threats to bats, and improved surveillance efforts to ensure early detection of white-nose syndrome.

White-nose syndrome is an often lethal fungal infection of bats that is caused by the fungus Pseudogymnoascus destructans, formerly Geomyces destructans. The fungal spores can persist for extended periods of time in the soil and on surfaces in caves where it might be found even after the bats depart. In 2010, a single bat, Myotis velifer, from a western Oklahoma gypsum cave, was initially diagnosed by the U.S. Geological Survey National Wildlife Health Center, as “suspect white-nose syndrome.” Based on this, we decided to examine soil samples from various bat caves across Oklahoma for the presence of P. destructans. We used Real-time Polymerase Chain Reaction to analyze 83 soil samples from 17 caves in Oklahoma. None of the soil samples were found to contain genetic material from P. destructans. We postulate that P. destructans has not yet reached Oklahoma because of the negative Real-time Polymerase Chain Reaction results, because a National Wildlife Health Center reexamination of the original b...

White-nose syndrome (WNS) is a fungal disease caused by Pseudogymnoascus destructans (Pd) that affects bats during hibernation. Although millions of bats have died from WNS in North America, mass mortality has not been observed among European bats infected by the fungus, leading to the suggestion that bats in Europe are immune. We tested the hypothesis that an antibody-mediated immune response can provide protection against WNS by quantifying antibodies reactive to Pd in blood samples from seven species of free-ranging bats in North America and two free-ranging species in Europe. We also quantified antibodies in blood samples from little brown myotis (Myotis lucifugus) that were part of a captive colony that we injected with live Pd spores mixed with adjuvant, as well as individuals surviving a captive Pd infection trial. Seroprevalence of antibodies against Pd, as well as antibody titers, was greater among little brown myotis than among four other species of cave-hibernating bats in North America, including species with markedly lower WNS mortality rates. Among little brown myotis, the greatest titers occurred in populations occupying regions with longer histories of WNS, where bats lacked secondary symptoms of WNS. We detected antibodies cross-reactive with Pd among little brown myotis naïve to the fungus. We observed high titers among captive little brown myotis injected with Pd. We did not detect antibodies against Pd in Pd-infected European bats during winter, and titers during the active season were lower than among little brown myotis. These results show that antibody-mediated immunity cannot explain survival of European bats infected with Pd and that little brown myotis respond differently to Pd than species with higher WNS survival rates. Although it appears that some species of bats in North America may be developing resistance to WNS, an antibody-mediated immune response does not provide an explanation for these remnant populations.

White-nose syndrome (WNS) of bats has devastated bat populations in eastern North America since its discovery in 2006. WNS, caused by the fungus Pseudogymnoascus destructans, has spread quickly in North America and has become one of the most severe wildlife epidemics of our time. While P. destructans is spreading rapidly in North America, nothing is known about the sexual capacity of this fungus. To gain insight into the genes involved in sexual reproduction, we characterized the mating-type locus (MAT) of two Pseudogymnoascus spp. that are closely related to P. destructans and homothallic (self-fertile). As with other homothallic Ascomycota, the MAT locus of these two species encodes a conserved α-box protein (MAT1-1-1) as well as two high-mobility group (HMG) box proteins (MAT1-1-3 and MAT1-2-1). Comparisons with the MAT locus of the North American isolate of P. destructans (the ex-type isolate) revealed that this isolate of P. destructans was missing a clear homolog of the conserved HMG box protein (MAT1-2-1). These data prompted the discovery and molecular characterization of a heterothallic mating system in isolates of P. destructans from the Czech Republic. Both mating types of P. destructans were found to coexist within hibernacula, suggesting the presence of mating populations in Europe. Although populations of P. destructans in North America are thought to be clonal and of one mating type, the potential for sexual recombination indicates that continued vigilance is needed regarding introductions of additional isolates of this pathogen.

Definitive diagnosis of the bat disease white-nose syndrome (WNS) requires histologic analysis to identify the cutaneous erosions caused by the fungal pathogen Pseudogymnoascus [formerly Geomyces] destructans (Pd). Gross visual inspection does not distinguish bats with or without WNS, and no nonlethal, on-site, preliminary screening methods are available for WNS in bats. We demonstrate that long-wave ultraviolet (UV) light (wavelength 366-385 nm) elicits a distinct orange-yellow fluorescence in bat-wing membranes (skin) that corresponds directly with the fungal cupping erosions in histologic sections of skin that are the current gold standard for diagnosis of WNS. Between March 2009 and April 2012, wing membranes from 168 North American bat carcasses submitted to the US Geological Survey National Wildlife Health Center were examined with the use of both UV light and histology. Comparison of these techniques showed that 98.8% of the bats with foci of orange-yellow wing fluorescence (n=80) were WNS-positive based on histologic diagnosis; bat wings that did not fluoresce under UV light (n=88) were all histologically negative for WNS lesions. Punch biopsy samples as small as 3 mm taken from areas of wing with UV fluorescence were effective for identifying lesions diagnostic for WNS by histopathology. In a nonlethal biopsy-based study of 62 bats sampled (4-mm diameter) in hibernacula of the Czech Republic during 2012, 95.5% of fluorescent (n=22) and 100% of nonfluorescent (n=40) wing samples were confirmed by histopathology to be WNS positive and negative, respectively. This evidence supports use of long-wave UV light as a nonlethal and field-applicable method to screen bats for lesions indicative of WNS. Further, UV fluorescence can be used to guide targeted, nonlethal biopsy sampling for follow-up molecular testing, fungal culture analysis, and histologic confirmation of WNS.

