ORCID Profile
0000-0002-0985-8607
Current Organisation
University of Winnipeg
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Animal Physiological Ecology | Wildlife and Habitat Management | Environmental Science and Management | Conservation and Biodiversity
Control of Pests, Diseases and Exotic Species not elsewhere classified | Expanding Knowledge in the Biological Sciences | Flora, Fauna and Biodiversity at Regional or Larger Scales |
Publisher: University of Chicago Press
Date: 07-2015
DOI: 10.1086/681931
Publisher: The Royal Society
Date: 23-08-2013
Abstract: 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.
Publisher: Proceedings of the National Academy of Sciences
Date: 09-04-2012
Abstract: 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, in iduals 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.
Publisher: Springer Science and Business Media LLC
Date: 03-2016
DOI: 10.1007/S10393-016-1107-Y
Abstract: White-nose syndrome is caused by the fungus Pseudogymnoascus destructans and has killed millions of hibernating bats in North America but the pathophysiology of the disease remains poorly understood. Our objectives were to (1) assess non-destructive diagnostic methods for P. destructans infection compared to histopathology, the current gold-standard, and (2) to evaluate potential metrics of disease severity. We used data from three captive inoculation experiments involving 181 little brown bats (Myotis lucifugus) to compare histopathology, quantitative PCR (qPCR), and ultraviolet fluorescence as diagnostic methods of P. destructans infection. To assess disease severity, we considered two histology metrics (wing area with fungal hyphae, area of dermal necrosis), P. destructans fungal load (qPCR), ultraviolet fluorescence, and blood chemistry (hematocrit, sodium, glucose, pCO2, and bicarbonate). Quantitative PCR was most effective for early detection of P. destructans, while all three methods were comparable in severe infections. Correlations among hyphae and necrosis scores, qPCR, ultraviolet fluorescence, blood chemistry, and hibernation duration indicate a multi-stage pattern of disease. Disruptions of homeostasis occurred rapidly in late hibernation. Our results provide valuable information about the use of non-destructive techniques for monitoring, and provide novel insight into the pathophysiology of white-nose syndrome, with implications for developing and implementing potential mitigation strategies.
Publisher: Springer Science and Business Media LLC
Date: 02-2006
DOI: 10.1007/S00114-005-0063-0
Abstract: Many mammals save energy during food shortage or harsh weather using controlled reductions in body temperature and metabolism called torpor. However, torpor slows offspring growth, and reproductive in iduals are thought to avoid using it because of reduced fitness resulting from delayed offspring development. We tested this hypothesis by investigating torpor during reproduction in hoary bats (Lasiurus cinereus, Vespertilionidae) in southern Canada. We recorded deep, prolonged torpor bouts, which meet the definition for hibernation, by pregnant females. Prolonged torpor occurred during spring storms. When conditions improved females aroused and gave birth within several days. Our observations imply a fitness advantage of torpor in addition to energy conservation because reduced foetal growth rate could delay parturition until conditions are more favourable for lactation and neonatal survival.
Publisher: Public Library of Science (PLoS)
Date: 12-11-2014
Publisher: Elsevier BV
Date: 10-2011
Publisher: Springer Science and Business Media LLC
Date: 19-10-2018
DOI: 10.1038/S41598-018-33975-X
Abstract: Spillover of viruses from bats to other animals may be associated with increased contact between them, as well as increased shedding of viruses by bats. Here, we tested the prediction that little brown bats ( Myotis lucifugus ) co-infected with the M. lucifugus coronavirus ( Myl -CoV) and with Pseudogymnoascus destructans ( Pd ), the fungus that causes bat white-nose syndrome (WNS), exhibit different disease severity, viral shedding and molecular responses than bats infected with only Myl -CoV or only P. destructans . We took advantage of the natural persistence of Myl -CoV in bats that were experimentally inoculated with P. destructans in a previous study. Here, we show that the intestines of virus-infected bats that were also infected with fungus contained on average 60-fold more viral RNA than bats with virus alone. Increased viral RNA in the intestines correlated with the severity of fungus-related pathology. Additionally, the intestines of bats infected with fungus exhibited different expression of mitogen-activated protein kinase pathway and cytokine related transcripts, irrespective of viral presence. Levels of coronavirus antibodies were also higher in fungal-infected bats. Our results suggest that the systemic effects of WNS may down-regulate anti-viral responses in bats persistently infected with M. lucifugus coronavirus and increase the potential of virus shedding.
