scholarly journals Amphibian Pathogen Batrachochytrium dendrobatidis Is Inhibited by the Cutaneous Bacteria of Amphibian Species

EcoHealth ◽  
2006 ◽  
Vol 3 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Reid N. Harris ◽  
Timothy Y. James ◽  
Antje Lauer ◽  
Mary Alice Simon ◽  
Amit Patel
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Amphibian Species ◽  
Amphibian Pathogen

scholarly journals Partitioning the net effect of host diversity on an emerging amphibian pathogen

2014 ◽  
Vol 281 (1795) ◽  
pp. 20141796 ◽  
Author(s):  
C. Guilherme Becker ◽  
David Rodriguez ◽  
L. Felipe Toledo ◽  
Ana V. Longo ◽  
Carolina Lambertini ◽  
...  
Keyword(s):  
Habitat Use ◽  
Life Histories ◽  
Batrachochytrium Dendrobatidis ◽  
Dilution Effect ◽  
Disease Dynamics ◽  
Amphibian Species ◽  
Host Interactions ◽  
Host Diversity ◽  
Underlying Causes ◽  
Amphibian Pathogen

The ‘dilution effect’ (DE) hypothesis predicts that diverse host communities will show reduced disease. The underlying causes of pathogen dilution are complex, because they involve non-additive (driven by host interactions and differential habitat use) and additive (controlled by host species composition) mechanisms. Here, we used measures of complementarity and selection traditionally employed in the field of biodiversity–ecosystem function (BEF) to quantify the net effect of host diversity on disease dynamics of the amphibian-killing fungus Batrachochytrium dendrobatidis ( Bd ). Complementarity occurs when average infection load in diverse host assemblages departs from that of each component species in uniform populations. Selection measures the disproportionate impact of a particular species in diverse assemblages compared with its performance in uniform populations, and therefore has strong additive and non-additive properties. We experimentally infected tropical amphibian species of varying life histories, in single- and multi-host treatments, and measured individual Bd infection loads. Host diversity reduced Bd infection in amphibians through a mechanism analogous to complementarity ( sensu BEF), potentially by reducing shared habitat use and transmission among hosts. Additionally, the selection component indicated that one particular terrestrial species showed reduced infection loads in diverse assemblages at the expense of neighbouring aquatic hosts becoming heavily infected. By partitioning components of diversity, our findings underscore the importance of additive and non-additive mechanisms underlying the DE.

scholarly journals Worrying News for Brazilian Caatinga: Prevalence of Batrachochytrium dendrobatidis in Amphibians

2019 ◽  
Vol 12 ◽  
pp. 194008291989262 ◽  
Author(s):  
Ronildo A. Benício ◽  
Tamilie Carvalho ◽  
Maria D. R. Barbosa ◽  
Janiella de M Costa ◽  
Felipe C. C. da Silva ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Batrachochytrium Dendrobatidis ◽  
New Records ◽  
Northeastern Brazil ◽  
Chytrid Fungus ◽  
Amphibian Species ◽  
Semiarid Climate ◽  
High Prevalence ◽  
Amphibian Pathogen

The chytrid fungus Batrachochytrium dendrobatidis (Bd) has been linked to the declines of more than 500 amphibian species globally. In Brazil, Bd has been identified in several regions but predominantly in the Atlantic Forest. Data on the occurrence of this amphibian pathogen in northeastern Brazil are scarce, specifically from the Caatinga ecoregion, where there is only one study that reports Bd in the region. This study is the first to show a high prevalence of Bd in Caatinga’s species and includes two new records of species infected by Bd: Rhinella granulosa and R. jimi. In addition, we discuss the possibility of amphibian with terrestrial habits serving as potential Bd reservoirs in semiarid climate regions.

Using occupancy models to understand the distribution of an amphibian pathogen, Batrachochytrium dendrobatidis

2010 ◽  
Vol 20 (1) ◽  
pp. 289-302 ◽  
Author(s):  
Michael J. Adams ◽  
Nathan D. Chelgren ◽  
David Reinitz ◽  
Rebecca A. Cole ◽  
Lara J. Rachowicz ◽  
...  
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Occupancy Models ◽  
Amphibian Pathogen

scholarly journals A dilution effect in the emerging amphibian pathogen Batrachochytrium dendrobatidis

2011 ◽  
Vol 108 (39) ◽  
pp. 16322-16326 ◽  
Author(s):  
C. L. Searle ◽  
L. M. Biga ◽  
J. W. Spatafora ◽  
A. R. Blaustein
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Dilution Effect ◽  
Amphibian Pathogen

scholarly journals Fungal infection, decline and persistence in the only obligate troglodytic Neotropical salamander