White-nose syndrome is a fungal disease that has decimated bat populations across eastern North America. Identification of the etiologic agent, Pseudogymnoascus destructans (formerly Geomyces destructans ), in environmental samples is essential to proposed management plans. A major challenge is the presence of closely related species, which are ubiquitous in many soils and cave sediments and often present in high abundance. We present a dual-probe real-time quantitative PCR assay capable of detecting and differentiating P. destructans from closely related fungi in environmental samples from North America. The assay, based on a single nucleotide polymorphism (SNP) specific to P. destructans , is capable of rapid low-level detection from various sampling media, including sediment, fecal samples, wing biopsy specimens, and skin swabs. This method is a highly sensitive, high-throughput method for identifying P. destructans , other Pseudogymnoascus spp., and Geomyces spp. in the environment, providing a fundamental component of research and risk assessment for addressing this disease, as well as other ecological and mycological work on related fungi.

White-nose syndrome (WNS) of bats, caused by the fungus previously known as Geomyces destructans, has decimated populations of insectivorous bats in eastern North America. Recent work on fungi associated with bat hibernacula uncovered a large number of species of Geomyces and allies, far exceeding the number of described species. Communication about these species has been hindered by the lack of a modern taxonomic evaluation, and a phylogenetic framework of the group is needed to understand the origin of G. destructans and to target closely related species and their genomes for the purposes of understanding mechanisms of pathogenicity. We addressed these issues by generating DNA sequence data for the internal transcribed spacer (ITS) region, nuclear large subunit (LSU) rDNA, MCM7, RPB2, and TEF1 from a diverse array of Geomyces and allies that included isolates recovered from bat hibernacula as well as those that represent important type species. Phylogenetic analyses indicate Geomyces and allies should be classified in the family Pseudeurotiaceae, and the genera Geomyces, Gymnostellatospora, and Pseudogymnoascus should be recognized as distinct. True Geomyces are restricted to a basal lineage based on phylogenetic placement of the type species, Geomyces auratus. Thus, G. destructans is placed in genus Pseudogymnoascus. The closest relatives of Pseudogymnoascus destructans are members of the Pseudogymnoascus roseus species complex, however, the isolated and long branch of P. destructans indicates that none of the species included in this study are closely related, thus providing further support to the hypothesis that this pathogen is non-native and invasive in eastern North America. Several conidia-producing isolates from bat hibernacula previously identified as members of Pseudeurotium are determined to belong to the genus Leuconeurospora, which is widespread, especially in colder regions. Teberdinia hygrophila is transferred to Pseudeurotium as Pseudeurotium hygrophilum, comb. nov., in accordance with the one name per fungus system of classification, and two additional combinations are made in Pseudogymnoascus including Pseudogymnoascus carnis and Pseudogymnoascus pannorum. Additional sampling from other regions of the world is needed to better understand the evolution and biogeography of this important and diverse group of fungi.

The emerging wildlife disease white-nose syndrome is causing widespread mortality in hibernating North American bats. White-nose syndrome occurs when the fungus Geomyces destructans infects the living skin of bats during hibernation, but links between infection and mortality are underexplored. We analyzed blood from hibernating bats and compared blood electrolyte levels to wing damage caused by the fungus. Sodium and chloride tended to decrease as wing damage increased in severity. Depletion of these electrolytes suggests that infected bats may become hypotonically dehydrated during winter. Although bats regularly arouse from hibernation to drink during winter, water available in hibernacula may not contain sufficient electrolytes to offset winter losses caused by disease. Damage to bat wings from G. destructans may cause life-threatening electrolyte imbalances.

The fungus Geomyces destructans is the causative agent of white-nose syndrome (WNS), a disease that has killed millions of North American hibernating bats. We describe a real-time TaqMan PCR test that detects DNA from G. destructans by targeting a portion of the multicopy intergenic spacer region of the rRNA gene complex. The test is highly sensitive, consistently detecting as little as 3.3 fg genomic DNA from G. destructans. The real-time PCR test specifically amplified genomic DNA from G. destructans but did not amplify target sequence from 54 closely related fungal isolates (including 43 Geomyces spp. isolates) associated with bats. The test was qualified further by analyzing DNA extracted from 91 bat wing skin samples, and PCR results matched histopathology findings. These data indicate the real-time TaqMan PCR method described herein is a sensitive, specific and rapid test to detect DNA from G. destructans and provides a valuable tool for WNS diagnostics and research.

Increases in anthropogenic movement have led to a rise in pathogen introductions and the emergence of infectious diseases in naive host communities worldwide. We combined empirical data and mathematical models to examine changes in disease dynamics in little brown bat ( Myotis lucifugus ) populations following the introduction of the emerging fungal pathogen Pseudogymnoascus destructans , which causes the disease white-nose syndrome. We found that infection intensity was much lower in persisting populations than in declining populations where the fungus has recently invaded. Fitted models indicate that this is most consistent with a reduction in the growth rate of the pathogen when fungal loads become high. The data are inconsistent with the evolution of tolerance or an overall reduced pathogen growth rate that might be caused by environmental factors. The existence of resistance in some persisting populations of little brown bats offers a glimmer of hope that a precipitously declining species will persist in the face of this deadly pathogen. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences’.

White nose syndrome, caused by Geomyces destructans, has killed more than 5 million cave hibernating bats in eastern North America. During hibernation, the lack of inflammatory cell recruitment at the site of fungal infection and erosion is consistent with a temperature-induced inhibition of immune cell trafficking. This immune suppression allows G. destructans to colonize and erode the skin of wings, ears and muzzle of bat hosts unchecked. Yet, paradoxically, within weeks of emergence from hibernation an intense neutrophilic inflammatory response to G. destructans is generated, causing severe pathology that can contribute to death. We hypothesize that the sudden reversal of immune suppression in bats upon the return to euthermia leads to a form of immune reconstitution inflammatory syndrome (IRIS). IRIS was first described in HIV-infected humans with low helper T lymphocyte counts and bacterial or fungal opportunistic infections. IRIS is a paradoxical and rapid worsening of symptoms in immune compromised humans upon restoration of immunity in the face of an ongoing infectious process. In humans with HIV, the restoration of adaptive immunity following suppression of HIV replication with anti-retroviral therapy (ART) can trigger severe immune-mediated tissue damage that can result in death. We propose that the sudden restoration of immune responses in bats infected with G. destructans results in an IRIS-like dysregulated immune response that causes the post-emergent pathology.

