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Morphological and molecular characterizations of psychrophilic fungus Geomyces destructans from New York bats with White Nose Syndrome (WNS).

Chaturvedi V, Springer DJ, Behr MJ, Ramani R, Li X, Peck MK, Ren P, Bopp DJ, Wood B, Samsonoff WA, Butchkoski CM, Hicks AC, Stone WB, Rudd RJ, Chaturvedi S - PLoS ONE (2010)

Bottom Line: The fungus has been recovered sparsely despite plentiful availability of afflicted animals.Further 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.

View Article: PubMed Central - PubMed

Affiliation: Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, New York, USA. vishnu@wadsworth.org

ABSTRACT

Background: Massive 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 findings: We 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/significance: Further 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.

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Microscopic and histopathological evidence of G. destructans in bats with WNS.(A) Direct lactophenol cotton blue mount prepared from skin scrape taken from the muzzle of a little brown bat from Graphite Mine on April 6, 2008 revealed fungal hyphae and curved conidia, bar 10 µm. (B) Control, [Bi] and infected muzzle tissue section [Bii] stained with PAS revealed epidermal colonization by fungal hyphae and spores; the sample was from a little brown bat from Williams Hotel Mine on March 27, 2008. Notably, a few neutrophils are present in the underlying dermis (arrows), bar 10 µm. Bacteria are also seen in this sample (C). SEM photomicrograph of muzzle sample from bat from Williams Hotel Mine showing characteristic curved conidia and septate hyphae spread over bat skin tissues. Note heavy fungal growth with profuse curved conidia covering the skin and hair shaft (Ci, muzzle, bar 100 µm; Cii, higher magnification of a portion of muzzle, bar 10 µm; Ciii & Cvi, higher magnifications, bar 10 µm).
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pone-0010783-g001: Microscopic and histopathological evidence of G. destructans in bats with WNS.(A) Direct lactophenol cotton blue mount prepared from skin scrape taken from the muzzle of a little brown bat from Graphite Mine on April 6, 2008 revealed fungal hyphae and curved conidia, bar 10 µm. (B) Control, [Bi] and infected muzzle tissue section [Bii] stained with PAS revealed epidermal colonization by fungal hyphae and spores; the sample was from a little brown bat from Williams Hotel Mine on March 27, 2008. Notably, a few neutrophils are present in the underlying dermis (arrows), bar 10 µm. Bacteria are also seen in this sample (C). SEM photomicrograph of muzzle sample from bat from Williams Hotel Mine showing characteristic curved conidia and septate hyphae spread over bat skin tissues. Note heavy fungal growth with profuse curved conidia covering the skin and hair shaft (Ci, muzzle, bar 100 µm; Cii, higher magnification of a portion of muzzle, bar 10 µm; Ciii & Cvi, higher magnifications, bar 10 µm).

Mentions: Skin scrapes were taken from the muzzles of four little brown bats from the Graphite Mine on April 4, 2008. Lactophenol cotton blue mounts of these specimens showed curved conidia characteristic of ascomycetes fungi (Fig. 1A). Sections of skin from muzzles of four humanely euthanized little brown bats collected from the Williams Hotel Mine on March 27, 2008, showed epidermal colonization with focal dermatitis including a few neutrophils in the underlying dermis and fungal hyphae and spores intermixed with bacteria near the surface (Fig. 1Bi, ii). Pathology and virology studies carried out in parallel did not reveal any known bacterial, viral, or parasitic pathogens (details not shown). The evidence for the presence of a mycelial fungus in affected areas of the infected bats was obtained when tissue samples from the Williams Hotel Mine were examined by SEM; this imaging method revealed abundant fungal growth on skin and hair shafts (Fig. 1Ci-iv). The above observations led us to focus on the recovery of the mold from bat tissues and environmental samples.


Morphological and molecular characterizations of psychrophilic fungus Geomyces destructans from New York bats with White Nose Syndrome (WNS).

Chaturvedi V, Springer DJ, Behr MJ, Ramani R, Li X, Peck MK, Ren P, Bopp DJ, Wood B, Samsonoff WA, Butchkoski CM, Hicks AC, Stone WB, Rudd RJ, Chaturvedi S - PLoS ONE (2010)

Microscopic and histopathological evidence of G. destructans in bats with WNS.(A) Direct lactophenol cotton blue mount prepared from skin scrape taken from the muzzle of a little brown bat from Graphite Mine on April 6, 2008 revealed fungal hyphae and curved conidia, bar 10 µm. (B) Control, [Bi] and infected muzzle tissue section [Bii] stained with PAS revealed epidermal colonization by fungal hyphae and spores; the sample was from a little brown bat from Williams Hotel Mine on March 27, 2008. Notably, a few neutrophils are present in the underlying dermis (arrows), bar 10 µm. Bacteria are also seen in this sample (C). SEM photomicrograph of muzzle sample from bat from Williams Hotel Mine showing characteristic curved conidia and septate hyphae spread over bat skin tissues. Note heavy fungal growth with profuse curved conidia covering the skin and hair shaft (Ci, muzzle, bar 100 µm; Cii, higher magnification of a portion of muzzle, bar 10 µm; Ciii & Cvi, higher magnifications, bar 10 µm).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2875398&req=5

pone-0010783-g001: Microscopic and histopathological evidence of G. destructans in bats with WNS.(A) Direct lactophenol cotton blue mount prepared from skin scrape taken from the muzzle of a little brown bat from Graphite Mine on April 6, 2008 revealed fungal hyphae and curved conidia, bar 10 µm. (B) Control, [Bi] and infected muzzle tissue section [Bii] stained with PAS revealed epidermal colonization by fungal hyphae and spores; the sample was from a little brown bat from Williams Hotel Mine on March 27, 2008. Notably, a few neutrophils are present in the underlying dermis (arrows), bar 10 µm. Bacteria are also seen in this sample (C). SEM photomicrograph of muzzle sample from bat from Williams Hotel Mine showing characteristic curved conidia and septate hyphae spread over bat skin tissues. Note heavy fungal growth with profuse curved conidia covering the skin and hair shaft (Ci, muzzle, bar 100 µm; Cii, higher magnification of a portion of muzzle, bar 10 µm; Ciii & Cvi, higher magnifications, bar 10 µm).
Mentions: Skin scrapes were taken from the muzzles of four little brown bats from the Graphite Mine on April 4, 2008. Lactophenol cotton blue mounts of these specimens showed curved conidia characteristic of ascomycetes fungi (Fig. 1A). Sections of skin from muzzles of four humanely euthanized little brown bats collected from the Williams Hotel Mine on March 27, 2008, showed epidermal colonization with focal dermatitis including a few neutrophils in the underlying dermis and fungal hyphae and spores intermixed with bacteria near the surface (Fig. 1Bi, ii). Pathology and virology studies carried out in parallel did not reveal any known bacterial, viral, or parasitic pathogens (details not shown). The evidence for the presence of a mycelial fungus in affected areas of the infected bats was obtained when tissue samples from the Williams Hotel Mine were examined by SEM; this imaging method revealed abundant fungal growth on skin and hair shafts (Fig. 1Ci-iv). The above observations led us to focus on the recovery of the mold from bat tissues and environmental samples.

Bottom Line: The fungus has been recovered sparsely despite plentiful availability of afflicted animals.Further 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.

View Article: PubMed Central - PubMed

Affiliation: Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, New York, USA. vishnu@wadsworth.org

ABSTRACT

Background: Massive 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 findings: We 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/significance: Further 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.

Show MeSH