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9763
Author(s):  
Mizraim Olivares-Miranda ◽  
Vance T. Vredenburg ◽  
Julio C. García-Sánchez ◽  
Allison Q. Byrne ◽  
Erica B. Rosenblum ◽  
...  
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Infection Intensity ◽  
Sampling Technique ◽  
Sympatric Species ◽  
Amphibian Declines ◽  
Small Range ◽  
Museum Specimens ◽  
Amphibian Species ◽  
Extant Population ◽  
Epidemic Wave

The fungal pathogen Batrachochytrium dendrobatidis (Bd) is implicated in global mass die-offs and declines in amphibians. In Mesoamerica, the Bd epidemic wave hypothesis is supported by detection of Bd in historic museum specimens collected over the last century, yet the timing and impact of the early stages of the wave remain poorly understood. Chiropterotriton magnipes, the only obligate troglodytic Neotropical salamander, was abundant in its small range in the decade following its description in 1965, but subsequently disappeared from known localities and was not seen for 34 years. Its decline is roughly coincident with that of other populations of Neotropical salamanders associated with the invasion and spread of Bd. To determine the presence and infection intensity of Bd on C. magnipes and sympatric amphibian species (which are also Bd hosts), we used a noninvasive sampling technique and qPCR assay to detect Bd on museum specimens of C. magnipes collected from 1952 to 2012, and from extant populations of C. magnipes and sympatric species of amphibians. We also tested for the presence of the recently discovered Batrachochytrium salamandivorans (Bsal), another fungal chytridiomycete pathogen of salamanders, using a similar technique specific for Bsal. We did not detect Bd in populations of C. magnipes before 1969, while Bd was detected at low to moderate prevalence just prior to and during declines. This pattern is consistent with Bd-caused epizootics followed by host declines and extirpations described in other hosts. We did not detect Bsal in any extant population of C. magnipes. We obtained one of the earliest positive records of the fungus to date in Latin America, providing additional historical evidence consistent with the Bd epidemic wave hypothesis. Genotyping results show that at least one population is currently infected with the Global Panzootic Lineage of Bd, but our genotyping of the historical positive samples was unsuccessful. The lack of large samples from some years and the difficulty in genotyping historical Bd samples illustrate some of the difficulties inherent in assigning causality to historical amphibian declines. These data also provide an important historical baseline for actions to preserve the few known remaining populations of C. magnipes.

scholarly journals Establishement of a national monitoring program based on environmental DNA for amphibians and the chytrid fungus Batrachochytrium dendrobatidis     

2021 ◽  
Vol 4 ◽  
Author(s):  
Omneya Osman ◽  
Johan Andersson ◽  
Tomas Larsson ◽  
Mats Töpel ◽  
Alexander Eiler
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
National Level ◽  
Monitoring Program ◽  
12S Rrna ◽  
Rrna Gene ◽  
Chytrid Fungus ◽  
Rana Arvalis ◽  
Amphibian Species ◽  
National Monitoring ◽  
Wide Range

National monitoring programs provide the basis for evaluating the integrity of ecosystems, their responses to disturbances, and the success of actions taken to conserve or recover biodiversity. In this study, we successfully established a national program for the invasive chytrid fungus Batrachochytrium dendrobatidis (Bd) based on dual TaqMan assays. Amphibian diversity based on metabarcoding of the mitochondrial 12S rRNA gene was also performed. Assays were optimized for sensitive detection of target species from a wide range of amphibian ponds with variable potential of inhibitions for eDNA based detection. An amphibian mock community of 5 species was used to validate the metabarcoding approach while internal standards were used in the case of the dual TaqMan assays. First sampling of over 170 ponds in Norway resulted in Bd detection in 12 environmental samples and one swab sample taken over multiple years indicating the establishment of Bd in Norway. Five amphibian species Bufo bufo, Lissotriton vulgaris, Triturus cristatus, Rana arvalis and Rana temporaria as predicted from data in long-term citizen science reporting systems were widely detected in the collected eDNA samples. Our large scale-monitoring program indicates a low risk of a Bd outbreak and amphibian decline caused by chytridiomycosis but continued monitoring is recommended in the future. These findings indicate that eDNA is an effective method to detect invasive species, and to monitor endangered amphibian species. Still, several shortcomings (such as PCR inhibitors and sample volume) were identified that need to be addressed to improve eDNA-based monitoring at the national level.

scholarly journals Ancestral chytrid pathogen remains hypervirulent following its long coevolution with amphibian hosts

2019 ◽  
Vol 286 (1904) ◽  
pp. 20190833 ◽  
Author(s):  
Minjie Fu ◽  
Bruce Waldman
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Population Declines ◽  
Amphibian Species ◽  
South Korean ◽  
Global Pandemic ◽  
Litoria Caerulea ◽  
Experimental Treatments ◽  
Amphibian Chytrid Fungus ◽  
Genomic Recombination ◽  
Blank Solution

