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Our Studies

Evaluating the susceptibility and risk of amphibian species to Batrachochytrium salamandrivorans (Bsal) in North America.

Risk assessment illustrating the likelihood of Bsal invasion given environmental suitability, proximity to importation ports, and salamander species richness.
Risk assessment by Yap et al. (2015; left; Science 349:481-482) and Richgels et al. (2016; right; Royal Soc. Open Sci. 3:150616) illustrating the likelihood of Bsal invasion given environmental suitability, proximity to importation ports, and salamander species richness.

Risk models based on salamander species richness and environmental suitability of Bsal zoospores suggest likely regions of emergence are the southeastern and northwestern United States and southern Mexico. There is urgent need to estimate the susceptibility of salamander species in these regions to Bsal for more robust science-based risk assessments, which can provide guidance to natural resource agencies in developing disease intervention strategies.

Progress: As of September 2018, we have completed Bsal susceptibility trials on 30 amphibian species (24 salamander and six frog species from nine families); three of those species are from Mexico. Future efforts include testing 18 additional species (ten eastern USA, eight western USA) in collaboration with Washington State University. We also are collaborating with University of Georgia to test the susceptibility of salamander species from Costa Rica.

Collaborators: 

  • Priya Nanjappa
  • Reid Harris
  • Lori Williams
  • Pandy Upchurch
  • Doug Woodhams
  • Molly Bletz
  • Louise Rollins-Smith
  • Jonah Piovia-Scott
  • Sonia Hernandez
  • Henry Adams
  • Gabriella Parra Olea
  • Tim Herman
  • Jessi Krebs
  • Diane Barber 

Funding: 

  • BAND Foundation
  • Association of Fish and Wildlife Agencies
  • North Carolina Wildlife Resources Agencies
  • Tennessee Wildlife Resources Agency
  • US Fish and Wildlife Service
  • Liquid Spark

Susceptibility of North American newts to Batrachochytrium salamandrivorans among species, populations, and age classes.

A chart showing survival rates of salamanders infected with Bsal pathogen.
Survival of striped newts (Notophthalmus peristriatus, NOPE), black-spotted newts (N. meridionalis, NOME), and six populations of eastern newts (N. viridescens, NOVI) following exposure to Bsal at four zoospore doses. M. Gray and D. Miller, unpublished data.

Progress: The recently discovered fungal pathogen Batrachochytrium salamandrivorans (Bsal) has caused population declines of wild fire salamanders (Salamandra salamandra) in Europe, and preliminary controlled experiments suggest that Bsal is highly pathogenic to species in the family Salamandridae (i.e., newts). Our goal was to robustly estimate the susceptibility of four North American newt species (Notophthalmus viridescens, N. perstriatus, N. meridionalis, and Taricha granulosa) to Bsal infection and chytridiomycosis. For N. viridescens, we were able to test the susceptibility of six populations from four US states. Animals were exposed to one of four zoospore doses (5×103-6) at 15o C for 24 hours, and their condition and fate were monitored for at least six weeks.

In general, the greatest mortality, infection prevalence, and Bsal loads were in the following order: N. meridionalis (greatest), N. perstriatus, Taricha granulosa, and N. viridescens (least). In addition, susceptibility differed among N. viridescens populations, with the greatest occurrence of Bsal chytridiomycosis occurring in the Michigan population and least in the Blue Ridge physiographic region, Tennessee (100 percent vs. 20 percent mortality at the highest spore dose, respectively). Interestingly, mucosome inactivation of Bsal zoospores by Michigan newts was lower than Tennessee newts. N. viridescens efts also had higher susceptibility than adult N. viridescens populations. Our results indicate that newt species could play a significant role in the epidemiology of Bsal if it emerges in North America. Moreover, Bsal represents a significant conservation risk to N. meridionalis and N. perstriatus, which are species of greatest conservation need in the southern United States.

Collaborators: 

  • Doug Woodhams
  • Molly Bletz
  • Louise Rollins-Smith 

Funding:

  • University of Tennessee Institute of Agriculture
  • University of Massachusetts-Boston
  • Vanderbilt University

​Transmission pathways and immunological factors driving invasion potential of the recently discovered pathogen, Batrachochytrium salamandrivorans

The current knowledge of Bsal epidemiology is restricted mostly to European fire salamanders, which have different life history strategies than most North American salamander species. This project will parameterize Bsal epidemiological models using controlled experiments with adult and juvenile eastern newts (Notophthalmus viridescens).

