scholarly journals Prevalence of the fungal pathogen Batrachochytrium dendrobatidis in amphibians of Costa Rica predated first-known epizootic

2018 ◽  
Author(s):  
Marina E. De León ◽  
Héctor Zumbado-Ulate ◽  
Adrián García-Rodríguez ◽  
Gilbert Alvarado ◽  
Hasan Sulaeman ◽  
...  
Keyword(s):  
Costa Rica ◽  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Emerging Infectious Diseases ◽  
Infection Prevalence ◽  
Pcr Assay ◽  
Local Data ◽  
Amphibian Species ◽  
Genetic Lineages ◽  
Quantitative Pcr Assay

AbstractEmerging infectious diseases are a growing threat to biodiversity worldwide. Outbreaks of the infectious disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), have caused the decline and extinction of numerous amphibian species. In Costa Rica, a major decline event occurred in 1987, more than two decades before this pathogen was discovered. The loss of many species in Costa Rica is assumed to be due to Bd-epizootics, but there are few studies that provide data from amphibians in the time leading up to the proposed epizootics. In this study, we provide new data on Bd infection rates of amphibians collected throughout Costa Rica, in the decades prior to the epizootics. We used a quantitative PCR assay to test for Bd infection in 1016 specimens collected throughout Costa Rica. We found Bd-infected hosts collected as early as 1964, and a infection prevalence average per decade of just 4%. The infection prevalence remained relatively low and geographically constrained until the 1980s when epizootics are hypothesized to have occurred. After that time, infection prevalence increased three-fold and Bd-infected hosts we collected throughout the entire country. Our results, suggest that Bd may either have invaded Costa Rica earlier than previously known, and spread more slowly than previously reported, or that an endemic lineage of the pathogen may exists. To help visualize areas where future studies should take place, we provide a Bd habitat suitability model trained with local data. Studies that provide information on genetic lineages of Bd are needed to determine whether an endemic lineage of Bd or the Global Panzootic Lineage (identified from mass die off sites globally) was present in Costa Rica and responsible for the epizootics that caused amphibian communities to collapse.

scholarly journals Antifungal Bacteria on Woodland Salamander Skin Exhibit High Taxonomic Diversity and Geographic Variability

2017 ◽  
Vol 83 (9) ◽  
Author(s):  
Carly R. Muletz-Wolz ◽  
Graziella V. DiRenzo ◽  
Stephanie A. Yarwood ◽  
Evan H. Campbell Grant ◽  
Robert C. Fleischer ◽  
...  
Keyword(s):  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Bacterial Species ◽  
Rrna Gene ◽  
Amphibian Skin ◽  
Amphibian Species ◽  
Protective Function ◽  
Content Type ◽  
Skin Bacteria ◽  
Salamander Species

ABSTRACT Diverse bacteria inhabit amphibian skin; some of those bacteria inhibit growth of the fungal pathogen Batrachochytrium dendrobatidis. Yet there has been no systematic survey of anti-B. dendrobatidis bacteria across localities, species, and elevations. This is important given geographic and taxonomic variations in amphibian susceptibility to B. dendrobatidis. Our collection sites were at locations within the Appalachian Mountains where previous sampling had indicated low B. dendrobatidis prevalence. We determined the numbers and identities of anti-B. dendrobatidis bacteria on 61 Plethodon salamanders (37 P. cinereus, 15 P. glutinosus, 9 P. cylindraceus) via culturing methods and 16S rRNA gene sequencing. We sampled co-occurring species at three localities and sampled P. cinereus along an elevational gradient (700 to 1,000 meters above sea level [masl]) at one locality. We identified 50 anti-B. dendrobatidis bacterial operational taxonomic units (OTUs) and found that the degree of B. dendrobatidis inhibition was not correlated with relatedness. Five anti-B. dendrobatidis bacterial strains occurred on multiple amphibian species at multiple localities, but none were shared among all species and localities. The prevalence of anti-B. dendrobatidis bacteria was higher at Shenandoah National Park (NP), VA, with 96% (25/26) of salamanders hosting at least one anti-B. dendrobatidis bacterial species compared to 50% (7/14) at Catoctin Mountain Park (MP), MD, and 38% (8/21) at Mt. Rogers National Recreation Area (NRA), VA. At the individual level, salamanders at Shenandoah NP had more anti-B. dendrobatidis bacteria per individual (μ = 3.3) than those at Catoctin MP (μ = 0.8) and at Mt. Rogers NRA (μ = 0.4). All salamanders tested negative for B. dendrobatidis. Anti-B. dendrobatidis bacterial species are diverse in central Appalachian Plethodon salamanders, and their distribution varied geographically. The antifungal bacterial species that we identified may play a protective role for these salamanders. IMPORTANCE Amphibians harbor skin bacteria that can kill an amphibian fungal pathogen, Batrachochytrium dendrobatidis. Some amphibians die from B. dendrobatidis infection, whereas others do not. The bacteria that can kill B. dendrobatidis, called anti-B. dendrobatidis bacteria, are thought to influence the B. dendrobatidis infection outcome for the amphibian. Yet how anti-B. dendrobatidis bacterial species vary among amphibian species and populations is unknown. We determined the distribution of anti-B. dendrobatidis bacterial species among three salamander species (n = 61) sampled at three localities. We identified 50 unique anti-B. dendrobatidis bacterial species and found that all of the tested salamanders were negative for B. dendrobatidis. Five anti-B. dendrobatidis bacterial species were commonly detected, suggesting a stable, functional association with these salamanders. The number of anti-B. dendrobatidis bacteria per individual varied among localities but not among co-occurring salamander species, demonstrating that environment is more influential than host factors in structuring the anti-B. dendrobatidis bacterial community. These anti-B. dendrobatidis bacteria may serve a protective function for their salamander hosts.