Many amphibian species around the world, except in Asia, suffer morbidity and mortality when infected by the emerging infectious pathogen Batrachochytrium dendrobatidis (Bd). A lineage of the amphibian chytrid fungus isolated from South Korean amphibians (BdAsia-1) is evolutionarily basal to recombinant global pandemic lineages (BdGPL) associated with worldwide amphibian population declines. In Asia, the Bd pathogen and its amphibian hosts have coevolved over 100 years or more. Thus, resilience of Asian amphibian populations to infection might result from attenuated virulence of endemic Bd lineages, evolved immunity to the pathogen or both. We compared susceptibilities of an Australasian amphibian, Litoria caerulea , known to lack resistance to BdGPL, with those of three Korean species, Bufo gargarizans , Bombina orientalis and Hyla japonica , after inoculation with BdAsia-1, BdGPL or a blank solution. Subjects became infected in all experimental treatments but Korean species rapidly cleared themselves of infection, regardless of Bd lineage. They survived with no apparent secondary effects. By contrast, L. caerulea , after infection by either BdAsia-1 or BdGPL, suffered deteriorating body condition and carried progressively higher Bd loads over time. Subsequently, most subjects died. Comparing their effects on L. caerulea , BdAsia-1 induced more rapid disease progression than BdGPL. The results suggest that genomic recombination with other lineages was not necessary for the ancestral Bd lineage to evolve hypervirulence over its long period of coevolution with amphibian hosts. The pathogen's virulence may have driven strong selection for immune responses in endemic Asian amphibian host species.

scholarly journals Tracking Batrachochytrium dendrobatidis Infection Across the Globe

EcoHealth ◽  
2020 ◽  
Vol 17 (3) ◽  
pp. 270-279
Author(s):  
Federico Castro Monzon ◽  
Mark-Oliver Rödel ◽  
Jonathan M. Jeschke
Keyword(s):  
Systematic Review ◽  
Host Species ◽  
Batrachochytrium Dendrobatidis ◽  
Atlantic Coast ◽  
Amphibian Species ◽  
Species Overlap ◽  
The Usa

AbstractInfection records of Batrachochytrium dendrobatidis (Bd), a pathogen that has devastated amphibian populations worldwide, have rapidly increased since the pathogen’s discovery. Dealing with so many records makes it difficult to (a) know where, when and in which species infections have been detected, (b) understand how widespread and pervasive Bd is and (c) prioritize study and management areas. We conducted a systematic review of papers and compiled a database with Bd infection records. Our dataset covers 71 amphibian families and 119 countries. The data revealed how widespread and adaptable Bd is, being able to infect over 50% of all tested amphibian species, with over 1000 confirmed host species and being present in 86 countries. The distribution of infected species is uneven among and within countries. Areas where the distributions of many infected species overlap are readily visible; these are regions where Bd likely develops well. Conversely, areas where the distributions of species that tested negative overlap, such as the Atlantic Coast in the USA, suggest the presence of Bd refuges. Finally, we report how the number of tested and infected species has changed through time, and provide a list of oldest detection records per country.

scholarly journals Phylogenetic investigation of skin sloughing rates in frogs: relationships with skin characteristics and disease-driven declines

2019 ◽  
Vol 286 (1896) ◽  
pp. 20182378 ◽  
Author(s):  
Michel E. B. Ohmer ◽  
Rebecca L. Cramp ◽  
Craig R. White ◽  
Peter S. Harlow ◽  
Michael S. McFadden ◽  
...  
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Phylogenetic Signal ◽  
Interspecific Variation ◽  
Phylogenetic Position ◽  
Turnover Rates ◽  
Amphibian Skin ◽  
Amphibian Species ◽  
Wide Range ◽  
Skin Morphology ◽  
And Function

Amphibian skin is highly variable in structure and function across anurans, and plays an important role in physiological homeostasis and immune defence. For example, skin sloughing has been shown to reduce pathogen loads on the skin, such as the lethal fungus Batrachochytrium dendrobatidis ( Bd ), but interspecific variation in sloughing frequency is largely unknown. Using phylogenetic linear mixed models, we assessed the relationship between skin turnover rate, skin morphology, ecological traits and overall evidence of Bd -driven declines. We examined skin sloughing rates in 21 frog species from three continents, as well as structural skin characteristics measured from preserved specimens. We found that sloughing rate varies significantly with phylogenetic group, but was not associated with evidence of Bd -driven declines, or other skin characteristics examined. This is the first comparison of sloughing rate across a wide range of amphibian species, and creates the first database of amphibian sloughing behaviour. Given the strong phylogenetic signal observed in sloughing rate, approximate sloughing rates of related species may be predicted based on phylogenetic position. While not related to available evidence of declines, understanding variation in sloughing rate may help explain differences in the severity of infection in genera with relatively slow skin turnover rates (e.g. Atelopus ).

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