This study will be the first to examine the effects of Bsal on a common salamander species with complex life histories and immune responses. This research will expand on the S. salamandra model system by:

  1. Including transmission pathways in both the aquatic and terrestrial environments for a range of ambient temperatures,
  2. Considering two unique forms of infectious Bsal zoospores,
  3. Identifying the role of zoospore persistence in water and soil and factors that affect it,
  4. Explicitly modeling zoospore shedding and between-host transmission as disease progresses, and
  5. Incorporating a recovery stage as an infection outcome.

The study will evaluate immune defenses and anatomical pathology as disease progresses, and it will determine if host resistance or tolerance to Bsal infection is possible. Clinical pathology will be used to identify mechanisms of Bsal pathogenesis, which are currently unknown. This research will significantly advance the foundational knowledge of Bsal epidemiology, immunology, and pathology, and will provide the basis for science-derived disease intervention strategies that are generalizable across similar at-risk species.

Key Questions:

  1. What are the most important transmission pathways that facilitate Bsal invasion, diseased-induced population declines, and pathogen persistence?
  2. What role does life stage play in emergence and persistence of Bsal?
  3. How do mitigation strategies and changes in environmental conditions affect transmission and disease outcomes?
  4. What conditions result in host resistance or tolerance?
  5. What are the mechanisms of pathogenesis?

Collaborators: 

  • Doug Woodhams
  • Louise Rollins-Smith
  • Angie Peace
  • Cherie Briggs
  • Allan Pessier

Funding:

National Science Foundation Logo

US National Science Foundation (Division of Environmental Biology – Ecology of Infectious Diseases Program), Grant #1814520​

Research Objectives

Parameterize a system of ordinary differential equations from empirical data that will identify critical transmission pathways and conditions under which Bsal is likely to emerge in salamander host populations with aquatic and terrestrial life stages.

We will develop a system of ordinary differential equations that: 

  1. Considers susceptibility of juvenile and adult life stages across a range of biologically realistic temperatures, 
  2. Considers shedding, persistence, and encystment rates of two zoospore forms using novel approaches for quantification,
  3. Considers dose-dependent responses of hosts to zoospore concentration in aquatic and terrestrial environments,
  4. Considers probability of transmission given contact by estimating density-dependent contact rates, and
  5. Considers pathogen latency, multiple stages of infection, and a recovered state for host populations.

Outcomes: We will estimate model parameters using empirical data from controlled experiments, and we will simulate dynamics to identify transmission pathways that could drive Bsal epidemics in eastern newt populations. We will estimate the invasion potential (R0) of Bsal into eastern newt populations under differing conditions and incorporate mitigation strategies into experiments that aim to reduce contact rates and environmental persistence of zoospores. Thus, our research will advance the understanding of Bsal epidemioloy by modeling multiple transmission pathways in aquatic and terrestrial environments, allowing transmission probabilities to change as infection progresses to disease, and considering multiple life stages across a range of temperatures biologically realistic to the hosts.

Conceptual model of transmission pathways of eastern newts.
Conceptual model of Bsal transmission pathways with N. viridescens.
Base model for Bsal transmission in N. viridescens for one age class and temperature.
Base model for Bsal transmission in N. viridescens for one age class and temperature.

Quantify innate and adaptive immune responses to Bsal as disease progresses under varying conditions.

Disease develops only when the immune system is unable to recognize or mount an effective response to a pathogen challenge. Objective 2 studies aim to learn more about the immune defenses of vulnerable amphibians against Bsal and determine whether the immune responses differ under varying conditions of temperature and host exposure.

Identify the mechanisms of Bsal pathogenesis and parameterize integral projection models that explore the impacts of host resistance and tolerance on host-pathogen dynamics.

The mechanisms of pathogenesis for Bsal are unknown. Grossly and anatomically, Bsal chytridiomycosis develops differently in a host than Bd. Bd results in hyperkeratosis (i.e., skin thickening), whereas, Bsal causes ulcerative, necrotic skin lesions that can extend through the epidermis. The mechanisms of pathogenesis for Bd are reduction in osmoregulation across the skin that leads to electrolyte imbalance in the blood (especially Na, K, and Ca), which affects the actin-myosin cross-bridge cycle causing paralysis and cardiac arrest. We hypothesize that physiological mechanisms for Bsal pathogenesis will be similar to Bd (i.e., reduction in osmoregulation); however, electrolyte imbalance will be a consequence of skin destruction instead of hyperplasia. It also is possible that reduced cutaneous respiration could be a morbidity factor in Bsal chytridiomycosis. We will use a combination of clinical and anatomical pathology to quantify structural and physiological changes in newts as Bsal chytridiomycosis progresses.