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.

White-nose syndrome, associated with the fungal skin infection geomycosis, caused regional population collapse in bats in North America. Our results, based on histopathology, show the presence of white-nose syndrome in Europe. Dermatohistopathology on two bats (Myotis myotis) found dead in March 2010 with geomycosis in the Czech Republic had characteristics resembling Geomyces destructans infection in bats confirmed with white-nose syndrome in US hibernacula. In addition, a live M. myotis, biopsied for histopathology during hibernation in April 2011, had typical fungal infection with cupping erosion and invasion of muzzle skin diagnostic for white-nose syndrome and conidiospores identical to G. destructans that were genetically confirmed as G. destructans.

White-nose syndrome (WNS) is a newly emergent disease that potentially threatens all temperate bat species. A recently identified fungus, Geomyces destructans, is the most likely causative agent of this disease. Until 2009, WNS and G. destructans were exclusively known from North America, but recent studies have confirmed this fungus is also present in Europe. We assembled an international WNS consortium of 67 scientists from 29 countries and identified the most important research and conservation priorities to assess the risk of WNS to European bats. Here, we review what is known about WNS and G. destructans and detail the conservation and research recommendations aimed at understanding and containing this emerging infectious disease.

Unlike bats in North America, bats in Europe are not killed by this fungus., White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

White-nose syndrome is caused by the fungus Geomyces destructans and is responsible for the deaths of >1,000,000 bats since 2006. This disease and fungus had been restricted to the northeastern United States. We detected this fungus in a bat in France and assessed the implications of this finding.

White-nose syndrome (WNS) is an emerging disease causing massive mortality of hibernating bats in the northeastern United States. At hibernacula, bats affected with WNS typically exhibit growth of a white psychrophylic fungus (Geomyces destructans) on the nose, wings and ears; many individuals seem to prematurely die of starvation owing to depleted fat reserves. Conspicuous scarring and necrosis of the wings on WNS-affected bats that survive hibernation may have lasting consequences for survival and reproductive success during the active season. We monitored two maternity colonies of little brown myotis, Myotis lucifugus, in Massachusetts and New Hampshire from 14 May to 8 August 2008 to assess body conditions after expected exposure to WNS over the previous winter. We developed a 4-point wing damage index (WDI = 0 to 3) to assess the incidence and severity of wing damage in the months following emergence from hibernation. Severe wing damage was observed up to 4 June and moderate damage was observed through 9 July. Light wing damage was observed on both adult and juvenile bats throughout the study period, but was not exclusively attributed to WNS. The most severe wing damage was associated with a lower body mass index which may reflect reduced foraging success. Overall, reproductive rate was 85.1% in 2008; slightly lower than reported in previous studies. The incidence, timing, and geographic range of wing damage observed on little brown myotis in 2008 correspond to the occurrence of WNS at hibernacula. Monitoring wing conditions of affected and healthy bats will be important tool for assessing the spread of this disease and for establishing baseline data for unaffected bats. The simple scale we propose should be useful for monitoring wing conditions in any bat species.

We describe and illustrate the new species Geomyces destructans. Bats infected with this fungus present with powdery conidia and hyphae on their muzzles, wing membranes, and/or pinnae, leading to description of the accompanying disease as white-nose syndrome, a cause of widespread mortality among hibernating bats in the northeastern US. Based on rRNA gene sequence (ITS and SSU) characters the fungus is placed in the genus Geomyces, yet its distinctive asymmetrically curved conidia are unlike those of any described Geomyces species.

Background White-nose syndrome (WNS) has devastated bat populations in North America, with millions of bats dead. WNS is associated with physiological changes in hibernating bats, leading to increased arousals from hibernation and premature consumption of fat reserves. However, there is evidence of surviving populations of little brown myotis (Myotis lucifugus) close to where the fungus was first detected nearly ten years ago. Results We examined the hibernation patterns of a surviving population of little brown myotis and compared them to patterns in populations before the arrival of WNS and populations at the peak of WNS mortality. Despite infection with Pseudogymnoascus destructans, the causative fungal agent, the remnant population displayed less frequent arousals from torpor and lower torpid body temperatures than bats that died from WNS during the peak of mortality. The hibernation patterns of the remnant population resembled pre-WNS patterns with some modifications. Conclusions These data show that remnant populations of little brown myotis do not experience the increase in periodic arousals from hibernation typified by bats dying from WNS, despite the presence of the fungal pathogen on their skin. These patterns may reflect the use of colder hibernacula microclimates by WNS survivors, and/or may reflect differences in how these bats respond to the disease. Electronic supplementary material The online version of this article (doi:10.1186/s12983-016-0143-3) contains supplementary material, which is available to authorized users.

