Energetic benefits of enhanced summer roosting habitat for little brown bats (Myotis lucifugus) recovering from white-nose syndrome

Habitat modification can improve outcomes for imperilled wildlife. Insectivorous bats in North America face a range of conservation threats, including habitat loss and white-nose syndrome (WNS). Even healthy bats face energetic constraints during spring, but enhancement of roosting habitat could reduce energetic costs, increase survival and enhance recovery from WNS. We tested the potential of artificial heating of bat roosts as a management tool for threatened bat populations. We predicted that: (i) after hibernation, captive bats would be more likely to select a roost maintained at a temperature near their thermoneutral zone; (ii) bats recovering from WNS at the end of hibernation would show a stronger preference for heated roosts compared with healthy bats; and (iii) heated roosts would result in biologically significant energy savings. We housed two groups of bats (WNS-positive and control) in separate flight cages following hibernation. Over 7.5 weeks, we quantified the presence of individuals in heated vs. unheated bat houses within each cage. We then used a series of bioenergetic models to quantify thermoregulatory costs in each type of roost under a number of scenarios. Bats preferentially selected heated bat houses, but WNS-affected bats were much more likely to use the heated bat house compared with control animals. Our model predicted energy savings of up to 81.2% for bats in artificially heated roosts if roost temperature was allowed to cool at night to facilitate short bouts of torpor. Our results are consistent with research highlighting the importance of roost microclimate and suggest that protection and enhancement of high-quality, natural roosting environments should be a priority response to a range of threats, including WNS. Our findings also suggest the potential of artificially heated bat houses to help populations recover from WNS, but more work is needed before these might be implemented on a large scale.This work was supported by scholarships from the Natural Sciences and Engineering Research Council (NSERC, Canada) and University of Winnipeg Graduate Studies to A.W. and grants from the US Fish and Wildlife Service, Bat Conservation International and NSERC to C.K.R.W.https://academic.oup.com/conphys/article/4/1/cov070/295131

Using Behaviour to Understand Conservation and Management Strategies for Threatened Little Brown Bats (Myotis lucifugus)

A thesis submitted to the Faculty of Graduate Studies in partial fulfillment of the requirements for the Master of Science degree, Department of Biology. Master of Science in Bioscience, Technology, and Public Policy Program, University of Winnipeg.Captive assurance populations can help preserve populations in the face of rapid declines that cannot be mitigated in the wild. Individual behavioural tendencies or personality may affect how easily different individuals acclimate to captivity and ultimately influence the success of captive assurance efforts. Temperate bat species face a range of conservation threats including habitat loss and degradation, mortality from wind energy facilities, and white-nose syndrome (WNS), a fungal disease causing the most rapid declines of mammals ever observed. I tested the hypothesis that behavioural tendencies associated with animal personality and the shy-bold continuum affect feeding behaviour in healthy and WNS-affected captive little brown bats (Myotis lucifugus), one of the species most affected by WNS. I predicted that, in comparison to shy individuals, bold, active bats would spend more time feeding, feed more frequently, arrive earlier to the food dish each night, and gain more mass in captivity than shy individuals. Bats were captured from the wild in spring and held in the laboratory in one of two flight cages, isolating healthy and WNS-affected individuals. I quantified behavioural tendencies using a hole-board test and recorded feeding behaviour. Every two days during the feeding experiment, I recorded body mass to quantify pre-hibernation mass accumulation. I found that more active WNS-affected bats fed more frequently and that grooming in the hole-board test (which may reflect anxiety) was correlated with body mass at capture (i.e., at the end of the preceding hibernation season). I also found that individuals from both healthy and WNS-affected groups arrived at the feeding dish in approximately the same order each night, which could reflect a dominance hierarchy. However, I found no evidence that order of arrival at the food dish affected feeding or mass accumulation. My results suggest that behavioural tendencies during the active season may impact captive maintenance of bats for conservation, particularly those affected by disease. More work is required to understand the role of dominance interactions on the potential success of captive assurance populations.This research was supported by the Natural Sciences and Engineering Research Council Canada Graduate Scholarship and a University of Winnipeg Graduate Studies Scholarship. Grants were also provided to CKRW from the U.S. Fish and Wildlife Service, Canada Foundation for Innovation, and Bat Conservation International.Master of Science in Bioscience, Technology, and Public Polic

An Evaluation of Studies on the Potential Threats Contributing to the Decline of Eastern Migratory North American Monarch Butterflies (Danaus plexippus)

The migratory monarch butterflies (Danaus plexippus) of eastern North America have undergone large-scale declines, which may be attributable to a variety of underlying causes. The uncertainty about the primary cause of declines and whether individual threats are likely to increase in the future presents challenges for developing effective conservation management and policy initiatives that aim to improve population viability. This paper identifies five potential threats and classifies these threats according to the types of studies (observational, experimental, simulation/models) and their current impact and anticipated risk. Broadly, the threats can be classified into five categories: (1) change in suitable abiotic environmental conditions; (2) deforestation in the overwintering range; (3) exposure to contaminants including the bacteria Bacillus thuringiensis, herbicides, and insecticides; (4) loss of breeding habitat; and (5) predation, parasitism, and species-specific pathogens. The vast distribution of the monarch butterfly makes it likely that population declines are attributed to a suite of interacting factors that vary spatially and temporally in their contribution. Nonetheless, the published papers we reviewed suggest the decline in suitable environmental conditions in addition to overwintering (i.e., deforestation) and breeding habitat loss are the most likely threats to continue to affect the population viability of monarch butterflies