A factor impacting pathogenesis is infection tolerance or the ability of a host to reduce the negative impact of the pathogen on its fitness (i.e., survive infection and limit tissue damage). Integral Projection Models (IPMs) have been used to show that in some amphibian-Bd systems, the potential for disease-induced host extinction was more sensitive to parameters related to host resistance and tolerance than to Bd transmission rates. Bd tends to display highly load-dependent pathology in many amphibian systems, and our experiments will reveal whether this is true for Bsal. Given disease may progress differently among zoospore doses, life stages, and temperatures, this objective will be done in combination with Objective 1.

Histopathology of necrotic ulcerations from Bsal.
Volcano-shaped necrotic ulcerations of Bsal that can extend through the epidermis, likely altering skin function. Image by Allan Pessier.
Line graph showing host resistance and survival of pathogen Bd.
Interaction between the pathogen growth function determining host resistance and the survival function determining host tolerance has large impacts on host survival. Wilber et al. 2017; Ecology Letters 20:1169:1181.

Broader Impacts

This study will inform the European Food Safety Authority of the European Commission, U.S. Fish and Wildlife Service, and other natural resource management agencies on how to combat biodiversity losses due to Bsal. Research briefings will be provided regularly to the North American Bsal Task Force and the Partners in Amphibian and Reptile Conservation. Our results will be shared at national and international scientific meetings, and updates will be posted on this project website. Our team will train biologists about Bsal via workshops and will engage K-12 STEM schools with instructional activities on amphibians and wildlife diseases. This project will train undergraduate, graduate, and veterinary students, postdoctoral research associates, and veterinary medicine residents. Due to the interdisciplinary nature of this research, trainees will be exposed to: design of factorial experiments, compartmental and integral projection models, analysis of complex microbiomes, gross evaluation of animal health, molecular diagnostics, anatomical and clinical pathology, immunology assays, mass spectrometry, flow cytometry, and data entry and analysis. In addition, individual mentoring plans will be developed for postdocs. Students, postdocs, and senior personnel will travel among partnering institutions for professional development and to strengthen cohesiveness of the study objectives.

Collage of young STEM students holding salamanders and learning about the Bsal pathogen.
  • Gray, M. J., and A. C. Peterson. 2019. Salamander diversity and life history in southern Appalachia. Glenwood Elementary (1st grade), Chapel Hill, North Carolina (5/23/19). (video)
  • Gray, M. J. 2019. Skin devouring frogs: The next threat to salamanders and to biodiversity. University of Tennessee Science Forum, Knoxville, TN, 3/29/19. (video)
  • Gray, M. J., D. L. Miller, E. D. Carter, M. Bohanon, D. A. Malagon, and R. Kumar. 2018. Interactive learning with first graders at Clayton Bradley STEM Academy (Alcoa, TN) about amphibian life history (8/21/18).
  • Gray, M. J. 2020. Interview with Jonathan Kolby on pathogen movement in wildlife trade. 5/07/20.
  • Gray, M. J. 2019. Interview with freelance science writer, Kathleen O’Neil, on Bsal invasion risk in the USA. 5/30/19.
  • Gray, M. J. 2019. Batrachochytrium salamandrivorans: Building an understanding of invasion threat in North America with conservation partners. Amphibian Survival Alliance Newsletter, Frogress Report March 2019:1-3.
  • Gray, M. J. 2018.  Interview with freelance science writer, Benji Jones, “On the hunt for a silent salamander killer,” Mongabay, (9/13/18).

  1. Rollins-Smith, L. A. 2020. Global amphibian declines, disease, and the ongoing battle between Batrachochytrium fungi and the immune system. Herpetologica. In Press.
  2. Islam, R. M., M. J. Gray, and A. Peace. 2020 (in press). Identifying the dominant transmission pathway in a multi-stage infection model of the emerging fungal pathogen Batrachochytrium salamandrivorans on the eastern newt. Mathematics of Planet Earth (Infectious Diseases of Our Planet), Springer, New York.
  3. Robinson, K. A., K. E. Pereira, M. C. Bletz, E. D. Carter, M. J. Gray, J. Piovia-Scott, J. M. Romansic, D. C. Woodhams, L. Fritz-Laylin. 2020, Isolation and maintenance of Batrachochytrium salamandrivorans cultures. Disease of Aquatic Organisms (in press).
  4. Malagon, D. A., L. A. Melara, O. F. Proper, S. Lenhart, E. D. Carter, J. A. Fordyce, A. C. Peterson, D. L. Miller, and M. J. Gray. 2020. Host density and habitat structure influence host contact rates and Batrachochytrium salamandrivorans transmission. Scientific Reports 10, 5584. doi.org/10.1038/s41598-020-62351-x. 
  5. Pereira, K. E., M. J. Gray, J. L. Kerby, E. H. Campbell Grant, and J. Voyles. 2020. The next threat: how do we stop fungal disease from devastating North American salamanders? Wildlife Professional 14:41-46.
  6. Ossiboff, R. J., A. E. Towe, M. A. Brown, A. V. Longo, K. R. Lips, D. L. Miller, E. D. Carter, M. J. Gray, and S. Frasca, Jr. 2019. Differentiating Batrachochytrium dendrobatidis and B. salamandrivorans in amphibian chytridiomycosis using RNAScope® in situ hybridization. Frontiers in Veterinary Science 6:304.

