Pathogenesis of Chytridiomycosis, a Cause of Catastrophic Amphibian Declines

@article{Voyles2009PathogenesisOC,
  title={Pathogenesis of Chytridiomycosis, a Cause of Catastrophic Amphibian Declines},
  author={Jamie Voyles and Sam Young and Lee R. Berger and Craig R. Campbell and Wyatt F. Voyles and Anuwat Dinudom and David Cook and Rebecca J. Webb and Ross A. Alford and Lee F. Skerratt and Richard Speare},
  journal={Science},
  year={2009},
  volume={326},
  pages={582 - 585}
}
Croaking Frogs The global amphibian decline has been attributed, among other causes, to an amphibian skin disease chytridiomycosis caused by the fungus Batrachochytrium dendrobatidis. However, how this pathogen causes mortality has been unclear. Voyles et al. (p. 582) show that this superficial skin infection may lead to cardiac failure owing to changes caused by lowered ion transport through the skin and consequent electrolyte reduction in the blood. A fungal disease that is associated with… 

Emerging amphibian diseases in Queensland and host immune response to disease

It is suggested that B. dendrobatidis kills amphibians by disrupting normal epidermal functioning, leading to osmotic imbalance through loss of electrolytes, which is fundamental to understanding the host– pathogen relationship and thus the population declines attributed to B.

Does Chytridiomycosis Disrupt Amphibian Skin Function?

Evidence of inhibited rehydration in individuals exhibiting clinical signs of chytridiomycosis is provided, however, aclinical chy TRD does not severely affect amphibian skin function, and frogs that survive infection by Bd, even if they remain infected, may suffer no significant impairment in their physiological responses.

Pathophysiology in Mountain Yellow-Legged Frogs (Rana muscosa) during a Chytridiomycosis Outbreak

It is found that pathogen load is associated with disruptions in fluid and electrolyte balance, yet is not associated with fluctuations acid-base balance, which enhances knowledge of the pathophysiology of this disease and indicates that disease development is consistent across multiple species and in both laboratory and natural conditions.

Epidemiology of chytridiomycosis in rainforest stream tadpoles

The relationships between infection intensity, prevalence, tooth loss and body condition indicate that these tadpoles have a measure of tolerance or increased resistance, which may be a result of strong selection pressure exerted by chytridiomycosis, which is critical to properly understand and mitigate species declines and prevent extinction.

Enzootic and epizootic dynamics of the chytrid fungal pathogen of amphibians

Results suggest that host persistence versus extinction does not require differences in host susceptibility, pathogen virulence, or environmental conditions, and may be just epidemic and endemic population dynamics of the same host–pathogen system.

Immunological Aspects of Chytridiomycosis

An integrated synthesis of amphibian post-metamorphic immunological responses and the corresponding outcomes of infection with Batrachochytrium dendrobatidis is presented, focusing on recent developments within the field and highlighting future directions.

A pathogenic skin fungus and sloughing exacerbate cutaneous water loss in amphibians

Examining how skin sloughing, body size and Bd infection interact to influence water loss rates in five Australian frog species found that dehydration stress may be a significant factor contributing to the morbidity of severely Bd infected anurans, a symptom that is then exacerbated by an increased rate ofSloughing.

Do Frogs Infected with Batrachochytrium dendrobatidis Avoid Water While Sloughing?

This study provides insight into the behavioral effects of chytridiomycosis, demonstrating that Bd infection can induce behaviors that might alter disease progression and could contribute to intra- and interspecific differences in pathophysiology.

Population and disease dynamics of the amphibian chytrid fungus in the stream-associated frog Litoria rheocola

There was a significant interaction between the effects of season and site type on the prevalence of Bd in tadpoles, and infection persisted throughout summer and winter in populations at high elevations.

Host Stress Response Is Important for the Pathogenesis of the Deadly Amphibian Disease, Chytridiomycosis, in Litoria caerulea

Elevated baseline corticosterone is associated with chytridiomycosis and correlates with some of the deleterious effects observed during disease development, which is suggested to be a biochemical connection between these disparate effects.
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Experimental data support the conclusion that cutaneous chytridiomycosis is a fatal disease of anurans, and it is hypothesize that it is the proximate cause of these recent amphibian declines.

Distribution of Batrachochytrium dendrobatidis and pathology in the skin of green tree frogs Litoria caerulea with severe chytridiomycosis.

The number of sporangia was highly variable and this appeared to be related to the stage in the cycle of sloughing, and other pathological changes such as hyperkeratosis and congestion occurred much more frequently on ventral surfaces.

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