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.PHYSBEH.2014.12.013
Abstract: The emerging wildlife disease white-nose syndrome (WNS) affects both physiology and behaviour of hibernating bats. Infection with the fungal pathogen Pseudogymnoascus destructans (Pd), the first pathogen known to target torpid animals, causes an increase in arousal frequency during hibernation, and therefore premature depletion of energy stores. Infected bats also show a dramatic decrease in clustering behaviour over the winter. To investigate the interaction between disease progression and torpor expression we quantified physiological (i.e., timing of arousal, rewarming rate) and behavioural (i.e., arousal synchronisation, clustering) aspects of rewarming events over four months in little brown bats (Myotis lucifugus) experimentally inoculated with Pd. We tested two competing hypotheses: 1) Bats adjust arousal physiology adaptively to help compensate for an increase in energetically expensive arousals. This hypothesis predicts that infected bats should increase synchronisation of arousals with colony mates to benefit from social thermoregulation and/or that solitary bats will exhibit faster rewarming rates than clustered in iduals because rewarming costs fall as rewarming rate increases. 2) As for the increase in arousal frequency, changes in arousal physiology and clustering behaviour are maladaptive consequences of infection. This hypothesis predicts no effect of infection or clustering behaviour on rewarming rate and that disturbance by normothermic bats contributes to the overall increase in arousal frequency. We found that arousals of infected bats became more synchronised than those of controls as hibernation progressed but the pattern was not consistent with social thermoregulation. When a bat rewarmed from torpor, it was often followed in sequence by up to seven other bats in an arousal "cascade". Moreover, rewarming rate did not differ between infected and uninfected bats, was not affected by clustering and did not change over time. Our results support our second hypothesis and suggest that disturbance, not social thermoregulation, explains the increased synchronisation of arousals. Negative pathophysiological effects of WNS on energy conservation may therefore be compounded by maladaptive changes in behaviour of the bats, accelerating fat depletion and starvation.
Publisher: Brill
Date: 2016
DOI: 10.1163/1568539X-00003384
Abstract: Many animals change behaviour in response to pathogenic infections. White-nose syndrome (WNS) is a fungal skin disease causing rapid declines of North American bats. Infection with Pseudogymnoascus destructans causes hibernating bats to arouse from torpor too often, potentially causing starvation. Mechanisms underlying increased arousals are not understood but fungal invasion of the wings could trigger thirst to relieve fluid loss or grooming to relieve skin irritation. Alternatively, bats might exhibit ‘sickness behaviour’, a suite of responses to infection that save energy. We quantified behaviours of healthy and experimentally inoculated little brown bats ( Myotis lucifugus ) that could reflect active (i.e., drinking, grooming) or inactive (i.e., sickness behaviour) responses to infection. Infected bats groomed less and were less likely to visit their water dish compared to controls. These results are consistent with research suggesting that P. destructans causes sickness behaviour which could help bats compensate for energetic costs associated with infection.
Publisher: Elsevier BV
Date: 02-2014
Publisher: Springer Science and Business Media LLC
Date: 09-08-2005
DOI: 10.1007/S00360-005-0008-0
Abstract: Data on thermal energetics for vespertilionid bats are under-represented in the literature relative to their abundance, as are data for bats of very small body mass. Therefore, we studied torpor use and thermal energetics in one of the smallest (4 g) Australian vespertilionids, Vespadelus vulturnus. We used open-flow respirometry to quantify temporal patterns of torpor use, upper and lower critical temperatures (T (uc) and T (lc)) of the thermoneutral zone (TNZ), basal metabolic rate (BMR), resting metabolic rate (RMR), torpid metabolic rate (TMR), and wet thermal conductance (C (wet)) over a range of ambient temperatures (T (a)). We also measured body temperature (T (b)) during torpor and normothermia. Bats showed a high proclivity for torpor and typically aroused only for brief periods. The TNZ ranged from 27.6 degrees C to 33.3 degrees C. Within the TNZ T (b) was 33.3+/-0.4 degrees C and BMR was 1.02+/-0.29 ml O(2) g(-1) h(-1) (5.60+/-1.65 mW g(-1)) at a mean body mass of 4.0+/-0.69 g, which is 55 % of that predicted for a 4 g bat. Minimum TMR of torpid bats was 0.014+/-0.006 ml O(2) g(-1) h(-1) (0.079+/-0.032 mW g(-1)) at T (a)=4.6+/-0.4 degrees C and T (b)=7.5+/-1.9. T (lc) and C (wet) of normothermic bats were both lower than that predicted for a 4 g bat, which indicates that V. vulturnus is adapted to minimising heat loss at low T (a). Our findings support the hypothesis that vespertilionid bats have evolved energy-conserving physiological traits, such as low BMR and proclivity for torpor.
Publisher: Wiley
Date: 05-2015
DOI: 10.1890/140241
Publisher: Elsevier BV
Date: 10-2005
Publisher: Wiley
Date: 23-01-2014
DOI: 10.1111/JZO.12105
Publisher: Springer Science and Business Media LLC
Date: 07-10-2014
Publisher: Microbiology Society
Date: 09-2017
DOI: 10.1099/JGV.0.000898
Start Date: 06-2021
End Date: 05-2025
Amount: $543,024.00
Funder: Australian Research Council
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