In Review:

  1. Wilber, M., E. D. Carter, M. J. Gray, and C. Briggs.  In Review.  Putative resistance and tolerance mechanisms have little impact on disease progression for an emerging salamander pathogen.  Functional Ecology.  
  2. Towe, A., M. J. Gray, E. D. Carter, R. J. Ossiboff, K. Ash, M. Bohanon, B. A. Bajo, and D. L. Miller. In review. Batrachochytrium salamandrivorans can devour more than salamanders. Nature.
  3. Kumar, R., D. A. Malagon, E. D. Carter, M. Bohanon, J. P. Cusaac, A. C. Peterson, D. L. Miller, and M. J. Gray.  In Review.  Experimental methodologies can affect host tolerance to Batrachochytrium salamandrivorans infection. PLOS ONE.  

In Preparation: (for submission prior to Sept 2020)

  1. Carter, E. D., M. Bletz, M. LeSage, L. Rollins-Smith, D. Woodhams, D. L. Miller, and M. J. Gray. Winter is Coming: Temperature Affects Immune Defenses and Susceptibility to Batrachochytrium salamandrivorans. Target Journal = Functional Ecology.
  2. Carter, E. D., D. L. Miller, A. Towe, C. N. Sheets, J. P. W. Cusaac, and M. J. Gray. Estimating Batrachochytrium salamandrivorans zoospore viability using flow cytometry. Target Journal = Diseases of Aquatic Organisms.
  3. Siniard, W. A., Grzelak , M. J. Gray, R. Kumar, K. Ash, C. Cray, E. D. Carter, B. A. Bajo, M. Bohanon, A. C. Peterson, A. Towe, and D. L. Miller. Mechanisms of Batrachochytrium salamandrivorans pathogenesis. Target Journal = Functional Ecology.

University of Tennessee:

Presentations delivered by trained personnel: *denotes presenter.