To the Editor: Emerging infectious diseases have caused catastrophic declines in wildlife populations, and the introductions of many pathogen have been linked to increases in global trade and travel (1). Mapping the distribution of pathogens is necessary to identify species and populations at risk and identify sources of pathogen spillover and introduction. Once pathogen distributions are known, management actions can be taken to reduce the risk for future global spread (2). Bats with symptoms of white-nose syndrome (WNS) were first detected in the United States in 2006, and the disease has subsequently caused precipitous declines in temperate bat populations across eastern North America (3,4). Pseudogymnoascus destructans, the causative agent of WNS, is a cold-growing fungus that infects bats’ skin during hibernation, leading to more frequent arousals from torpor and death (3). P. destructans is widespread throughout Europe (5), but, to our knowledge, its presence in Asia has not been documented. We sampled bats and hibernacula surfaces (cave walls and ceilings) across northeastern China during 2 visits (June–July 2014 and March 2015) using a previously described swab-sampling technique (6). Bats were captured inside caves and at their entrances. DNA was extracted from samples by using a modified QIAGEN DNeasy blood and tissue kit (QIAGEN, Valencia, CA, USA) and tested in duplicate for the presence of P. destructans with a quantitative real-time PCR (qPCR) (6,7). In the summer of 2014 and winter of 2015, we collected 385 samples from hibernacula surfaces at 12 sites in 3 provinces and 1 municipality (Figure, panel A) and 215 samples from 9 species of bats at 10 sites (summer: Rhinolophus ferrumequinum, Rhinolophus pusillus, Myotis adversus, Myotis macrodactylus, Myotis pilosus, Myotis chinensis, Murina usseriensis; winter: R. ferrumequinum, Murina leucogaster, Myotis petax). During the summer, P. destructans was widely distributed across the study region with positive samples (determined on the basis of qPCR results) obtained from cave surfaces at 9 of 12 sites and from bats at 2 of the 9 sites where bats were sampled (Figure, panel A). Figure A) Distribution of Pseudogymnoascus destructans in cave environments during summer at 9 sites in northeastern China. Pie charts show the prevalence (red indicates fraction of positive samples) of P. destructans, and the size of pie graphs indicates the ... Prevalence of P. destructans was low during summer in the environment (mean prevalence across sites 0.06 ± 0.03) and in bats. Bats of 3 species tested positive for P. destructans in the summer: M. macrodactylus (1/10), M. chinensis (1/1), and M. ussuriensis (1/1). P. destructans was not detected in bats of 4 other species, of which >20 individual animals of each species were sampled (R. ferrumequinum, R. pusillus, M. pilosus, and M. adversus). The low prevalence of P. destructans in bats and on hibernacula surfaces in China during the summer was similar to comparable results from studies in North America (6). In winter, prevalence at the 2 sites we revisited was much higher; 75% of 85 samples from 3 species tested positive, including samples from 16/17 M. petax bats. We also detected P. destructans in bats from 2 additional species (R. ferrumequinum [11/19 bats] and M. leucogaster [11/16 bats]). In addition, during March 2015, we observed visual evidence of P. destructans in bats (M. petax; Figure, panel C) and obtained 2 fungal cultures from swab specimens taken from these bats. To isolate P. destructans from these samples, we plated swab specimens from visibly infected bats on Sabouraud dextrose agar at 10°C. We identified potential P. destructans isolates on the basis of morphologic characteristics. DNA was then extracted from 2 suspected fungal cultures and tested for P. destructans by qPCR, as previously described. To further confirm the presence of P. destructans, we prepared the fungal isolates for Sanger sequencing (Technical Appendix). The 600-nt amplification products from these 2 isolates were sequenced and found to be 100% identical to the P. destructans rRNA gene region targeted for amplification. In addition, using BLAST (http://www.ncbi.nlm.nih.gov/blast.cgi), we found that sequences were a 100% match with isolates from Europe (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"GQ489024","term_id":"284944064","term_text":"GQ489024"}}GQ489024) and North America (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"EU884924","term_id":"211905147","term_text":"EU884924"}}EU884924). This result confirms that the same species of fungus occurs on all 3 continents. We also obtained wing biopsy punches from these bats and found lesions characteristic of WNS by histopathologic examination (Figure, panel B; Technical Appendix). The occurrence of P. destructans at most sites sampled indicates that this pathogen is widespread in eastern Asia (Figure, panel A). The presence of P. destructans in bats from 6 species in China and on bats in 13 species in Europe (8) confirms the generalist nature of this fungus and suggests that it may occur throughout Eurasia (Figure, panel D). Decontamination and restrictions on the use of equipment that has been used in caves in Asia would help reduce the probability of introducing P. destructans to uninfected bat populations (e.g., western North America, New Zealand, southern Australia, and temperate areas of South America). These measures would also reduce the risk of introducing new strains of P. destructans to regions where bats are already infected (e.g., eastern North America and Europe). These measures are necessary to prevent the devastating effects this pathogen has had on bats in North America and would help maintain the ecosystem services that bats provide (9,10). Technical Appendix: The Technical Appendix describes the DNA sequencing of fungal isolates to confirm the presence of Pseudogymnoascus destructans and histologic examination of bat fungal lesions. Click here to view.(238K, pdf)

In this study, the complete mitochondrial genome of the White-Nose Syndrome pathogen, Pseudogymnoascus destructans (=Geomyces destructans), is sequenced. The circular mitochondrial genome is 32,181 bp long and encodes 13 standard proteins, 2 ribosomal RNA subunits, and 27 tRNAs. The genome contains two introns located within the cytochrome c oxidase subunit 1 gene (cox1) and the large ribosomal RNA subunit (rrnl), with each intron encoding one gene, orf110 and rps3, respectively. Phylogenetic analysis of the concatenated mitochondrial protein-coding genes of P. destructans and close representatives in Leotiomycetes showed that P. destructans was closely related to Pseudogymnoascus pannorum, consistent with nuclear genes.

