Prevalence and Seasonality of the Amphibian Chytrid Fungus Batrachochytrium dendrobatidis Along Widely Separated Longitudes Across the United States

Host-pathogen specificity can arise from certain selective environments mediated by both the host and pathogen. Therefore, understanding the degree to which host species identity is correlated with pathogen genotype can help reveal historical host-pathogen dynamics. One animal disease of particular concern is chytridiomycosis, typically caused by the global panzootic lineage of the amphibian chytrid fungus ( Batrachochytrium dendrobatidis , Bd), termed the Bd-GPL. This pathogen lineage has caused devastating declines in amphibian communities around the world. However, the origin of Bd-GPL and the fine-scale transmission dynamics of this lineage have remained a mystery. This is especially the case in North America where Bd-GPL is widespread, but disease outbreaks occur sporadically. Herein, we use Bd genetic data collected throughout the United States from amphibian skin swab and cultured isolate samples to investigate Bd genetic patterns. We highlight two case studies in Pennsylvania and Nevada where Bd-GPL genotypes are strongly correlated with host species identity. Specifically, in some localities bullfrogs ( Rana catesbeiana ) are infected with Bd-GPL lineages that are distinct from those infecting other sympatric amphibian species. Overall, we reveal a previously unknown association of Bd genotype with host species and identify the eastern United States as a Bd diversity hotspot and potential ancestral population for Bd-GPL.

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Is overwintering mortality driving enigmatic declines? Evaluating the impacts of trematodes and the amphibian chytrid fungus on an anuran from hatching through overwintering

PLoS ONE ◽

10.1371/journal.pone.0262561 ◽

2022 ◽

Vol 17 (1) ◽

pp. e0262561

Author(s):

Olivia Wetsch ◽

Miranda Strasburg ◽

Jessica McQuigg ◽

Michelle D. Boone

Keyword(s):

Batrachochytrium Dendrobatidis ◽

Species Conservation ◽

Emerging Infectious Diseases ◽

The Novel ◽

Chytrid Fungus ◽

Growth And Survival ◽

Critical Life Events ◽

Overwintering Mortality ◽

Amphibian Chytrid Fungus

Emerging infectious diseases are increasing globally and are an additional challenge to species dealing with native parasites and pathogens. Therefore, understanding the combined effects of infectious agents on hosts is important for species’ conservation and population management. Amphibians are hosts to many parasites and pathogens, including endemic trematode flatworms (e.g., Echinostoma spp.) and the novel pathogenic amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Our study examined how exposure to trematodes during larval development influenced the consequences of Bd pathogen exposure through critical life events. We found that prior exposure to trematode parasites negatively impacted metamorphosis but did not influence the effect of Bd infection on terrestrial growth and survival. Bd infection alone, however, resulted in significant mortality during overwintering—an annual occurrence for most temperate amphibians. The results of our study indicated overwintering mortality from Bd could provide an explanation for enigmatic declines and highlights the importance of examining the long-term consequences of novel parasite exposure.

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Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in threatened corroboree frog populations in the Australian Alps

Diseases of Aquatic Organisms ◽

10.3354/dao02118 ◽

2009 ◽

Vol 92 (3) ◽

pp. 209-216 ◽

Cited By ~ 31

Author(s):

DA Hunter ◽

R Speare ◽

G Marantelli ◽

D Mendez ◽

R Pietsch ◽

...

Keyword(s):

Batrachochytrium Dendrobatidis ◽

Chytrid Fungus ◽

Australian Alps ◽

Amphibian Chytrid Fungus

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Non-detection of mycoviruses in amphibian chytrid fungus (Batrachochytrium dendrobatidis) from Australia

Fungal Biology ◽

10.1016/j.funbio.2021.10.004 ◽

2021 ◽

Author(s):

Rebecca J. Webb ◽

Alexandra A. Roberts ◽

Stephen Wylie ◽

Tiffany Kosch ◽

Luís Felipe Toledo ◽

...

Keyword(s):

Batrachochytrium Dendrobatidis ◽

Chytrid Fungus ◽

Amphibian Chytrid Fungus

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Sensitivity of histology for the detection of the amphibian chytrid fungus Batrachochytrium dendrobatidis

Journal of Veterinary Diagnostic Investigation ◽

10.1177/1040638718816116 ◽

2019 ◽

Vol 31 (2) ◽

pp. 246-249 ◽

Cited By ~ 1

Author(s):

Claudio Borteiro ◽

Francisco Kolenc ◽

José Manuel Verdes ◽

Claudio Martínez Debat ◽

Martín Ubilla

Keyword(s):

Skin Disease ◽

Batrachochytrium Dendrobatidis ◽

Pathogenic Fungus ◽

Chytrid Fungus ◽

Clinically Normal ◽

Frog Species ◽

Amphibian Chytrid Fungus

Histology is often underappreciated for the detection of the amphibian pathogenic fungus Batrachochytrium dendrobatidis, the cause of the potentially lethal skin disease chytridiomycosis. We evaluated the sensitivity of histology to detect chytrids in 20 wild specimens of 2 frog species from Uruguay that were clinically normal, but confirmed by PCR to be infected by B. dendrobatidis. We detected maturing and sporulated sporangia in 15 of 20 (75%) frogs, which is more sensitive than previously reported for histology. The effort needed to identify chytrids in histologic skin sections of Physalaemus henselii and Pleurodema bibroni required examination of 3.2 and 8.7 mm of skin sections for each frog species, respectively.

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