scholarly journals Amphibian species vary in their learned avoidance response to the deadly fungal pathogen Batrachochytrium dendrobatidis

2021 ◽  
Author(s):  
Taegan A. McMahon ◽  
Megan N. Hill ◽  
Garrett C. Lentz ◽  
Electra F. Scott ◽  
Nadia F. Tenouri ◽  
...  
Keyword(s):  
Avoidance Response ◽  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Amphibian Species

7. Batrachochytrium dendrobatidis

2015 ◽  
pp. 82-96
Author(s):  
Marta L. Wayne ◽  
Benjamin M. Bolker
Keyword(s):  
Natural History ◽  
Central America ◽  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Emerging Diseases ◽  
The Novel ◽  
Emerging Pathogen ◽  
Amphibian Species ◽  
History Of

Batrachochytrium dendrobatidis (Bd) is a fungal pathogen that infects many different amphibian species, driving some of them to extinction. ‘Batrachochytrium dendrobatidis’ considers the physiology and natural history of this emerging pathogen; its discovery in the late 1990s in Australia and Central America; and the concepts and strategies used to try to determine its origins. Has it arrived relatively recently in the communities it was destroying, or did it lie dormant in those communities for millennia before suddenly beginning to cause harm? The debate between the novel pathogen hypothesis and the endemic pathogen hypothesis, versions of which apply to most emerging diseases of wildlife, is ongoing.

scholarly journals Endemic Infection of Batrachochytrium dendrobatidis in Costa Rica: Implications for Amphibian Conservation at Regional and Species Level

Diversity ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 129 ◽  
Author(s):  
Héctor Zumbado-Ulate ◽  
Kiersten N. Nelson ◽  
Adrián García-Rodríguez ◽  
Gerardo Chaves ◽  
Erick Arias ◽  
...  
Keyword(s):  
Costa Rica ◽  
Batrachochytrium Dendrobatidis ◽  
Infection Intensity ◽  
Amphibian Conservation ◽  
Conservation Strategies ◽  
Amphibian Species ◽  
Current Impact ◽  
Taxonomic Groups ◽  
Species Descriptions ◽  
Effective Conservation

Batrachochytrium dendrobatidis (Bd) has been associated with the severe declines and extinctions of amphibians in Costa Rica that primarily occurred during the 1980s and 1990s. However, the current impact of Bd infection on amphibian species in Costa Rica is unknown. We aimed to update the list of amphibian species in Costa Rica and evaluate the prevalence and infection intensity of Bd infection across the country to aid in the development of effective conservation strategies for amphibians. We reviewed taxonomic lists and included new species descriptions and records for a total of 215 amphibian species in Costa Rica. We also sampled for Bd at nine localities from 2015–2018 and combined these data with additional Bd occurrence data from multiple studies conducted in amphibian communities across Costa Rica from 2005–2018. With this combined dataset, we found that Bd was common (overall infection rate of 23%) across regions and elevations, but infection intensity was below theoretical thresholds associated with mortality. Bd was also more prevalent in Caribbean lowlands and in terrestrial amphibians with an aquatic larval stage; meanwhile, infection load was the highest in direct-developing species (forest and stream-dwellers). Our findings can be used to prioritize regions and taxonomic groups for conservation strategies.