  1. Bohanon, M.*, D. A. Malagon, L. A. Melara, O. F. Prosper, S. Lenhart, E. D. Carter, D. L. Miller, and M. J. Gray. 2019. Host density and habitat structure influence contact rates and transmission of Batrachochytrium salamandrivorans. University of Tennessee, College of Veterinary Medicine Research Day, Knoxville, Tennessee.
  2. Carter, E.D.*, D. L. Miller, B. A. Bajo, A. Peterson, M. Bohanon, K. Ash, P. Watcharaanantapong, and M. J. Gray. 2020. Winter is coming: Temperature dependent virulence of Batrachochytrium salamandrivorans. 9th World Congress of Herpetology, Otago, Dunedin, New Zealand.
  3. Carter, E.D.*, D. L. Miller, B. A. Bajo, A. Peterson, M. Bohanon, K. Ash, P. Watcharaanantapong, and M. J. Gray. 2019. Winter is coming: Temperature dependent virulence of Batrachochytrium salamandrivorans. American Fisheries Society and The Wildlife Society Joint Conference. Reno, Nevada.
  4. Carter, E.D.*, D. L. Miller, B. A. Bajo, A. Peterson, M. Bohanon, K. Ash, P. Watcharaanantapong, and M. J. Gray. 2019. Winter is coming: Temperature dependent virulence of Batrachochytrium salamandrivorans. 4th Annual UTIA Graduate Student Presentation and Poster Competition. Knoxville, Tennessee.
  5. Carter, E. D.*, D. L. Miller, B. A. Bajo, A. C. Peterson, M. Bohanon, K. Ash, and M. J. Gray.  2019.  Winter is coming: Temperature dependent virulence of Batrachochytrium salamandrivorans.  Ecological Society of America Annual Meeting, Louisville, Kentucky.
  6. Carter, E. D.*, D. L. Miller, B. A. Bajo, A. C. Peterson, M. Bohanon, K. Ash, and M. J. Gray. 2019. Winter is coming: Temperature dependent virulence of Batrachochytrium salamandrivorans. Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Nauvoo, AL.
  7. Malagon, D. A.*, L. A. Melara, O. F. Prosper, S. Lenhart, E. D. Carter, D. L. Miller, and M. J. Gray. 2019. Host density and habitat structure influence contact rates and transmission of Batrachochytrium salamandrivorans. Ecological Society of America Annual Conference, Louisville, Kentucky.
  8. Peterson, A. C.*, M. Bohanon, E. D. Carter, B. A. Bajo, P. Watcharaanantapong*, D. L. Miller, J. G. Surles, and M. J. Gray. 2020. Estimating contact rates of Eastern newts (Notophthalmus viridescens) at differing temperatures, densities and habitat structure. 9th World Congress of Herpetology, Otago, Dunedin, New Zealand.  
  9. Siniard W.*, Towe, A. E., M. J. Gray, E. D. Carter, K. Ash, M. Bohanon, B. A. Bajo, and D. L. Miller. 2019. Batrachochytrium salamandrivorans in the Cuban treefrog (Osteopilus septentrionalis). 4th Annual UTIA Graduate Student Presentation and Poster Competition. Knoxville, Tennessee.
  10. Tompros, A.*, E. D. Carter, A. Fenton, M. Wilber, M. Bohanon, P. Watcharaanantapong, K. Ash, D. L. Miller, and M. J. Gray. 2020. Density-dependent mortality of eastern newts exposed to Batrachochytrium salamandrivorans.  Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Nauvoo, AL.
  11. Towe, A. E.*, M. J. Gray, E. D. Carter, K. Ash, M. Bohanon, B. A. Bajo, and D. L. Miller. 2019. Batrachochytrium salamandrivorans in the Cuban treefrog (Osteopilus septentrionalis). Wildlife Disease Association Annual International Conference, Tahoe City, California.
  12. Towe*, A., D. L. Miller, E. D. Carter, K. Ash, M. Bohanon, B. Bajo, and M. J. Gray.  2020.  Batrachochytrium salamandrivorans in the Cuban tree frogs (Osteopilus septentrionalis).  Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Nauvoo, AL. 
  13. Towe*, A., M. Gray, E. D. Carter, K. Ash, M. Bohanon, B. Bajo, and D. L. Miller.  2020. Batrachochytrium salamandrivorans (Bsal) chytridiomycosis it’s not just for salamanders! 9th World Congress of Herpetology, Otago, Dunedin, New Zealand.
