skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Preparing for invasion: Assessing risk of infection by chytrid fungi in southeastern plethodontid salamanders
Abstract Understanding the responses of naïve communities to the invasion of multihost pathogens requires accurate estimates of susceptibility across taxa. In the Americas, the likely emergence of a second amphibian pathogenic fungus (Batrachochytrium salamandrivorans, Bsal) calls for new ways of prioritizing disease mitigation among species due to the high diversity of naïve hosts with priorB. dendrobatidis(Bd) infections. Here, we applied the concept of pathogenic potential to quantify the virulence of chytrid fungi on naïve amphibians and evaluate species for conservation efforts in the event of an outbreak. The benefit of this measure is that it combines and summarizes the variation in disease effects into a single numerical index, allowing for comparisons across species, populations or groups of individuals that may inherently exhibit differences in susceptibility. As a proof of concept, we obtained standardized responses of disease severity by performing experimental infections withBsalon five plethodontid salamanders from southeastern United States. Four out of five species carried natural infections ofBdat the start of the experiments. We showed thatBsalexhibited its highest value of pathogenic potential in a species that is already declining (Desmognathus auriculatus). We find that this index provides additional information beyond the standard measures of disease prevalence, intensity, and mortality, because it leveraged these disease parameters within each categorical group. Scientists and practitioners could use this measure to justify research, funding, trade, or conservation measures.  more » « less
Award ID(s):
1735038
PAR ID:
10382114
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Journal of Experimental Zoology Part A: Ecological and Integrative Physiology
Volume:
333
Issue:
10
ISSN:
2471-5638
Format(s):
Medium: X Size: p. 829-840
Size(s):
p. 829-840
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; (, Diversity and Distributions)
    Xuan Liu (Ed.)
    Aim: Amphibian populations are threatened globally by anthropogenic change and Batrachochytrium dendrobatidis (Bd), a fungal pathogen causing chytridiomycosis disease to varying degrees of severity. A closely related new fungal pathogen, Batrachochytrium salamandrivorans (Bsal), has recently left its supposed native range in Asia and decimated some salamander populations in Europe. Despite being noticed initially for causing chytridiomycosis-related population declines in salamanders, Bsal can also infect anurans and cause non-lethal chytridiomycosis or asymptomatic infections in salamanders. Bsal has not yet been detected in the United States, but given the United States has the highest salamander biodiversity on Earth, predictive assessments of salamander risk to Bsal infection will enable proactive allocation of research and conservation efforts into disease prevention and mitigation. Location: The United States, Europe and Asia. Methods: We first predicted the environmental suitability for the Bsal pathogen in the United States through an ecological niche model based on the pathogen's known native range in Asia, validated on the observed invasive range in Europe using bioclimatic, land cover, elevation, soil characteristics and human modification variables. Second, we predicted the susceptibility of salamander species to Bsal infection using a machine-learning model that correlated life history traits with published data on confirmed species infections. Finally, we mapped the geographic ranges of the subset of species that were predicted to be susceptible to Bsal infection. Results: In the United States, the overlap of environmental suitability and susceptible salamander species was greatest in the Pacific Northwest, near the Gulf of Mexico, and along the Atlantic coast, and in inland states east of the Plains region. Main Conclusions: The overlap of these metrics identify salamander populations that may be at risk of developing Bsal infection and suggests priorities for pre-emptive research and conservation measures to protect at-risk salamander species from an additional pathogenic threat. 
    more » « less
  2. ; ; ; ; ; ; ; ; (, Journal of Applied Ecology)
    Abstract Batrachochytrium dendrobatidis(Bd), an aquatic pathogenic fungus, is responsible for the decline of hundreds of amphibian species worldwide and negatively impacts biodiversity globally. Prophylactic exposure to the metabolites produced by Bd can provide protection for naïve tree frogs and reduce subsequent Bd infection intensity.Here, we used a response surface design crossing Bd metabolite prophylaxis concentration and exposure duration to determine how these factors modulate prophylactic protection against Bd in Pacific chorus frog (Pseudacris regilla) tadpoles (5 × 5 surface design) and metamorphs (3 × 3 surface design). We exposed individuals every weekday to one of five Bd metabolite concentrations or a water control for 1–5 weeks, after which all animals were challenged with live Bd to evaluate their susceptibility.Exposure to the Bd metabolite prophylaxis reduced Bd load and prevalence compared to the control for both the tadpoles and metamorphs. Increasing Bd metabolite prophylaxis concentration did not confer additional protection for either life stage, but increasing duration of exposure did benefit metamorphs by decreasing Bd prevalence but not Bd load.On average, control tadpoles and metamorphs had 66.2% and 99.4% higher Bd loads, respectively, than tadpoles and metamorphs exposed to any Bd metabolite prophylaxis.Additionally, Bd metabolite prophylaxis reduced Bd prevalence relative to controls in both tadpoles (20.5% vs. 56.3%, respectively) and metamorphs (21.9% vs. 87.5%, respectively).Synthesis and applications: The efficacy of short‐term exposures of relatively low concentrations of Bd metabolites at reducing Bd infections suggests that this approach has the potential to be scaled up to field use to aid in disease mitigation and conservation. Our results, combined with additional research on Bd metabolite prophylaxis for other amphibian species, suggest that this strategy may represent a broadly useful tool to protect at‐risk amphibian populations. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Frontiers in Amphibian and Reptile Science)
    Western palearctic salamander susceptibility to the skin disease caused by the amphibian chytrid fungusBatrachochytrium salamandrivorans(Bsal) was recognized in 2014, eliciting concerns for a potential novel wave of amphibian declines following theB. dendrobatidis(Bd) chytridiomycosis global pandemic. Although Bsal had not been detected in North America, initial experimental trials supported the heightened susceptibility of caudate amphibians to Bsal chytridiomycosis, recognizing the critical threat this pathogen poses to the North American salamander biodiversity hotspot. Here, we take stock of 10 years of research, collaboration, engagement, and outreach by the North American Bsal Task Force. We summarize main knowledge and conservation actions to both forestall and respond to Bsal invasion into North America. We address the questions: what have we learned; what are current challenges; and are we ready for a more effective reaction to Bsal’s eventual detection? We expect that the many contributions to preemptive planning accrued over the past decade will pay dividends in amphibian conservation effectiveness and can inform future responses to other novel wildlife diseases and extreme threats. 
    more » « less
  4. ; ; (, Global Amphibian and Reptile Disease Conference)
    The potential emergence of Batrachochytrium salamandrivorans (Bsal) in North America threatens salamander diversity and ecosystem functioning, thus an understanding of mechanisms influencing host survival during infection is key to predict future impacts. Previous studies indicate that temperature plays a role in regulating infection dynamics, in that access to a thermal gradient provides the means to prevent infections. Phenotypic flexibility is a likely mechanism, as temperature can enhance (or suppress) host functional capacity in both lunged and lungless salamanders. However, we know very little about how hosts are using thermal environments to achieve effective immune gene expression during Bsal infection. Through a series of experiments, we aim to 1) reveal if interspecific differences in disease susceptibility and functional responses are exacerbated by thermal environments, 2) determine if hosts can minimize the metabolic costs of infections by selecting optimal environments, and 3) project susceptibility risk across the landscape using information about species’ thermal preferences. We discuss our plans to evaluate immune gene expression, metabolic rates and thermoregulation relating to infection with Bsal and access to different thermal environments in plethodontid salamanders from Florida. Additionally, to develop models to predict infection susceptibility, we are seeking collaborations in compiling data on thermal preferences and thermal limits across plethodontid salamander species. 
    more » « less
  5. ; ; ; ; ; (, Frontiers in Veterinary Science)
    Emerging infectious diseases have been especially devastating to amphibians, the most endangered class of vertebrates. For amphibians, the greatest disease threat is chytridiomycosis, caused by one of two chytridiomycete fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans ( Bsal ). Research over the last two decades has shown that susceptibility to this disease varies greatly with respect to a suite of host and pathogen factors such as phylogeny, geography (including abiotic factors), host community composition, and historical exposure to pathogens; yet, despite a growing body of research, a comprehensive understanding of global chytridiomycosis incidence remains elusive. In a large collaborative effort, Bd -Maps was launched in 2007 to increase multidisciplinary investigations and understanding using compiled global Bd occurrence data ( Bsal was not discovered until 2013). As its database functions aged and became unsustainable, we sought to address critical needs utilizing new technologies to meet the challenges of aggregating data to facilitate research on both Bd and Bsal . Here, we introduce an advanced central online repository to archive, aggregate, and share Bd and Bsal data collected from around the world. The Amphibian Disease Portal ( https://amphibiandisease.org ) addresses several critical community needs while also helping to build basic biological knowledge of chytridiomycosis. This portal could be useful for other amphibian diseases and could also be replicated for uses with other wildlife diseases. We show how the Amphibian Disease Portal provides: (1) a new repository for the legacy Bd- Maps data; (2) a repository for sample-level data to archive datasets and host published data with permanent DOIs; (3) a flexible framework to adapt to advances in field, laboratory, and informatics technologies; and (4) a global aggregation of Bd and Bsal infection data to enable and accelerate research and conservation. The new framework for this project is built using biodiversity informatics best practices and metadata standards to ensure scientific reproducibility and linkages across other biological and biodiversity repositories. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email