scholarly journals Distribution and Genetic Diversity of the Amphibian Chytrid in Japan

2021 ◽  
Vol 7 (7) ◽  
pp. 522
Author(s):  
Koichi Goka ◽  
Jun Yokoyama ◽  
Atsushi Tominaga
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Limited Area ◽  
Infection Prevalence ◽  
Chytrid Fungus ◽  
Amphibian Species ◽  
Okinawa Island ◽  
Dna Variation ◽  
The Status ◽  
Long Time ◽  
Pcr Method

While research on frog chytrid fungus Batrachochytrium dendrobatidis (Bd), an infectious disease that threatens amphibian diversity, continues to advance worldwide, little progress has been made in Japan since around 2010. The reason for this is, which we pointed out in 2009, that the origin of frog chytrid fungus may be in the East Asian region, including Japan based on the Bd ITS-DNA variation, and as few cases of mass mortality caused by this fungus have been observed in wild amphibian populations in Japan, the interest of the Japanese government and the general public in Bd has waned. However, we believe that organizing the data obtained so far in Japan and distributing the status of frog chytrid fungus in Japan to the world will provide useful insight for future risk management of this pathogen. We collected more than 5500 swab samples from wild amphibians throughout Japan from 2009 to 2010. Then, we investigated the infection status using the Nested-PCR method. We sequenced the obtained DNA samples and constructed a maximum-parsimony (MP) tree to clarify the phylogenetic diversity of Bd. We detected Bd infection in 11 (nine native and two alien) amphibian species in Japan and obtained 44 haplotypes of Bd ITS-DNA. The MP tree showed a high diversity of Bd strains in Japan, suggesting that some strains belong to Bd-GPL and Bd-Brazil. Except for local populations of the Japanese giant salamanders Andrias japonicus in Honshu Island and the sword tail newts Cynops ensicauda in Okinawa Island, the Bd infection prevalence in native amphibian species was very low. The alien bullfrog Aquarana catesbeiana had high Bd infection rates in all areas where they were sampled. No Bd infection was detected in other native amphibians in the areas where giant salamanders, sword tail newts, and bullfrogs were collected, suggesting that many native amphibians are resistant to Bd infection. The sword tail newt of Okinawa Island had both the highest infectious incidence and greatest number of haplotypes. The giant salamanders also showed relatively high infection prevalence, but the infected strains were limited to those specific to this species. These two Caudata species are endemic to a limited area of Japan, and it was thought that they may have been refugia for Bd, which had been distributed in Japan Islands for a long time.

scholarly journals Reservoir frogs: seasonality of Batrachochytrium dendrobatidis infection in robber frogs in Dominica and Montserrat

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7021 ◽  
Author(s):  
Michael A. Hudson ◽  
Richard A. Griffiths ◽  
Lloyd Martin ◽  
Calvin Fenton ◽  
Sarah-Louise Adams ◽  
...  
Keyword(s):  
Wildlife Conservation ◽  
Batrachochytrium Dendrobatidis ◽  
Seasonal Pattern ◽  
Emerging Infectious Diseases ◽  
Seasonal Patterns ◽  
Infection Prevalence ◽  
Reservoir Species ◽  
Reintroduction Success ◽  
Species Declines