To the Editor: Bat geomycosis (white nose syndrome) is caused by the psychrophilic fungus Geomyces destructans, which has rapidly spread in the United States and Canada since it was first reported from Albany, New York (1,2). In 2011, a single genotype of G. destructans was found in bats with geomycosis in different parts of New York (3). The findings raised the possibility of clonal spread of a new pathogen with serious implications for the survival of the affected bat populations (4). To provide information for devising conservation measures, we explored whether this emerging infectious disease is caused by a novel pathogen (5). To do so, we genotyped G. destructans isolates from the midwestern and southern United States. During 2010 and 2011, a total of 11 cultures of G. destructans were isolated and identified: 1 each from Pennsylvania and Ohio, 3 from North Carolina, and 6 from West Virginia (Figure). The cultures came from 8 little brown bats (Myotis lucifugus) and 3 tri-colored bats (Perimyotis subflavus). Two recent G. destructans isolates from New York and 1 G. pannorum isolate were included as controls. Genomic DNA was prepared from fungal growth by the conventional glass bead treatment, phenol–chloroform extraction, and ethanol precipitation. PCR amplifications of 8 G. destructans gene fragments (ALR, Bpntase, DHC1, GPHN, PCS, POB3, SRP72, and VPS13) were performed as described (3). The amplicons were sequenced and nucleotides were aligned by Sequencher 4.8 (www.genecodes.com); phylogenetic analyses were done using PAUP*4.0 software (www.sinauer.com). Figure A) Consensus maximum-parsimony tree of 8 concatenated gene fragments of Geomyces destructans. Data were derived from 13 G. destructans test isolates. G. destructans M1379 and G. pannorum M1378 were used as controls in this study; they were described in ... A total of 4,722 nt sequences were obtained from 8 gene fragments of 13 G. destructans isolates (GenBank accession nos. {"type":"entrez-nucleotide-range","attrs":{"text":"JQ029780-JQ029883","start_term":"JQ029780","end_term":"JQ029883","start_term_id":"380040511","end_term_id":"380040717"}}JQ029780-JQ029883) and 1 G. pannorum isolate (GenBank accession nos. {"type":"entrez-nucleotide","attrs":{"text":"HQ834330","term_id":"386776025","term_text":"HQ834330"}}HQ834330, {"type":"entrez-nucleotide","attrs":{"text":"HQ834347","term_id":"386776059","term_text":"HQ834347"}}HQ834347, {"type":"entrez-nucleotide","attrs":{"text":"HQ834364","term_id":"386776093","term_text":"HQ834364"}}HQ834364, {"type":"entrez-nucleotide","attrs":{"text":"HQ834381","term_id":"386776127","term_text":"HQ834381"}}HQ834381, {"type":"entrez-nucleotide","attrs":{"text":"HQ834398","term_id":"386776161","term_text":"HQ834398"}}HQ834398, {"type":"entrez-nucleotide","attrs":{"text":"HQ834415","term_id":"386776195","term_text":"HQ834415"}}HQ834415, {"type":"entrez-nucleotide","attrs":{"text":"HQ834432","term_id":"386776229","term_text":"HQ834432"}}HQ834432, and {"type":"entrez-nucleotide","attrs":{"text":"HQ834449","term_id":"386776263","term_text":"HQ834449"}}HQ834449). Multiple alignments of these sequences showed 100% identity, and the aligned nucleotides matched perfectly with those of earlier G. destructans sequences for the same gene fragments analyzed from New York isolates (3). The nucleotide alignments of 8 sequences showed differences from those obtained from the closely related fungus, G. pannorum. Maximum-parsimony trees were generated by using sequences from each gene fragment. These trees showed a single clade of G. destructans strains distinct from G. pannorum; similar topologies were obtained when different phylogenetics methods were used for analysis (details not shown). A consensus maximum-parsimony tree derived from the 8 concatenated gene fragments also showed a single clade of G. destructans isolates from New York and the midwestern and southern United States (Figure). The data obtained in this study strongly indicate further clonal spread of G. destructans from its origin near Albany, New York. The locations in which G. destructans was detected in the current study were spread across 5 states, which were >800 miles from Albany. The test isolates were compared with a New York isolate from 2008, which provided a 4-year temporal variation in our sampling. Bats of 2 species were positive for G. desctructans in the current samples, and they yielded the same G. destructans genotype. Thus, there is evidence for host-independent spread of a single clone of G. destructans. These data would support the novel-pathogen hypothesis for the origin of bat geomycosis (5). However, these conclusions are based on limited sampling because isolations of G. destructans from affected bats are uncommon. The demonstration of pure fungal culture in the affected animals is still not the standard for geomycosis diagnostics, and most geomycosis is confirmed by bat morphologic appearance or histopathologic examination. Additionally, our phylogenetics analyses were limited to ≈5 kbp of fungal genomes, which could lead to sampling bias (3). Ideally, a large number of G. destructans isolates, including isolates from Europe, and additional polymorphic markers would be needed to determine the novel or local origin of this pathogen (6,7). The environmental factors that led to introduction or reemergence of G. destructans in mines and caves remain unknown, and their contribution in the spread of the fungus through air, water, and soil is yet to be determined (8). Although no direct evidence has emerged, a role for anthropomorphic activities (occupational or recreational) in this spread is a distinct possibility (9). We provide genetic evidence for further spread of a single genotype of G. destructans from Albany, New York, to locations in the midwestern and southern United States. Experimental transmission of geomycosis from infected bats to healthy bats by direct contact has recently been confirmed (10). Therefore, G. destructans might be rapidly spreading along summer and winter migration routes of bats, which present ample opportunities for mixing of healthy and diseased animals.

White-nose syndrome (WNS) has caused recent catastrophic declines among multiple species of bats in eastern North America. The disease's name derives from a visually apparent white growth of the newly discovered fungus Geomyces destructans on the skin (including the muzzle) of hibernating bats. Colonization of skin by this fungus is associated with characteristic cutaneous lesions that are the only consistent pathological finding related to WNS. However, the role of G. destructans in WNS remains controversial because evidence to implicate the fungus as the primary cause of this disease is lacking. The debate is fuelled, in part, by the assumption that fungal infections in mammals are most commonly associated with immune system dysfunction. Additionally, the recent discovery that G. destructans commonly colonizes the skin of bats of Europe, where no unusual bat mortality events have been reported, has generated further speculation that the fungus is an opportunistic pathogen and that other unidentified factors are the primary cause of WNS. Here we demonstrate that exposure of healthy little brown bats (Myotis lucifugus) to pure cultures of G. destructans causes WNS. Live G. destructans was subsequently cultured from diseased bats, successfully fulfilling established criteria for the determination of G. destructans as a primary pathogen. We also confirmed that WNS can be transmitted from infected bats to healthy bats through direct contact. Our results provide the first direct evidence that G. destructans is the causal agent of WNS and that the recent emergence of WNS in North America may represent translocation of the fungus to a region with a naive population of animals. Demonstration of causality is an instrumental step in elucidating the pathogenesis and epidemiology of WNS and in guiding management actions to preserve bat populations against the novel threat posed by this devastating infectious disease.