  14. Watcharaanantpong, P.*, B. J. Augustino, E. D. Carter, M. Bohanon, B. A. Bajo, D. A. Malagon, R. Kumar, A. C. Peterson, D. L. Miller, and M. J. Gray. 2019.  Batrachochytrium salamandrivorans devours green salamanders (Aneides aeneus). The Wildlife Society Annual Meeting, Gatlinburg, TN.
  15. Wildmann, A.*, C. Yarber, D. L. Miller, E. D. Carter, A. Peterson, M. J. Gray, and A. Pessier. 2019. Estimating the encystment rate of Batrachochytrium salamandrivorans zoospores in the skin of Eastern Newts. National Veterinary Scholars Symposium, Worcester, MA.
  16. Carter*, E. D., M. J. Gray, J. P. W. Cusaac, A. C. Peterson, L. Rollins-Smith, L. Reinert, M. Bohanon, B. A. Bajo, K. Ash, D. A. Malagon, R. Kumar, B. J. Augustino, L. A. Williams, A. Upchurch, P. Nanjappa, R. N. Harris, and D. L. Miller. 2019. Broad host range of Batrachochytrium salamandrivorans equates to high invasion probability in North America. ZSL Institute of Zoology Amphibian Disease Symposium (Mitigating single pathogen and co-infections that threaten amphibian biodiversity), London, UK, 4/24/19.
  17. Carter*, E. D., D. L. Miller, B. A. Bajo, A. C. Peterson, M. Bohanon, K. Ash, P. Watcharaanantapong, and M. J. Gray. 2019. Winter is coming: Temperature dependent virulence of Batrachochytrium salamandrivorans. ZSL Institute of Zoology Amphibian Disease Symposium (Mitigating single pathogen and co-infections that threaten amphibian biodiversity), London, UK, 4/24/19.
  18. Malagon*, D. A., E. D. Carter, L. Melara, O. F. Prosper, S. Lenhart, D. L. Miller, and M. J. Gray. 2019. Role of density and habitat structure on eastern newt contact rates and Batrachochytrium salamandrivorans transmission. ZSL Institute of Zoology Amphibian Disease Symposium (Mitigating single pathogen and co-infections that threaten amphibian biodiversity). London, UK, 4/24/19.
  19. Augustino*, B., E. D. Carter, M. Bohanon, B. Bajo, P. Watcharaanantapong, D. Malagon, R. Kumar, D. L. Miller, and M. J. Gray. 2019. Batrachochytrium salamadrivorans (Bsal) could decimate green salamanders (Aneides aeneus).  Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Black Mountain, NC, 2/14/19.
  20. Bajo*, B. A., E. D. Carter, M. Bohanon, D. Malagon, B. Augustino, R. Kumar, P. Watcharaanantapong, D. L. Miller, and M. J. Gray. 2019. Changes in eastern newt behavior associated with Batrachochytrium salamandrivorans (Bsal) Chytridiomycosis. Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Black Mountain, NC, 2/14/19.
  21. Carter*, E. D., M. J. Gray, D. L. Miller, M. Bohanon, B. Bajo, and P. W. Cussaac. 2019.  Temperature influences infectivity of Batrachochytrium salamandrivorans (Bsal).  Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Black Mountain, NC, 2/15/19.
  22. Kumar*, R., A. Grezlak, E. D. Carter, M. Bohanon, M. J. Gray, and D. L. Miller. 2019.  More than skin deep: Blood serum protein changes in response to Batrachochytrium salamandrivorans Chytridiomycosis. Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Black Mountain, NC, 2/14/19. 
  23. Malagon*, D. A., L. Melara, O. F. Prosper, S. Lenhart, E. D. Carter, D. L. Miller, and M. J. Gray. 2019. Role of density and habitat structure on eastern newt contact rates and pathogen transmission. Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Black Mountain, NC, 2/16/19.
  24. Towe*, A., O. Ossiboff, M. J. Gray, and D. L. Miller. 2018. Investigating the pathology of Batrachochytrium salamandrivorans in salamanders. University of Tennessee, College of Veterinary Medicine Research Day, Knoxville, TN, 10/02/18.

