White Nose SyndromeA Caver’s Perspective

Hazel A. Barton, Ph.D.

Ashland Endowed Professor of Integrative ScienceAssociate Professor of Biological Sciences

Northern Kentucky University

WNS: What we know• White Nose Syndrome is manifested by a white,

powdery-like substance on the muzzle of infected bats

Blehert et al., (2009) Science 323:227

WNS: What we knowBats with WNS have much shorter torpor bouts

– This leads to a loss of reserves– Death comes from starvation or trying to find food during cold

weather

WNS: What we know

• Using phylogenetic analysis, the fungus (Geomyces destructans) is a newly identified member of the Geomyces.

Blehert et al., (2009) Science 323:227

Mammoth

Asian Elephant

African Elephant

Mastodon

Rhinoceros

Hippopotamus

Dogs and Humans

Blehert et al., (2009) Science 323:227

• Geomyces sp. have been described in a number of cave habitats, including:– Guano, isopod clasts, earthworms casts, cave

air, aragonite deposits, speleothems, sediments (caves do not contain soils)

– Tourist areas• Temperature range currently appears to be 10.2

– 12.0 ˚C• Not found as component bat fauna (France)• Geomyces spread by birds (Antarctica study)

Geomyces: What we know

Geomyces sp.: What we know

• Is structurally different from previously known Geomyces sp.

Blehert et al., (2009) Science 323:227

WNS: What we don’t know

• Is this fungus:– A new variant (a genetic change has led to

the emergence of a new strain/species)– A xenobiotic species (an invasive species that

has been introduced)

• Is this fungus:– A true pathogen (disease in healthy bats)– An opportunistic pathogen (takes advantage

of an immune suppressed bat)– Can be determined by Koch’s Postulates

WNS: If it is a true pathogen

• What is the multiplicity of infection (MOI)– What is the minimum number of spores

required for disease?– How many spores are found in cave air?– How many spores can be picked during

a caving trip?

WNS: If it is an opportunistic pathogen

• Underlying factors may be important:– Loss of chitinase activity– Loss of insect populations (WNV)– Use of different pesticides (WNV)– Climate change– Bat AIDS– Change in cave microbial ecosystems

WNS: If it is a frank pathogen• Control measures need to be evaluated

80+ agents

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Spore-only assaysUsing G. pannorum, G, desructans, Aspergillus, Penicillium

Three assays:• Disk diffusion – susceptibility

• Issues related to media• Role of geochemistry

• Total colony forming units (from 5 x 105 spores)• Germination assay

Testing

Decontamination Issues

Cave relevant materials

Plate

Agent C

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Control Agent C

Geomyces pannorum

Large Scale Treatments

• What about if we decontaminate caves?

Entrance Zone

The Depths

Heterotrophic InteractionsCompetitive exclusionBacterial dominance

Geochemically driven AutotrophyMutualistic Interactions

Archaeal dominance

Role of Fungi

Role of Fungi

Cave Microbiology: Fungi

• Natural members of cave microflora

• Appear highly diverse

• Break down rock (sugaring):

• Mechanically

• Chemically

• Play a role in nutrient acquisition

• Impacted by geochemistry

• Well adapted to oligotrophy

Barriers to Colonization

XenobioticOrganism

Chemical

Geochemicalconditions

Oligotrophy

Biological

Antifungal agentsbacterialfungal

Nutrient sequestrationResource competition

Summary

• Still investigating origins of G. destructans

• Still need to confirm whether this is a true pathogen

• Good idea on methods of decontamination

• Some ideas about in situ treatments

• In situ treatments need to be specific

Positive Effects of Cave Microbiology

• Novel organisms

• Novel antibiotics

• Novel polymers

• Novel bioremediation strategies

• CO2 sequestration

• Planetary protection strategies

• Unique geochemical interactions

Acknowledgements

Staff at Diamond CavernsStaff at Carlsbad Caverns NPStaff at Mammoth Cave NP

Staff at Wind Cave NP

Funding

Barton LabBrandon Heineke, Alexis Henry, Elizabeth Shelly and Tim Williams

On Rope 1Inner Mountain Outfitters

Sterling Ropes, Bluewater,PMI