Background The physiological effects of white-nose syndrome (WNS) in hibernating bats and ultimate causes of mortality from infection with Pseudogymnoascus (formerly Geomyces) destructans are not fully understood. Increased frequency of arousal from torpor described among hibernating bats with late-stage WNS is thought to accelerate depletion of fat reserves, but the physiological mechanisms that lead to these alterations in hibernation behavior have not been elucidated. We used the doubly labeled water (DLW) method and clinical chemistry to evaluate energy use, body composition changes, and blood chemistry perturbations in hibernating little brown bats (Myotis lucifugus) experimentally infected with P. destructans to better understand the physiological processes that underlie mortality from WNS. Results These data indicated that fat energy utilization, as demonstrated by changes in body composition, was two-fold higher for bats with WNS compared to negative controls. These differences were apparent in early stages of infection when torpor-arousal patterns were equivalent between infected and non-infected animals, suggesting that P. destructans has complex physiological impacts on its host prior to onset of clinical signs indicative of late-stage infections. Additionally, bats with mild to moderate skin lesions associated with early-stage WNS demonstrated a chronic respiratory acidosis characterized by significantly elevated dissolved carbon dioxide, acidemia, and elevated bicarbonate. Potassium concentrations were also significantly higher among infected bats, but sodium, chloride, and other hydration parameters were equivalent to controls. Conclusions Integrating these novel findings on the physiological changes that occur in early-stage WNS with those previously documented in late-stage infections, we propose a multi-stage disease progression model that mechanistically describes the pathologic and physiologic effects underlying mortality of WNS in hibernating bats. This model identifies testable hypotheses for better understanding this disease, knowledge that will be critical for defining effective disease mitigation strategies aimed at reducing morbidity and mortality that results from WNS. Electronic supplementary material The online version of this article (doi:10.1186/s12899-014-0010-4) contains supplementary material, which is available to authorized users.

White-nose Syndrome (WNS) is the primary cause of over-winter mortality for little brown (Myotis lucifugus), northern (Myotis septentrionalis), and tricolored (Perimyotis subflavus) bats, and is due to cutaneous infection with the fungus Pseudogymnoascus (Geomyces) destructans (Pd). Cutaneous infection with P. destructans disrupts torpor patterns, which is thought to lead to a premature depletion of body fat reserve. Field studies were conducted at 3 WNS-affected hibernation sites to determine if big brown bats (Eptesicus fuscus) are resistant to Pd. Radio telemetry studies were conducted during 2 winters to determine the torpor patterns of 23 free-ranging E. fuscus hibernating at a site where Pd occurs. The body fat contents of free-ranging E. fuscus and M. lucifugus during hibernation at 2 different WNS-affected sites were also determined. The numbers of bats hibernating at the same site was determined during both: a) 4–7 years prior to the arrival of Pd, and, b) 2–3 years after it first appeared at this site. The torpor bouts of big brown bats hibernating at a WNS-affected site were not significantly different in length from those previously reported for this species. The mean body fat content of E. fuscus in February was nearly twice that of M. lucifugus hibernating at the same WNS-affected sites during this month. The number of M. lucifugus hibernating at one site decreased by 99.6% after P. destructans first appeared, whereas the number of E. fuscus hibernating there actually increased by 43% during the same period. None of the E. fuscus collected during this study had any visible fungal growth or lesions on their skin, whereas virtually all the M. lucifugus collected had visible fungal growth on their wings, muzzle, and ears. These findings indicate that big brown bats are resistant to WNS.

Host traits and phylogeny can determine infection risk by driving pathogen transmission and its ability to infect new hosts. Predicting such risks is critical when designing disease mitigation strategies, and especially as regards wildlife, where intensive management is often advocated or prevented by economic and/or practical reasons. We investigated Pseudogymnoascus [Geomyces] destructans infection, the cause of white-nose syndrome (WNS), in relation to chiropteran ecology, behaviour and phylogenetics. While this fungus has caused devastating declines in North American bat populations, there have been no apparent population changes attributable to the disease in Europe. We screened 276 bats of 15 species from hibernacula in the Czech Republic over 2012 and 2013, and provided histopathological evidence for 11 European species positive for WNS. With the exception of Myotis myotis, the other ten species are all new reports for WNS in Europe. Of these, M. emarginatus, Eptesicus nilssonii, Rhinolophus hipposideros, Barbastella barbastellus and Plecotus auritus are new to the list of P. destructans-infected bat species. While the infected species are all statistically phylogenetically related, WNS affects bats from two suborders. These are ecologically diverse and adopt a wide range of hibernating strategies. Occurrence of WNS in distantly related bat species with diverse ecology suggests that the pathogen may be a generalist and that all bats hibernating within the distribution range of P. destructans may be at risk of infection.

The psychrophilic fungus Pseudogymnoascus destructans (formerly known as Geomyces destructans) is considered the etiological agent of white-nose disease (WND), an emerging disease which affects bats during their hibernation period. This disease is clinically characterized by the growth of a white fungus on muzzle, ears, and wings’ membranes of affected bats. This infection caused the death of several million bats in North America. Conversely, European bats show no evidence of significant mortality occurrences associated with P. destructans colonization. This fungus has been isolated from bats in at least 15 European countries since 2008, but was never before reported in the Iberian Peninsula. This study describes the first case report of P. destructans colonization in bats from Portugal. We isolated P. destructans from three hibernating Myotis blythii (lesser mouse-eared bat) with visual signs of P. destructans colonization, during a routine visit to a mine located in the Tras-os-Montes region, Northern Portugal. M. blythii is one of the rarest bat species in Europe, classified as critically endangered in Portugal. P. destructans was obtained from at least three different parts of the body of each specimen analyzed. The identification of the respective fungal isolates was based on the macroscopic and microscopic characterization of the cultures and confirmed by PCR-based analysis. All nucleotide sequences obtained showed 100 % identity with previous data reported for P. destructans. This new finding improves the current knowledge about the European distribution of P. destructans, which is of great interest for forthcoming studies on the fungus dispersion and impact among bat populations at regional and/or global level.