Presentations at conferences and professional meetings (by PIs):

  1. Gray, M. J.*, E. D. Carter, J. P. W. Cusaac, A. C. Peterson* L. Rollins-Smith, L. Reinert, M. Bohanon, B. A. Bajo, K. Ash, D. A. Malagon, B. Augustino, R. Kumar, L. Williams, A. Upchurch, P. Nanjappa, R. N. Harris, and D. L. Miller. 2020. Broad host range of Batrachochytrium salamandrivorans equates to high invasion probability in North America. 9th World Congress of Herpetology, Otago, Dunedin, New Zealand.
  2. Gray, M. J.*, D. A. Malagon, L. A. Melara, O. F. Prosper, S. Lenhart, J. A. Fordyce, E. D. Carter, A. C. Peterson, and D. L. Miller. 2019. Host density and habitat structure influence contact rates and transmission of Batrachochytrium salamandrivorans.  Joint Meeting of the American Fisheries Society and The Wildlife Society, Reno, NV. September, 2019.  
  3. Gray, M. J.*, E. D. Carter, J. P. W. Cusaac*, A. C. Peterson, L. Rollins- Smith, L. Reinert, M. Bohanon, B. A. Bajo, K. Ash, D. A. Malagon, B. Augustino, R. Kumar, L. Williams, A. Upchurch, P. Nanjappa, R. N. Harris, and D. L. Miller. 2019. Broad host range of Batrachochytrium salamandrivorans equates to high invasion probability in North America.  American Fisheries Society & The Wildlife Society 2019 Joint Annual Conference, Reno, NV.
  4. Grzelak, A., R. Kumar, C. Cray, E. D. Carter, P. Watcharaanantapong, K. Ash, B. A. Bajo, M. Bohanon, A. C. Peterson, M. J. Gray, and D. L. Miller*.  2020. Clinical pathology of Bsal chytridiomycosis: hematological, biochemical, and serum protein analyses of infected Taricha granulosa. 9th World Congress of Herpetology, Otago, Dunedin, New Zealand.  
  5. Grzelak, A., R. Kumar, K. Ash*, E. D. Carter*, B. A. Bajo*, M. Bohanon*, A. C. Peterson*, A. E. Towe, M. J. Gray, and D. L. Miller. 2019. Associating anatomical and clinical pathology with Bsal chytridiomycosis in the rough skinned newt (Taricha granulosa). Wildlife Disease Association International Conference. 
  6. Kerby, J. L., and M. J. Gray. 2019. North American Bsal Task Force – Plans to Prevent an Invasion. Joint Meeting of the American Fisheries Society and The Wildlife Society, Reno, NV.
  7. Miller, D. L.*, A. Grzelak, A. Towe, R. Ossiboff, C. Cray, E. D. Carter, B. Bajo, M. Bohanon, A. Peterson, and M. Gray. 2020. Look, that salamander is being eaten alive! 9th World Congress of Herpetology, Otago, Dunedin, New Zealand.  
  8. Miller, D. L.*, A. K. Grzelak, A. E. Towe, R. Ossiboff, C. Cray, R. Kumar, K. Ash, E. D. Carter, B. A. Bajo, M. Bohanon, A. C. Peterson, and M. J. Gray. 2019. The pathology of Bsal chytridiomycosis: documenting anatomical changes and exploring what they might mean clinically. Joint Meeting of the American Fisheries Society and The Wildlife Society, Reno, NV, September, 2019.  
  9. Piovia-Scott, J.*, E. D. Carter, J. Romansic, J. P. W. Cusaac, L. Rollins- Smith, L. Reinert, D. L. Miller, A. Pessier, R. Harris, P. Nanjappa, L. Williams, A. Upchurch, and M. J. Gray. 2019. Susceptibility of North American Amphibian Species to Batrachochytrium salamandrivorans. Joint Meeting of the American Fisheries Society and The Wildlife Society, Reno, NV. September, 2019.
  10. Gray, M. J. 2019. North American Bsal task force: Plans to prevent an invasion.  Annual Meeting of the Southeast Partners in Amphibian and Reptile Conservation, Black Mountain, NC, 2/15/19. 
  11. Gray, M. J., and M. Bletz. 2018. Batrachochytrium salamandrivorans: The next potential threat to North American biodiversity, Association of Fish and Wildlife Agencies, Fish and Wildlife Health Forum, Reston, VA, 11/14/18.
  12. Gray, M. J. 2018. Ranaviruses and Bsal: Global translocation and emergence through trade, Pet Industry Joint Advisory Council (PIJAC). Washington D.C., 11/01/18. (video)
  13. Gray, M. J., E. D. Carter, M. Bletz, P. Cusaac, D. Woodhams, L. Reinert, L. Rollins-Smith, J. Romansic, J. Piovia-Scott, L. Williams, P. Upchurch, P. Nanjappa, and D. L. Miller. 2018. The threat of Batrachochytrium salamandrivorans (Bsal) to North American amphibian biodiversity: Recent findings and future directions. Arizona State University, Tempe, AZ, 10/27/18.
  14. Gray, M. J. 2018. Role of pathogens in amphibian population declines: Chytrid fungi and ranaviruses. WFS 101 (Current Topics in Wildlife Health), Knoxville, TN, 9/20/18.
  15. Gray, M. J. 2018. Bsal is NOT BS – It is a threat: What can we do? Association of Fish and Wildlife Agencies (Fish and Wildlife Health Committee), Tampa, FL, 9/12/18.
  16. Gray, M. J. 2018. The threat of Batrachochytrium salamandrivorans (Bsal) to North American amphibian biodiversity: Recent findings and future directions.  Association of Fish and Wildlife Agencies (Amphibian and Reptile Conservation Committee), Tampa, FL, 9/11/18.

Texas Tech University:

  1. Md Rafiul Islam presented at the Southeast Center for Mathematics and Biology Symposium 2019 in January 2019 in Atlanta, GA Poster title: Mathematical Modeling and Uncertainty Quantification of Batrachochytrium salamandrivorans on the Eastern Newt.
  2. Md Rafiul Islam presented at the Computational and Mathematical Population Dynamics meeting  5 May 2019 at the Florida Atlantic University Fort Laudardale, FL Talk title: Identifying the Dominant transmission pathway in a multi-stage infection model of the Emerging Fungal Pathogen Batrachochytrium Salamandrivorans on the Eastern Newt.
  3. Md Rafiul Islam presented at the 2019 Annual Meeting and Conference of the Society for Mathematical Biology July 2019 Centre de recherches mathmatiques(CRM), University of Montreal Montreal, QC Talk title: Identifying the Dominant transmission pathway in a multi-stage infection model of the Emerging Fungal Pathogen Batrachochytrium salamandrivorans on the Eastern Newt.
  4. Md Rafiul Islam presented at the Siam Graduate Student Research Day October 2019 to the Department of Mathematics and Statistics, Texas Tech University Lubbock, TX Talk title: Parameter Sensitivity Analysis, Identification of the Dominant Transmission Pathway, and Control Strategies of a Multi-stage Epidemic Model.
  5. Md Rafiul Islam presented at the Seventh International Conference on Mathematical Modeling and Analysis of Populations in Biological Systems October 2019 School of Mathematical and Statistical Sciences, Arizona State University Tempe, AZ Talk title: Mathematical modeling of Batrachochytrium salamandrivorans on the Eastern Newt with multiple transmission pathways.
  6. Angela Peace presented at the AFS and TWS joint annual meeting in Reno Nevada, September 30, 2019. Multiple transmission pathways in Mathematical models of Bsal.