Improved eradication of Clostridium difficile spores from toilets of hospitalized patients using an accelerated hydrogen peroxide as the cleaning agent

<p>Abstract</p> <p>Background</p> <p><it>C. difficle </it>spores in the environment of patients with <it>C. difficile </it>associated disease (CDAD) are difficult to eliminate. Bleach (5000 ppm) has been advocated as an effective disinfectant for the environmental surfaces of patients with CDAD. Few alternatives to bleach for non-outbreak conditions have been evaluated in controlled healthcare studies.</p> <p>Methods</p> <p>This study was a prospective clinical comparison during non-outbreak conditions of the efficacy of an accelerated hydrogen peroxide cleaner (0.5% AHP) to the currently used stabilized hydrogen peroxide cleaner (0.05% SHP at manufacturer recommended use-dilution) with respect to spore removal from toilets in a tertiary care facility. The toilets used by patients who had diarrhea with and without <it>C. difficile </it>associated disease (CDAD) were cultured for <it>C. difficile </it>and were monitored using an ultraviolet mark (UVM) to assess cleaning compliance on a daily basis 5 days per week. A total of 243 patients and 714 samples were analysed. The culture results were included in the analysis only if the UVM audit from the same day confirmed that the toilet had been cleaned.</p> <p>Results</p> <p>Our data demonstrated that the efficacy of spore killing is formulation specific and cannot be generalized. The Oxivir_TB^®AHP formulation resulted in statistically significantly (p = 0.0023) lower levels of toxigenic <it>C. difficile </it>spores in toilets of patients with CDAD compared to the SHP formulation that was routinely being used (28% vs 45% culture positive). The background level of toxigenic <it>C. difficile </it>spores was 10% in toilets of patients with diarrhea not due to CDAD. The UVM audit indicated that despite the enhanced twice-daily cleaning protocol for CDAD patients cleaning was not achieved on approximately 30 - 40% of the days tested.</p> <p>Conclusion</p> <p>Our data indicate that the AHP formulation evaluated that has some sporicidal activity was significantly better than the currently used SHP formulation. This AHP formulation provides a one-step process that significantly lowers the <it>C. difficile </it>spore level in toilets during non-outbreak conditions without the workplace safety concerns associated with 5000 ppm bleach.</p

Aptamer-based multiplexed proteomic technology for biomarker discovery

Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine

Conspecific disturbance contributes to altered hibernation patterns in bats with white-nose syndrome

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 individuals 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 disturban

Behaviour of hibernating little brown bats experimentally inoculated with the pathogen that causes white-nose syndrome

Pathogens can affect host behaviour in ways that influence disease transmission as well as survival and fitness for both host and pathogen. Hibernating bats with white-nose syndrome (WNS) show a number of unusual behaviours including increased frequency of arousal from torpor, altered roosting behaviour and premature emergence. However, mechanisms underlying these patterns are not understood, and the behaviour of bats with WNS has not been examined systematically. Three hypotheses could explain increased arousal frequency. Bats may arouse to (1) groom in response to skin infection, (2) drink to offset dehydration or (3) increase activity, possibly in an attempt to access resources, avoid a source of infection or limit the risk of infecting relatives. We tested these hypotheses with captive little brown bats, Myotis lucifugus, inoculated with Pseudogymnoascus destructans, the fungus that causes WNS. In contrast to predictions of all three hypotheses, bats inoculated with the fungus tended to be less active than controls during arousals from torpor and did not increase grooming or visits to the water source in their enclosures. However, bats showed a dramatic reduction in clustering behaviour as infection progressed. Reduced activity and clustering could represent adaptive, maladaptive or pathological responses. Reduced activity could be an energy-saving mechanism or a pathological consequence of infection while reduced clustering could have beneficial or detrimental consequences for transmission, energetics, water balance and survival. Our results highlight the need for studies of host behaviour to understand dynamics of wildlife infectious diseases

The other white‐nose syndrome transcriptome: Tolerant and susceptible hosts respond differently to the pathogen Pseudogymnoascus destructans

Mitigation of emerging infectious diseases that threaten global biodiversity requires an understanding of critical host and pathogen responses to infection. For multihost pathogens where pathogen virulence or host susceptibility is variable, host–pathogen interactions in tolerant species may identify potential avenues for adaptive evolution in recently exposed, susceptible hosts. For example, the fungus Pseudogymnoascus destructans causes white‐nose syndrome (WNS ) in hibernating bats and is responsible for catastrophic declines in some species in North America, where it was recently introduced. Bats in Europe and Asia, where the pathogen is endemic, are only mildly affected. Different environmental conditions among Nearctic and Palearctic hibernacula have been proposed as an explanation for variable disease outcomes, but this hypothesis has not been experimentally tested. We report the first controlled, experimental investigation of response to P. destructans in a tolerant, European species of bat (the greater mouse‐eared bat, Myotis myotis ). We compared body condition, disease outcomes and gene expression in control (sham‐exposed) and exposed M. myotis that hibernated under controlled environmental conditions following treatment. Tolerant M. myotis experienced extremely limited fungal growth and did not exhibit symptoms of WNS . However, we detected no differential expression of genes associated with immune response in exposed bats, indicating that immune response does not drive tolerance of P. destructans in late hibernation. Variable responses to P. destructans among bat species cannot be attributed solely to environmental or ecological factors. Instead, our results implicate coevolution with the pathogen, and highlight the dynamic nature of the “white‐nose syndrome transcriptome.” Interspecific variation in response to exposure by the host (and possibly pathogen) emphasizes the importance of context in studies of the bat‐WNS system, and robust characterization of genetic responses to exposure in various ho