We report the draft genome sequences of Geomyces pannorum sensu lato and Geomyces (Pseudogymnoascus) destructans . G. pannorum has a larger proteome than G. destructans , containing more proteins with ascribed enzymatic functions. This dichotomy in the genomes of related psychrophilic fungi is a valuable target for defining their distinct saprobic and pathogenic attributes.

White-nose syndrome (WNS) is an emerging disease of hibernating bats caused by the recently described fungus Geomyces destructans . First isolated in 2008, the origins of this fungus in North America and its ability to persist in the environment remain undefined. To investigate the correlation between manifestation of WNS and distribution of G. destructans in the United States, we analyzed sediment samples collected from 55 bat hibernacula (caves and mines) both within and outside the known range of WNS using a newly developed real-time PCR assay. Geomyces destructans was detected in 17 of 21 sites within the known range of WNS at the time when the samples were collected; the fungus was not found in 28 sites beyond the known range of the disease at the time when environmental samples were collected. These data indicate that the distribution of G. destructans is correlated with disease in hibernating bats and support the hypothesis that the fungus is likely an exotic species in North America. Additionally, we examined whether G. destructans persists in infested bat hibernacula when bats are absent. Sediment samples were collected from 14 WNS-positive hibernacula, and the samples were screened for viable fungus by using a culture technique. Viable G. destructans was cultivated from 7 of the 14 sites sampled during late summer, when bats were no longer in hibernation, suggesting that the fungus can persist in the environment in the absence of bat hosts for long periods of time.

White-nose syndrome (WNS) is an emergent disease estimated to have killed over five million North American bats. Caused by the psychrophilic fungus Geomyces destructans, WNS specifically affects bats during hibernation. We describe temperature-dependent growth performance and morphology for six independent isolates of G. destructans from North America and Europe. Thermal performance curves for all isolates displayed an intermediate peak with rapid decline in performance above the peak. Optimal temperatures for growth were between 12.5 and 15.8°C, and the upper critical temperature for growth was between 19.0 and 19.8°C. Growth rates varied across isolates, irrespective of geographic origin, and above 12°C all isolates displayed atypical morphology that may have implications for proliferation of the fungus. This study demonstrates that small variations in temperature, consistent with those inherent of bat hibernacula, affect growth performance and physiology of G. destructans, which may influence temperature-dependent progression and severity of WNS in wild bats.

Disease has caused striking declines in wildlife and threatens numerous species with extinction. Theory suggests that the ecology and density-dependence of transmission dynamics can determine the probability of disease-caused extinction, but few empirical studies have simultaneously examined multiple factors influencing disease impact. We show, in hibernating bats infected with Geomyces destructans, that impacts of disease on solitary species were lower in smaller populations, whereas in socially gregarious species declines were equally severe in populations spanning four orders of magnitude. However, as these gregarious species declined, we observed decreases in social group size that reduced the likelihood of extinction. In addition, disease impacts in these species increased with humidity and temperature such that the coldest and driest roosts provided initial refuge from disease. These results expand our theoretical framework and provide an empirical basis for determining which host species are likely to be driven extinct while management action is still possible.

Synopsis White-nose syndrome (WNS) has caused alarming declines of North American bat populations in the 5 years since its discovery. Affected bats appear to starve during hibernation, possibly because of disruption of normal cycles of torpor and arousal. The importance of hydration state and evaporative water loss (EWL) for influencing the duration of torpor bouts in hibernating mammals recently led to ‘‘the dehydration hypothesis,’’ that cutaneous infection of the wing membranes of bats with the fungus Geomyces destructans causes dehydration which in turn, increases arousal frequency during hibernation. This hypothesis predicts that uninfected individuals of species most susceptible to WNS, like little brown bats (Myotis lucifugus), exhibit high rates of EWL compared to less susceptible species. We tested the feasibility of this prediction using data from the literature and new data quantifying EWL in Natterer’s bats (Myotis nattereri), a species that is, like other European bats, sympatric with G. destructans but does not appear to suffer significant mortality from WNS. We found that little brown bats exhibited significantly higher rates of normothermic EWL than did other bat species for which comparable EWL data are available. We also found that Natterer’s bats exhibited significantly lower rates of EWL, in both wet and dry air, compared with values predicted for little brown bats exposed to identical relative humidity (RH). We used a population model to show that the increase in EWL required to cause the pattern of mortality observed for WNS-affected little brown bats was small, equivalent to a solitary bat hibernating exposed to RH of � 95%, or clusters hibernating in � 87% RH, as opposed to typical near-saturation conditions. Both of these results suggest the dehydration hypothesis is plausible and worth pursuing as a possible explanation for mortality of bats from WNS.

BackgroundThe dramatic mass mortalities amongst hibernating bats in Northeastern America caused by "white nose-syndrome" (WNS) continue to threaten populations of different bat species. The cold-loving fungus, Geomyces destructans, is the most likely causative agent leading to extensive destruction of the skin, particularly the wing membranes. Recent investigations in Europe confirmed the presence of the fungus G. destructans without associated mass mortality in hibernating bats in six countries but its distribution remains poorly known.Methodology/principal findingsWe collected data on the presence of bats with white fungal growth in 12 countries in Europe between 2003 and 2010 and conducted morphological and genetic analysis to confirm the identity of the fungus as Geomyces destructans. Our results demonstrate the presence of the fungus in eight countries spanning over 2000 km from West to East and provide compelling photographic evidence for its presence in another four countries including Romania, and Turkey. Furthermore, matching prevalence data of a hibernaculum monitored over two consecutive years with data from across Europe show that the temporal occurrence of the fungus, which first becomes visible around February, peaks in March but can still be seen in some torpid bats in May or June, is strikingly similar throughout Europe. Finally, we isolated and cultured G. destructans from a cave wall adjacent to a bat with fungal growth.Conclusions/significanceG. destructans is widely found over large areas of the European continent without associated mass mortalities in bats, suggesting that the fungus is native to Europe. The characterisation of the temporal variation in G. destructans growth on bats provides reference data for studying the spatio-temporal dynamic of the fungus. Finally, the presence of G. destructans spores on cave walls suggests that hibernacula could act as passive vectors and/or reservoirs for G. destructans and therefore, might play an important role in the transmission process.