Vanderbilt University:

Invited Lectures (L. Rollins-Smith)

  1. “Amphibian Immunity against Chytrid Fungi-Some Positive News but New Threats to Salamanders.” Southern Illinois University, April 2019.
  2. “Amphibian Immunity against Chytrid Pathogens Linked to Global Amphibian Declines.” Amphibian Declines Symposium. George Washington University, Washington DC, May 2019. Invited speaker.
  3. “Amphibian Immune Defenses against Chytrid Pathogens Linked to Global Amphibian Declines.” International Symposium Amphibian population declines. McGill University. Montreal, Quebec. September 20, 2019. Invited speaker.
  4. “Studies of the Skin Secretions of Eastern Newts in Defense Against Batrachochytrium salamandrivorans.” The Wildlife Society Symposium “Batrachochytrium salamandrivorans: The Next Threat to North American Biodiversity. September 30, 2019. Invited speaker.

Conferences-Platform Talks

  1. Immune defenses of amphibians against Batrachochytrium fungi. Louise A. Rollins-Smith, Laura K. Reinert, Mitchell Le Sage, Thomas Umile, Kevin P.C. Minbiole, E. Davis Carter, Debra L. Miller, and Matthew J. Gray. North American Comparative Immunology Workshop. June 4, 2019. Platform talk.
  2. Skin Secretions of Eastern Newts inhibit Batrachochytrium salamandrivorans. Mitchell Le Sage(Vanderbilt University Medical Center), E. Davis Carter (University of Tennessee), Laura K. Reinert, Debra L. Miller, and Matthew J. Gray, and Louise A. Rollins-Smith. Amphibian Disease Meeting Tempe AZ, November 2019. Platform talk.
  3. Lymphocyte Interactions with Chyrid Fungi: Bd and Bsal compared. Louise A. Rollins-Smith and Laura K. Reinert. Amphibian Disease Meeting Tempe AZ, November 2019. Platform talk.

University of Massachusetts:

  1. Bletz, M. C. Proactive Conservation: Developing Strategies to Combat the Salamander-eating fungus, World Congress of Herpetology, Dunedin, New Zealand. January 2020.
  2. Bletz, M. C. Proactive Conservation: Developing strategies to combat the salamander-eating fungus, The Wildlife Society-Annual Meeting, Reno Nevada. October 2019.
  3. Woodhams, D. C. Testing the Adaptive Microbiome Hypothesis in Eastern Red-Spotted Newts Exposed to Batrachochytrium salamandrivorans. The Wildlife Society-Annual Meeting, Reno Nevada. October 2019.
  4. Woodhams, D. C. The Adaptive Microbiome and Microbial Therapy as a Proactive Response to Disease Emergence. Departmental Seminar, Biology Department, UMASS Boston. September 2019.
  5. Woodhams, D. C. Disease and the Drying Pond: Ecoimmunology of the Amphibian Microbiome. American Society of Microbiology meeting, Boston chapter. Randolph, MA. November, 2019.
  6. Woodhams, D. C, LaBumbard B (presenting). Ecology and Evolution on Amphibian Skin: Responding to Disease Emergence with Microbial Therapy. Evolution for non-biology majors lecture, UMASS Boston. November, 2019.
  7. Woodhams, D. C. The Amphibian Microbiome and Disease Management. IMSD: Research Immersion Project, UMASS Boston. January, 2020.
  8. Woodhams, DC. Amphibian Disease and Tetrodotoxin. Current Literature course, UMASS Boston. April, 2020.

UC-Santa Barbara:

  1. Cherie Briggs presented portions of the Integral Projection Model work at the World Congress of Herpetology meeting in Dunedin, NZ in January 2020.