Emerging infectious diseases are an increasingly important threat to wildlife conservation, with amphibian chytridiomycosis, caused by Batrachochytrium dendrobatidis, the disease most commonly associated with species declines and extinctions. However, some amphibians can be infected with B. dendrobatidis in the absence of disease and can act as reservoirs of the pathogen. We surveyed robber frogs (Eleutherodactylus spp.), potential B. dendrobatidis reservoir species, at three sites on Montserrat, 2011–2013, and on Dominica in 2014, to identify seasonal patterns in B. dendrobatidis infection prevalence and load (B. dendrobatidis genomic equivalents). On Montserrat there was significant seasonality in B. dendrobatidis prevalence and B. dendrobatidis load, both of which were correlated with temperature but not rainfall. B. dendrobatidis prevalence reached 35% in the cooler, drier months but was repeatedly undetectable during the warmer, wetter months. Also, B. dendrobatidis prevalence significantly decreased from 53.2% when the pathogen emerged on Montserrat in 2009 to a maximum 34.8% by 2011, after which it remained stable. On Dominica, where B. dendrobatidis emerged seven years prior to Montserrat, the same seasonal pattern was recorded but at lower prevalence, possibly indicating long-term decline. Understanding the dynamics of disease threats such as chytridiomycosis is key to planning conservation measures. For example, reintroductions of chytridiomycosis-threatened species could be timed to coincide with periods of low B. dendrobatidis infection risk, increasing potential for reintroduction success.

Locality, time and heterozygosity affect chytrid infection in yellow-bellied toads

2020 ◽  
Vol 142 ◽  
pp. 225-237
Author(s):  
P Oswald ◽  
A Rodríguez ◽  
J Bourke ◽  
N Wagner ◽  
N de Buhr ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Breeding Season ◽  
Batrachochytrium Dendrobatidis ◽  
Infection Intensity ◽  
Sampling Period ◽  
Infection Prevalence ◽  
Infection Status ◽  
Population Declines ◽  
Amphibian Species ◽  
High Genetic Diversity

The chytrid fungus Batrachochytrium dendrobatidis (Bd) infects numerous amphibian species worldwide and is suggested to drive population declines and extinction events. We report a study of Bd infection at the northernmost distribution of the European yellow-bellied toad Bombina variegata. A total of 577 individuals from ponds in 16 study sites were sampled for DNA and Bd throughout the breeding season. Microsatellite genotyping revealed 3 genetic clusters for the host B. variegata with an overall low genetic diversity. One of the clusters displayed a low microsatellite heterozygosity, a high inbreeding coefficient as well as high Bd infection prevalence and intensities. Multi-model estimates identified site, time of sampling, and heterozygosity to be important predictors of an individual’s Bd infection status, and identified a strong effect of site on individual Bd infection intensity. The study site effects are suggestive of localized infection peaks, and the increase of individual Bd infection probabilities towards the end of the sampling period suggests cumulative infection during the breeding season. This study highlights the need for regular monitoring of Bd infection variables at multiple localities and times to gain insights into Bd dynamics. Due to the detected relationship between individual Bd infection status and heterozygosity, conservation measures should focus on the maintenance of high genetic diversity and connectivity within and among amphibian populations.

Exciting new discovery for the chytrid mystery

2018 ◽  
Vol 182 (8) ◽  
pp. 212-213
Keyword(s):  
Infectious Disease ◽  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Emerging Infectious Disease ◽  
Amphibian Species ◽  
New Research ◽  
Shed Light ◽  
New Discovery

The emerging infectious disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis, is thought to affect over 500 amphibian species worldwide. But, as Georgina Mills explains, new research has now shed light on what could make some individuals more susceptible

scholarly journals The Effect of Aquatic and Terrestrial Environmental Factors on the Interaction Between Grand Teton Boreal Toads and a Lethal Fungal Pathogen

2008 ◽  
Vol 31 ◽  
pp. 125-131
Author(s):  
Peter Murphy ◽  
Sophie St-Hilaire ◽  
Charles Peterson
Keyword(s):  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Chytrid Fungus ◽  
Population Declines ◽  
Amphibian Skin ◽  
Amphibian Species ◽  
American Bullfrog ◽  
The North ◽  
S 100 ◽  
Boreal Toads

Batrachochytrium dendrobatidis (Bd), the chytrid fungus which infects keratinized amphibian skin and causes the lethal disease chytridiomycosis, has been linked to population declines and extinctions worldwide (Lips et al. 2006). Amphibians infected with Bd may suffer a variety of outcomes. Individuals of some species have been killed by :S 100 Bd zoospores, while other species, such as the North American bullfrog Rana catesbiana, are highly resistant (Daszak et al. 2004). Within an amphibian species, populations may also respond differently to Bd, with some declining et al. remaining stable (Kriger and Hero 2006). Divergent outcomes among species and populations with respect to Bd may arise from at least three factors, or their interaction.

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