BackgroundWhite-nose syndrome is a disease of hibernating insectivorous bats associated with the fungus Geomyces destructans. It first appeared in North America in 2006, where over a million bats died since then. In Europe, G. destructans was first identified in France in 2009. Its distribution, infection dynamics, and effects on hibernating bats in Europe are largely unknown.Methodology/principal findingsWe screened hibernacula in the Czech Republic and Slovakia for the presence of the fungus during the winter seasons of 2008/2009 and 2009/2010. In winter 2009/2010, we found infected bats in 76 out of 98 surveyed sites, in which the majority had been previously negative. A photographic record of over 6000 hibernating bats, taken since 1994, revealed bats with fungal growths since 1995; however, the incidence of such bats increased in Myotis myotis from 2% in 2007 to 14% by 2010. Microscopic, cultivation and molecular genetic evaluations confirmed the identity of the recently sampled fungus as G. destructans, and demonstrated its continuous distribution in the studied area. At the end of the hibernation season we recorded pathologic changes in the skin of the affected bats, from which the fungus was isolated. We registered no mass mortality caused by the fungus, and the recorded population decline in the last two years of the most affected species, M. myotis, is within the population trend prediction interval.Conclusions/significanceG. destructans was found to be widespread in the Czech Republic and Slovakia, with an epizootic incidence in bats during the most recent years. Further development of the situation urgently requires a detailed pan-European monitoring scheme.

BackgroundMassive die-offs of little brown bats (Myotis lucifugus) have been occurring since 2006 in hibernation sites around Albany, New York, and this problem has spread to other States in the Northeastern United States. White cottony fungal growth is seen on the snouts of affected animals, a prominent sign of White Nose Syndrome (WNS). A previous report described the involvement of the fungus Geomyces destructans in WNS, but an identical fungus was recently isolated in France from a bat that was evidently healthy. The fungus has been recovered sparsely despite plentiful availability of afflicted animals.Methodology/principal findingsWe have investigated 100 bat and environmental samples from eight affected sites in 2008. Our findings provide strong evidence for an etiologic role of G. destructans in bat WNS. (i) Direct smears from bat snouts, Periodic Acid Schiff-stained tissue sections from infected tissues, and scanning electron micrographs of bat tissues all showed fungal structures similar to those of G. destructans. (ii) G. destructans DNA was directly amplified from infected bat tissues, (iii) Isolations of G. destructans in cultures from infected bat tissues showed 100% DNA match with the fungus present in positive tissue samples. (iv) RAPD patterns for all G. destructans cultures isolated from two sites were indistinguishable. (v) The fungal isolates showed psychrophilic growth. (vi) We identified in vitro proteolytic activities suggestive of known fungal pathogenic traits in G. destructans.Conclusions/significanceFurther studies are needed to understand whether G. destructans WNS is a symptom or a trigger for bat mass mortality. The availability of well-characterized G. destructans strains should promote an understanding of bat-fungus relationships, and should aid in the screening of biological and chemical control agents.

White-nose syndrome is devastating North American bat populations but we lack basic information on disease mechanisms. Altered blood physiology owing to epidermal invasion by the fungal pathogen Geomyces destructans ( Gd ) has been hypothesized as a cause of disrupted torpor patterns of affected hibernating bats, leading to mortality. Here, we present data on blood electrolyte concentration, haematology and acid–base balance of hibernating little brown bats, Myotis lucifugus , following experimental inoculation with Gd . Compared with controls, infected bats showed electrolyte depletion (i.e. lower plasma sodium), changes in haematology (i.e. increased haematocrit and decreased glucose) and disrupted acid–base balance (i.e. lower CO 2 partial pressure and bicarbonate). These findings indicate hypotonic dehydration, hypovolaemia and metabolic acidosis. We propose a mechanistic model linking tissue damage to altered homeostasis and morbidity/mortality.

White-nose syndrome (WNS), an emerging infectious disease that has killed over 5.5 million hibernating bats, is named for the causative agent, a white fungus (Geomyces destructans (Gd)) that invades the skin of torpid bats. During hibernation, arousals to warm (euthermic) body temperatures are normal but deplete fat stores. Temperature-sensitive dataloggers were attached to the backs of 504 free-ranging little brown bats (Myotis lucifugus) in hibernacula located throughout the northeastern USA. Dataloggers were retrieved at the end of the hibernation season and complete profiles of skin temperature data were available from 83 bats, which were categorized as: (1) unaffected, (2) WNS-affected but alive at time of datalogger removal, or (3) WNS-affected but found dead at time of datalogger removal. Histological confirmation of WNS severity (as indexed by degree of fungal infection) as well as confirmation of presence/absence of DNA from Gd by PCR was determined for 26 animals. We demonstrated that WNS-affected bats aroused to euthermic body temperatures more frequently than unaffected bats, likely contributing to subsequent mortality. Within the subset of WNS-affected bats that were found dead at the time of datalogger removal, the number of arousal bouts since datalogger attachment significantly predicted date of death. Additionally, the severity of cutaneous Gd infection correlated with the number of arousal episodes from torpor during hibernation. Thus, increased frequency of arousal from torpor likely contributes to WNS-associated mortality, but the question of how Gd infection induces increased arousals remains unanswered.

White-nose syndrome (WNS) is a condition associated with an unprecedented bat mortality event in the northeastern United States. Since the winter of 2006*2007, bat declines exceeding 75% have been observed at surveyed hibernacula. Affected bats often present with visually striking white fungal growth on their muzzles, ears, and/or wing membranes. Direct microscopy and culture analyses demonstrated that the skin of WNS-affected bats is colonized by a psychro-philic fungus that is phylogenetically related to Geomyces spp. but with a conidial morphology distinct from characterized members of this genus. This report characterizes the cutaneous fungal infection associated with WNS.

White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians.