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Coyle O, Vredenburg VT, Stillman JH. Interactive abiotic and biotic stressor impacts on a stream-dwelling amphibian. Ecol Evol 2024; 14:e11371. [PMID: 38711490 PMCID: PMC11070774 DOI: 10.1002/ece3.11371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/16/2024] [Accepted: 04/19/2024] [Indexed: 05/08/2024] Open
Abstract
Organisms within freshwater and marine environments are subject to a diverse range of often co-occurring abiotic and biotic stressors. Despite growing awareness of the complex multistress systems at play in aquatic ecosystems, many questions remain regarding how simultaneous stressors interact with one another and jointly impact aquatic species. We looked at multistress interactions in a protected stream ecosystem in Mendocino County, California. Specifically, we examined how diurnal temperature variation, turbidity, and predator cues altered the movement speed of larval Pacific giant salamanders (Dicamptodon tenebrosus). In a second experiment, we looked at how simulated low-flow summer conditions impact the expression of heat-shock proteins (HSPs) in the same species. Larvae moved almost one and a half times faster in the presence of chemical cues from trout and suspended sediment, and almost two times faster when both sediment and trout cues were present but were only marginally affected by temperature and visual cues from conspecifics. Interestingly, the order of stressor exposure also appeared to influence larval speed, where exposure to sediment and trout in earlier trials tended to lead to faster speeds in later trials. Additionally, larvae exposed to low-flow conditions had more variable, but not statistically significantly higher, expression of HSPs. Our findings highlight the potential interactive effects of an abiotic stressor, sedimentation, and a biotic stressor, and predator chemical cues on an ecologically important trait: movement speed. Our findings also demonstrate the likely role of HSPs in larval salamander survival in challenging summer conditions. Taken together, these findings show that larval D. tenebrosus responds behaviorally to biotic and abiotic stressors and suggests a possible pathway for physiological tolerance of environmental stress. Consideration of multistress systems and their effects is important for understanding the full effects of co-occurring stressors on aquatic organisms to guide appropriate conservation and management efforts based on ecologically relevant responses of organisms within an environment.
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Affiliation(s)
- Oliver Coyle
- Department of BiologySan Francisco State UniversitySan FranciscoCaliforniaUSA
| | - Vance T. Vredenburg
- Department of BiologySan Francisco State UniversitySan FranciscoCaliforniaUSA
- Museum of Vertebrate ZoologyUniversity of California BerkeleyBerkeleyCaliforniaUSA
| | - Jonathon H. Stillman
- Department of BiologySan Francisco State UniversitySan FranciscoCaliforniaUSA
- Department of Integrative BiologyUniversity of California BerkeleyBerkeleyCaliforniaUSA
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2
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Ghose SL, Yap TA, Byrne AQ, Sulaeman H, Rosenblum EB, Chan-Alvarado A, Chaukulkar S, Greenbaum E, Koo MS, Kouete MT, Lutz K, McAloose D, Moyer AJ, Parra E, Portik DM, Rockney H, Zink AG, Blackburn DC, Vredenburg VT. Continent-wide recent emergence of a global pathogen in African amphibians. Front Conserv Sci 2023. [DOI: 10.3389/fcosc.2023.1069490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023] Open
Abstract
IntroductionEmerging infectious diseases are increasingly recognized as a global threat to wildlife. Pandemics in amphibians, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), have resulted in biodiversity loss at a global scale. Genomic data suggest a complex evolutionary history of Bd lineages that vary in pathogenicity. Africa harbors a significant proportion of global amphibian biodiversity, and multiple Bd lineages are known to occur there; yet, despite the decline of many host species, there are currently no described Bd-epizootics. Here, we describe the historical and recent biogeographical spread of Bd and assess its risk to amphibians across the continent of Africa.MethodsWe provide a 165-year view of host-pathogen interactions by (i) employing a Bd assay to test 4,623 specimens (collected 1908–2013); (ii) compiling 12,297 published Bd records (collected 1852–2017); (iii) comparing the frequency of Bd-infected amphibians through time by both country and region; (iv) genotyping Bd lineages; (v) histologically identifying evidence of chytridiomycosis, and (vi) using a habitat suitability model to assess future Bd risk.ResultsWe found a pattern of Bd emergence beginning largely at the turn of the century. From 1852–1999, we found low Bd prevalence (3.2% overall) and limited geographic spread, but after 2000 we documented a sharp increase in prevalence (18.7% overall), wider geographic spread, and multiple Bd lineages that may be responsible for emergence in different regions. We found that Bd risk to amphibians was highest in much of eastern, central, and western Africa.DiscussionOur study documents a largely overlooked yet significant increase in a fungal pathogen that could pose a threat to amphibians across an entire continent. We emphasize the need to bridge historical and contemporary datasets to better describe and predict host-pathogen dynamics over larger temporal scales.
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Bates KA, Friesen J, Loyau A, Butler H, Vredenburg VT, Laufer J, Chatzinotas A, Schmeller DS. Environmental and Anthropogenic Factors Shape the Skin Bacterial Communities of a Semi-Arid Amphibian Species. Microb Ecol 2022:10.1007/s00248-022-02130-5. [PMID: 36445401 DOI: 10.1007/s00248-022-02130-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
The amphibian skin microbiome is important in maintaining host health, but is vulnerable to perturbation from changes in biotic and abiotic conditions. Anthropogenic habitat disturbance and emerging infectious diseases are both potential disrupters of the skin microbiome, in addition to being major drivers of amphibian decline globally. We investigated how host environment (hydrology, habitat disturbance), pathogen presence, and host biology (life stage) impact the skin microbiome of wild Dhofar toads (Duttaphrynus dhufarensis) in Oman. We detected ranavirus (but not Batrachochytrium dendrobatidis) across all sampling sites, constituting the first report of this pathogen in Oman, with reduced prevalence in disturbed sites. We show that skin microbiome beta diversity is driven by host life stage, water source, and habitat disturbance, but not ranavirus infection. Finally, although trends in bacterial diversity and differential abundance were evident in disturbed versus undisturbed sites, bacterial co-occurrence patterns determined through network analyses revealed high site specificity. Our results therefore provide support for amphibian skin microbiome diversity and taxa abundance being associated with habitat disturbance, with bacterial co-occurrence (and likely broader aspects of microbial community ecology) being largely site specific.
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Affiliation(s)
- K A Bates
- Department of Zoology, University of Oxford, Oxford, UK.
| | - J Friesen
- Centre for Environmental Biotechnology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - A Loyau
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, INPT, UPS, Toulouse, France
| | - H Butler
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - V T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - J Laufer
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - A Chatzinotas
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
- Institute of Biology, Leipzig University, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, Germany
| | - D S Schmeller
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, INPT, UPS, Toulouse, France
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Womack MC, Steigerwald E, Blackburn DC, Cannatella DC, Catenazzi A, Che J, Koo MS, McGuire JA, Ron SR, Spencer CL, Vredenburg VT, Tarvin RD. State of the Amphibia 2020: A Review of Five Years of Amphibian Research and Existing Resources. Ichthyology & Herpetology 2022. [DOI: 10.1643/h2022005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Molly C. Womack
- Department of Biology, Utah State University, Logan, Utah 84322; . ORCID: 0000-0002-3346-021X
| | - Emma Steigerwald
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - David C. Blackburn
- Department of Natural History, Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611; . ORCID: 0000-0002-1810-9886
| | - David C. Cannatella
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712; . ORCID: 0000-0001-8675-0520
| | | | - Jing Che
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China; . ORCID: 0000-0003-4246-6
| | - Michelle S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Jimmy A. McGuire
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Santiago R. Ron
- Museo de Zoología, Escuela de Biología, Pontificia Universidad Católica del Ecuador, Quito, Ecuador; . ORCID: 0000-0001-6300-9350
| | - Carol L. Spencer
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Vance T. Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Rebecca D. Tarvin
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
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Schmeller DS, Cheng T, Shelton J, Lin CF, Chan-Alvarado A, Bernardo-Cravo A, Zoccarato L, Ding TS, Lin YP, Swei A, Fisher MC, Vredenburg VT, Loyau A. Environment is associated with chytrid infection and skin microbiome richness on an amphibian rich island (Taiwan). Sci Rep 2022; 12:16456. [PMID: 36180528 PMCID: PMC9525630 DOI: 10.1038/s41598-022-20547-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 09/14/2022] [Indexed: 11/09/2022] Open
Abstract
Growing evidence suggests that the origins of the panzootic amphibian pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) are in Asia. In Taiwan, an island hotspot of high amphibian diversity, no amphibian mass mortality events linked to Bd or Bsal have been reported. We conducted a multi-year study across this subtropical island, sampling 2517 individuals from 30 species at 34 field sites, between 2010 and 2017, and including 171 museum samples collected between 1981 and 2009. We analyzed the skin microbiome of 153 samples (6 species) from 2017 in order to assess any association between the amphibian skin microbiome and the probability of infection amongst different host species. We did not detect Bsal in our samples, but found widespread infection by Bd across central and northern Taiwan, both taxonomically and spatially. Museum samples show that Bd has been present in Taiwan since at least 1990. Host species, geography (elevation), climatic conditions and microbial richness were all associated with the prevalence of infection. Host life-history traits, skin microbiome composition and phylogeny were associated with lower prevalence of infection for high altitude species. Overall, we observed low prevalence and burden of infection in host populations, suggesting that Bd is enzootic in Taiwan where it causes subclinical infections. While amphibian species in Taiwan are currently threatened by habitat loss, our study indicates that Bd is in an endemic equilibrium with the populations and species we investigated. However, ongoing surveillance of the infection is warranted, as changing environmental conditions may disturb the currently stable equilibrium.
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Affiliation(s)
- Dirk S. Schmeller
- grid.15781.3a0000 0001 0723 035XLaboratoire Ecologie Fonctionnelle et Environnement, Université de Toulouse, INPT, UPS, Toulouse, France
| | - Tina Cheng
- grid.263091.f0000000106792318Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132 USA ,grid.421477.30000 0004 0639 1575Bat Conservation International, Washington, DC USA
| | - Jennifer Shelton
- grid.7445.20000 0001 2113 8111Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG UK
| | - Chun-Fu Lin
- Zoology Division, Endemic Species Research Institute, Jiji, Nantou Taiwan, ROC
| | - Alan Chan-Alvarado
- grid.263091.f0000000106792318Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132 USA
| | - Adriana Bernardo-Cravo
- grid.15781.3a0000 0001 0723 035XLaboratoire Ecologie Fonctionnelle et Environnement, Université de Toulouse, INPT, UPS, Toulouse, France
| | - Luca Zoccarato
- grid.419247.d0000 0001 2108 8097Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, 16775 Stechlin, Germany
| | - Tzung-Su Ding
- grid.19188.390000 0004 0546 0241School of Forestry and Resource Conservation, National Taiwan University, Taipei City, 106 Taiwan, ROC
| | - Yu-Pin Lin
- grid.19188.390000 0004 0546 0241Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan, ROC
| | - Andrea Swei
- grid.263091.f0000000106792318Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132 USA
| | - Matthew C. Fisher
- grid.7445.20000 0001 2113 8111Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG UK
| | - Vance T. Vredenburg
- grid.263091.f0000000106792318Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132 USA ,grid.47840.3f0000 0001 2181 7878Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA 94720 USA
| | - Adeline Loyau
- grid.15781.3a0000 0001 0723 035XLaboratoire Ecologie Fonctionnelle et Environnement, Université de Toulouse, INPT, UPS, Toulouse, France ,grid.419247.d0000 0001 2108 8097Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, 16775 Stechlin, Germany
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García-Sánchez JC, Arredondo-Centeno J, Segovia-Ramírez MG, Tenorio Olvera AM, Parra-Olea G, Vredenburg VT, Rovito SM. Factors Influencing Bacterial and Fungal Skin Communities of Montane Salamanders of Central Mexico. Microb Ecol 2022:10.1007/s00248-022-02049-x. [PMID: 35705744 DOI: 10.1007/s00248-022-02049-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Host microbial communities are increasingly seen as an important component of host health. In amphibians, the first land vertebrates that are threatened by a fungal skin disease globally, our understanding of the factors influencing the microbiome of amphibian skin remains incomplete because recent studies have focused almost exclusively on bacteria, and little information exists on fungal communities associated with wild amphibian species. In this study, we describe the effects of host phylogeny, climate, geographic distance, and infection with a fungal pathogen on the composition and structure of bacterial and fungal communities in seven tropical salamander species that occur in the Trans-Mexican Volcanic Belt of Central Mexico. We find that host phylogenetic relatedness is correlated with bacterial community composition while a composite climatic variable of temperature seasonality and precipitation is significantly associated with fungal community composition. We also estimated co-occurrence networks for bacterial and fungal taxa and found differences in the degree of connectivity and the distribution of negative associations between the two networks. Our results suggest that different factors may be responsible for structuring the bacterial and fungal communities of amphibian skin and that the inclusion of fungi in future studies could shed light on important functional interactions within the microbiome.
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Affiliation(s)
- Julio César García-Sánchez
- Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
| | - José Arredondo-Centeno
- Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
- Instituto Tecnológico Superior de Irapuato, Irapuato, Guanajuato, México
| | - María Guadalupe Segovia-Ramírez
- Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
| | - Ariadna Marcela Tenorio Olvera
- Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
- Instituto Tecnológico Superior de Irapuato, Irapuato, Guanajuato, México
| | - Gabriela Parra-Olea
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de Mexico, México
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
| | - Sean M Rovito
- Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México.
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Haver M, Le Roux G, Friesen J, Loyau A, Vredenburg VT, Schmeller DS. The role of abiotic variables in an emerging global amphibian fungal disease in mountains. Sci Total Environ 2022; 815:152735. [PMID: 34974000 DOI: 10.1016/j.scitotenv.2021.152735] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/23/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
The emergence of the chytridiomycete fungal pathogen Batrachochytrium dendrobatidis (Bd), causing the disease chytridiomycosis, has caused collapse of amphibian communities in numerous mountain systems. The health of amphibians and of mountain freshwater habitats they inhabit is also threatened by ongoing changes in environmental and anthropogenic factors such as climate, hydrology, and pollution. Climate change is causing more extreme climatic events, shifts in ice occurrence, and changes in the timing of snowmelt and pollutant deposition cycles. All of these factors impact both pathogen and host, and disease dynamics. Here we review abiotic variables, known to control Bd occurrence and chytridiomycosis severity, and discuss how climate change may modify them. We propose two main categories of abiotic variables that may alter Bd distribution, persistence, and physiology: 1) climate and hydrology (temperature, precipitation, hydrology, ultraviolet radiation (UVR); and, 2) water chemistry (pH, salinity, pollution). For both categories, we identify topics for further research. More studies on the relationship between global change, pollution and pathogens in complex landscapes, such as mountains, are needed to allow for accurate risk assessments for freshwater ecosystems and resulting impacts on wildlife and human health. Our review emphasizes the importance of using data of higher spatiotemporal resolution and uniform abiotic metrics in order to better compare study outcomes. Fine-scale temperature variability, especially of water temperature, variability of moisture conditions and water levels, snow, ice and runoff dynamics should be assessed as abiotic variables shaping the mountain habitat of pathogen and host. A better understanding of hydroclimate and water chemistry variables, as co-factors in disease, will increase our understanding of chytridiomycosis dynamics.
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Affiliation(s)
- Marilen Haver
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France.
| | - Gaël Le Roux
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France
| | - Jan Friesen
- Environmental and Biotechnology Centre, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Adeline Loyau
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France; Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, Stechlin D-16775, Germany
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - Dirk S Schmeller
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France
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8
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Knapp RA, Joseph MB, Smith TC, Hegeman EE, Vredenburg VT, Erdman Jr JE, Boiano DM, Jani AJ, Briggs CJ. Effectiveness of antifungal treatments during chytridiomycosis epizootics in populations of an endangered frog. PeerJ 2022; 10:e12712. [PMID: 35036095 PMCID: PMC8742549 DOI: 10.7717/peerj.12712] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/09/2021] [Indexed: 01/07/2023] Open
Abstract
The recently-emerged amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has had an unprecedented impact on global amphibian populations, and highlights the urgent need to develop effective mitigation strategies. We conducted in-situ antifungal treatment experiments in wild populations of the endangered mountain yellow-legged frog during or immediately after Bd-caused mass die-off events. The objective of treatments was to reduce Bd infection intensity ("load") and in doing so alter frog-Bd dynamics and increase the probability of frog population persistence despite ongoing Bd infection. Experiments included treatment of early life stages (tadpoles and subadults) with the antifungal drug itraconazole, treatment of adults with itraconazole, and augmentation of the skin microbiome of subadults with Janthinobacterium lividum, a commensal bacterium with antifungal properties. All itraconazole treatments caused immediate reductions in Bd load, and produced longer-term effects that differed between life stages. In experiments focused on early life stages, Bd load was reduced in the 2 months immediately following treatment and was associated with increased survival of subadults. However, Bd load and frog survival returned to pre-treatment levels in less than 1 year, and treatment had no effect on population persistence. In adults, treatment reduced Bd load and increased frog survival over the entire 3-year post-treatment period, consistent with frogs having developed an effective adaptive immune response against Bd. Despite this protracted period of reduced impacts of Bd on adults, recruitment into the adult population was limited and the population eventually declined to near-extirpation. In the microbiome augmentation experiment, exposure of subadults to a solution of J. lividum increased concentrations of this potentially protective bacterium on frogs. However, concentrations declined to baseline levels within 1 month and did not have a protective effect against Bd infection. Collectively, these results indicate that our mitigation efforts were ineffective in causing long-term changes in frog-Bd dynamics and increasing population persistence, due largely to the inability of early life stages to mount an effective immune response against Bd. This results in repeated recruitment failure and a low probability of population persistence in the face of ongoing Bd infection.
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Affiliation(s)
- Roland A. Knapp
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, California, United States
- Earth Research Institute, University of California, Santa Barbara, California, United States
| | | | - Thomas C. Smith
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, California, United States
- Earth Research Institute, University of California, Santa Barbara, California, United States
| | - Ericka E. Hegeman
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, California, United States
- Earth Research Institute, University of California, Santa Barbara, California, United States
| | - Vance T. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, United States
| | - James E. Erdman Jr
- California Department of Fish and Wildlife, Bishop, California, United States
| | - Daniel M. Boiano
- Sequoia and Kings Canyon National Parks, National Park Service, Three Rivers, California, United States
| | - Andrea J. Jani
- Pacific Biosciences Research Center, University of Hawai’i at Mànoa, Honolulu, Hawai’i, United States
| | - Cheryl J. Briggs
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California, United States
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Cowgill M, Zink AG, Sparagon W, Yap TA, Sulaeman H, Koo MS, Vredenburg VT. Social Behavior, Community Composition, Pathogen Strain, and Host Symbionts Influence Fungal Disease Dynamics in Salamanders. Front Vet Sci 2021; 8:742288. [PMID: 34938792 PMCID: PMC8687744 DOI: 10.3389/fvets.2021.742288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/06/2021] [Indexed: 11/29/2022] Open
Abstract
The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), which can cause a fatal disease called chytridiomycosis, is implicated in the collapse of hundreds of host amphibian species. We describe chytridiomycosis dynamics in two co-occurring terrestrial salamander species, the Santa Lucia Mountains slender salamander, Batrachoseps luciae, and the arboreal salamander, Aneides lugubris. We (1) conduct a retrospective Bd-infection survey of specimens collected over the last century, (2) estimate present-day Bd infections in wild populations, (3) use generalized linear models (GLM) to identify biotic and abiotic correlates of infection risk, (4) investigate susceptibility of hosts exposed to Bd in laboratory trials, and (5) examine the ability of host skin bacteria to inhibit Bd in culture. Our historical survey of 2,866 specimens revealed that for most of the early 20th century (~1920–1969), Bd was not detected in either species. By the 1990s the proportion of infected specimens was 29 and 17% (B. luciae and A. lugubris, respectively), and in the 2010s it was 10 and 17%. This was similar to the number of infected samples from contemporary populations (2014–2015) at 10 and 18%. We found that both hosts experience signs of chytridiomycosis and suffered high Bd-caused mortality (88 and 71% for B. luciae and A. lugubris, respectively). Our GLM revealed that Bd-infection probability was positively correlated with intraspecific group size and proximity to heterospecifics but not to abiotic factors such as precipitation, minimum temperature, maximum temperature, mean temperature, and elevation, or to the size of the hosts. Finally, we found that both host species contain symbiotic skin-bacteria that inhibit growth of Bd in laboratory trials. Our results provide new evidence consistent with other studies showing a relatively recent Bd invasion of amphibian host populations in western North America and suggest that the spread of the pathogen may be enabled both through conspecific and heterospecific host interactions. Our results suggest that wildlife disease studies should assess host-pathogen dynamics that consider the interactions and effects of multiple hosts, as well as the historical context of pathogen invasion, establishment, and epizootic to enzootic transitions to better understand and predict disease dynamics.
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Affiliation(s)
- Mae Cowgill
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Andrew G Zink
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Wesley Sparagon
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, UUniversity of Hawai'i at Mānoa, HI, United States
| | - Tiffany A Yap
- Center for Biological Diversity, Oakland, CA, United States
| | - Hasan Sulaeman
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Michelle S Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, United States.,Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
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10
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Koo MS, Vredenburg VT, Deck JB, Olson DH, Ronnenberg KL, Wake DB. Tracking, Synthesizing, and Sharing Global Batrachochytrium Data at AmphibianDisease.org. Front Vet Sci 2021; 8:728232. [PMID: 34692807 PMCID: PMC8527349 DOI: 10.3389/fvets.2021.728232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
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.
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Affiliation(s)
- Michelle S Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
| | - Vance T Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States.,Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - John B Deck
- Berkeley Natural History Museums, University of California, Berkeley, Berkeley, CA, United States
| | - Deanna H Olson
- US Department of Agriculture, Forest Service, Pacific Northwest Research Station, Corvallis, OR, United States
| | - Kathryn L Ronnenberg
- US Department of Agriculture, Forest Service, Pacific Northwest Research Station, Corvallis, OR, United States
| | - David B Wake
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
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11
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Martínez AE, Parra E, Gomez JP, Vredenburg VT. Shared predators between primate groups and mixed species bird flocks: the potential for forest‐wide eavesdropping networks. OIKOS 2021. [DOI: 10.1111/oik.08274] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ari E. Martínez
- Museum of Vertebrate Zoology and Dept of Integrative Biology, Univ. of California Berkeley CA USA
- Dept of Biological Sciences, California State Univ. Long Beach CA USA
| | - Eliseo Parra
- Dept of Biology, San Francisco State Univ. San Francisco CA USA
| | - Juan Pablo Gomez
- Depto de Química y Biología, Univ. del Norte Barranquilla Colombia
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12
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Greer JA, Swei A, Vredenburg VT, Zink AG. Parental Care Alters the Egg Microbiome of Maritime Earwigs. Microb Ecol 2020; 80:920-934. [PMID: 32767092 DOI: 10.1007/s00248-020-01558-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Recruitment of beneficial microbes to protect offspring, often reducing the energetic costs of care, is now recognized as an important component of parental care in many animals. Studies on earwigs (order Dermaptera) have revealed that removal of females from egg tending increases mortality of eggs due to fungal infections, possibly caused by changes in the bacterial microbiome on the egg surface. We used a controlled female-removal experiment to evaluate whether female nest attendance in the maritime earwig, Anisolabis maritima, influences the bacterial microbiome on the egg surface. Further, we analyzed the microbiomes of mothers and their eggs to determine if there are a core set of bacteria transferred to eggs through female care. Microbiomes were analyzed using 16S rRNA bacterial DNA sequencing, revealing that bacterial operational taxonomic unit (OTU) richness and diversity were both significantly higher for female attended versus unattended eggs. The core microbiome of adult females contained bacteria which have the potential to carry anti-fungal characteristics; these bacteria were found in higher presence and relative abundance on eggs where females were allowed to provide care. These results demonstrate that female egg attendance significantly impacts the bacterial microbiome of A. maritima eggs, and identifies specific bacteria within the egg microbiome that should be investigated further for beneficial anti-fungal properties in this system.
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Affiliation(s)
- Jordan A Greer
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA, 94132, USA.
- Committee on Evolutionary Biology, University of Chicago, 5801 S Ellis Ave, Chicago, IL, 60637, USA.
| | - Andrea Swei
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Andrew G Zink
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA, 94132, USA
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13
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Olivares-Miranda M, Vredenburg VT, García-Sánchez JC, Byrne AQ, Rosenblum EB, Rovito SM. Fungal infection, decline and persistence in the only obligate troglodytic Neotropical salamander. PeerJ 2020; 8:e9763. [PMID: 33024623 PMCID: PMC7518159 DOI: 10.7717/peerj.9763] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/28/2020] [Indexed: 01/02/2023] Open
Abstract
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.
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Affiliation(s)
- Mizraim Olivares-Miranda
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - Julio C García-Sánchez
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
| | - Allison Q Byrne
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
| | - Erica B Rosenblum
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
| | - Sean M Rovito
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato, México
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14
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Sette CM, Vredenburg VT, Zink AG. Differences in Fungal Disease Dynamics in Co-occurring Terrestrial and Aquatic Amphibians. Ecohealth 2020; 17:302-314. [PMID: 33237500 DOI: 10.1007/s10393-020-01501-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 09/14/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
The fungal pathogen, Batrachochytrium dendrobatidis (Bd), has devastated biodiversity and ecosystem health and is implicated as a driver of mass amphibian extinctions. This 100-year study investigates which environmental factors contribute to Bd prevalence in a fully terrestrial species, and determines whether infection patterns differ between a fully terrestrial amphibian and more aquatic host species. We performed a historical survey to quantify Bd prevalence in 1127 Batrachoseps gregarius museum specimens collected from 1920 to 2000, and recent data from 16 contemporary (live-caught) B. gregarius populations from the southwestern slopes of the Sierra Nevada mountains in California, USA. We compared these results to Bd detection rates in 1395 historical and 1033 contemporary specimens from 10 species of anurans and 427 historical Taricha salamander specimens collected throughout the Sierra Nevada mountains. Our results indicate that Bd dynamics in the entirely terrestrial species, B. gregarius, differ from aquatic species in the same region in terms of both seasonal patterns of Bd abundance and in the possible timing of Bd epizootics.
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Affiliation(s)
- Carla M Sette
- University of California, Santa Cruz, EEB/CBB mailstop, UCSC/Coastal Biology Building, 130 McAllister Way, Santa Cruz, CA, 95060, USA.
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15
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Bernardo-Cravo AP, Schmeller DS, Chatzinotas A, Vredenburg VT, Loyau A. Environmental Factors and Host Microbiomes Shape Host-Pathogen Dynamics. Trends Parasitol 2020; 36:616-633. [PMID: 32402837 DOI: 10.1016/j.pt.2020.04.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/11/2020] [Accepted: 04/11/2020] [Indexed: 12/18/2022]
Abstract
Microorganisms are increasingly recognized as ecosystem-relevant components because they affect the population dynamics of hosts. Functioning at the interface of the host and pathogen, skin and gut microbiomes are vital components of immunity. Recent work reveals a strong influence of biotic and abiotic environmental factors (including the environmental microbiome) on disease dynamics, yet the importance of the host-host microbiome-pathogen-environment interaction has been poorly reflected in theory. We use amphibians and the disease chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis to show how interactions between host, host microbiome, pathogen, and the environment all affect disease outcome. Our review provides new perspectives that improve our understanding of disease dynamics and ecology by incorporating environmental factors and microbiomes into disease theory.
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Affiliation(s)
- Adriana P Bernardo-Cravo
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Dirk S Schmeller
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| | - Antonis Chatzinotas
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstrasse 15, 04318, Leipzig, Germany; Leipzig University, Institute of Biology, Johannisallee 21-23, 04103 Leipzig, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Adeline Loyau
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, Stechlin, D-16775, Germany
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16
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Lambert MR, Womack MC, Byrne AQ, Hernández-Gómez O, Noss CF, Rothstein AP, Blackburn DC, Collins JP, Crump ML, Koo MS, Nanjappa P, Rollins-Smith L, Vredenburg VT, Rosenblum EB. Comment on "Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity". Science 2020; 367:367/6484/eaay1838. [PMID: 32193293 DOI: 10.1126/science.aay1838] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 02/18/2020] [Indexed: 01/12/2023]
Abstract
Scheele et al (Reports, 29 March 2019, p. 1459) bring needed attention to the effects of amphibian infectious disease. However, the data and methods implicating the disease chytridiomycosis in 501 amphibian species declines are deficient. Which species are affected, and how many, remains a critical unanswered question. Amphibians are imperiled; protective actions require public support and robust science.
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Affiliation(s)
- Max R Lambert
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA.
| | - Molly C Womack
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA.,National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Allison Q Byrne
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA.,Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Obed Hernández-Gómez
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA
| | - Clay F Noss
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA.,Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Andrew P Rothstein
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA.,Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - David C Blackburn
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - James P Collins
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Martha L Crump
- Department of Biology and Ecology Center, Utah State University, Logan, UT 84322, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Michelle S Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Priya Nanjappa
- Conservation Science Partners, Fort Collins, CO 80524, USA
| | - Louise Rollins-Smith
- Departments of Pathology, Microbiology and Immunology, and Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | - Vance T Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA.,Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Erica B Rosenblum
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA.,Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
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17
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Woodhams DC, Rollins-Smith LA, Reinert LK, Lam BA, Harris RN, Briggs CJ, Vredenburg VT, Patel BT, Caprioli RM, Chaurand P, Hunziker P, Bigler L. Probiotics Modulate a Novel Amphibian Skin Defense Peptide That Is Antifungal and Facilitates Growth of Antifungal Bacteria. Microb Ecol 2020; 79:192-202. [PMID: 31093727 DOI: 10.1007/s00248-019-01385-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/25/2019] [Indexed: 06/09/2023]
Abstract
Probiotics can ameliorate diseases of humans and wildlife, but the mechanisms remain unclear. Host responses to interventions that change their microbiota are largely uncharacterized. We applied a consortium of four natural antifungal bacteria to the skin of endangered Sierra Nevada yellow-legged frogs, Rana sierrae, before experimental exposure to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). The probiotic microbes did not persist, nor did they protect hosts, and skin peptide sampling indicated immune modulation. We characterized a novel skin defense peptide brevinin-1Ma (FLPILAGLAANLVPKLICSITKKC) that was downregulated by the probiotic treatment. Brevinin-1Ma was tested against a range of amphibian skin cultures and found to inhibit growth of fungal pathogens Bd and B. salamandrivorans, but enhanced the growth of probiotic bacteria including Janthinobacterium lividum, Chryseobacterium ureilyticum, Serratia grimesii, and Pseudomonas sp. While commonly thought of as antimicrobial peptides, here brevinin-1Ma showed promicrobial function, facilitating microbial growth. Thus, skin exposure to probiotic bacterial cultures induced a shift in skin defense peptide profiles that appeared to act as an immune response functioning to regulate the microbiome. In addition to direct microbial antagonism, probiotic-host interactions may be a critical mechanism affecting disease resistance.
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Affiliation(s)
- Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA.
| | - Louise A Rollins-Smith
- Departments of Pathology, Microbiology and Immunology and Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- Department of Biological Science, Vanderbilt University School of Medicine, Nashville, TN, 37235, USA
| | - Laura K Reinert
- Departments of Pathology, Microbiology and Immunology and Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Briana A Lam
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Reid N Harris
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Cheryl J Briggs
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106-9610, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, 94132-1722, USA
| | - Bhumi T Patel
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - Richard M Caprioli
- Mass Spectrometry Research Center and Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232-8575, USA
| | - Pierre Chaurand
- Department of Chemistry, Université de Montréal, Montreal, QC, H3T 1J4, Canada
| | - Peter Hunziker
- Functional Genomics Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Laurent Bigler
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
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18
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De León ME, Zumbado-Ulate H, García-Rodríguez A, Alvarado G, Sulaeman H, Bolaños F, Vredenburg VT. Batrachochytrium dendrobatidis infection in amphibians predates first known epizootic in Costa Rica. PLoS One 2019; 14:e0208969. [PMID: 31821326 PMCID: PMC6903748 DOI: 10.1371/journal.pone.0208969] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 10/18/2019] [Indexed: 11/19/2022] Open
Abstract
Emerging infectious diseases are a growing threat to biodiversity worldwide. Outbreaks of the infectious disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), are implicated in 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 presence in 1016 anuran museum specimens collected throughout Costa Rica. The earliest specimen that tested positive for Bd was collected in 1964. Across all time periods, we found an overall infection rate (defined as the proportion of Bd-positive individuals) of 4%. The number of infected individuals remained relatively low across all species tested and the range of Bd-positive specimens was shown to be geographically constrained up until the 1980s; when epizootics are hypothesized to have occurred. After that time, infection rate increased three-fold, and the range of specimens tested positive for Bd increased, with Bd-positive specimens collected across the entire country. Our results suggest that Bd dynamics in Costa Rica are more complicated than previously thought. The discovery of Bd's presence in the country preceding massive declines leads to a number of different hypotheses: 1) Bd invaded Costa Rica earlier than previously known, and spread more slowly than previously reported; 2) Bd invaded multiple times and faded out; 3) an endemic Bd lineage existed; 4) an earlier Bd lineage evolved into the current Bd lineage or hybridized with an invasive lineage; or 5) an earlier Bd lineage went extinct and a new invasion event occurred causing epizootics. 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 the most plausible spatial-temporal, host-pathogen dynamics that could best explain the epizootics resulting in amphibian declines in Costa Rica and throughout Central America.
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Affiliation(s)
- Marina E. De León
- Department of Microbiology and Molecular genetics, University of California, Davis, United States of America
| | - Héctor Zumbado-Ulate
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States of America
| | - Adrián García-Rodríguez
- Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gilbert Alvarado
- Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
| | - Hasan Sulaeman
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Federico Bolaños
- Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Vance T. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
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19
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Brown C, Wilkinson LR, Wilkinson KK, Tunstall T, Foote R, Todd BD, Vredenburg VT. Demography, Habitat, and Movements of the Sierra Nevada Yellow-Legged Frog (Rana sierrae) in Streams. COPEIA 2019. [DOI: 10.1643/ce-19-196] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Cathy Brown
- Stanislaus National Forest, USDA Forest Service, 19777 Greenley Rd., Sonora, California 95370; (CB) ; (LRW) ; and (KKW) . Send reprint requests to CB
| | - Lucas R. Wilkinson
- Stanislaus National Forest, USDA Forest Service, 19777 Greenley Rd., Sonora, California 95370; (CB) ; (LRW) ; and (KKW) . Send reprint requests to CB
| | - Kathryn K. Wilkinson
- Stanislaus National Forest, USDA Forest Service, 19777 Greenley Rd., Sonora, California 95370; (CB) ; (LRW) ; and (KKW) . Send reprint requests to CB
| | - Tate Tunstall
- FocusVision 7 River Park Pl E #110, Fresno, California 93720;
| | - Ryan Foote
- Chattahoochee–Oconee National Forest, USDA Forest Service, 9975 Hwy 441 S., Lakemont, Georgia 30552;
| | - Brian D. Todd
- Wildlife, Fish, and Conservation Biology, University of California, One Shields Avenue, Davis, California 95616;
| | - Vance T. Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, California 94132;
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20
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Byrne AQ, Vredenburg VT, Martel A, Pasmans F, Bell RC, Blackburn DC, Bletz MC, Bosch J, Briggs CJ, Brown RM, Catenazzi A, Familiar López M, Figueroa-Valenzuela R, Ghose SL, Jaeger JR, Jani AJ, Jirku M, Knapp RA, Muñoz A, Portik DM, Richards-Zawacki CL, Rockney H, Rovito SM, Stark T, Sulaeman H, Tao NT, Voyles J, Waddle AW, Yuan Z, Rosenblum EB. Cryptic diversity of a widespread global pathogen reveals expanded threats to amphibian conservation. Proc Natl Acad Sci U S A 2019; 116:20382-20387. [PMID: 31548391 PMCID: PMC6789904 DOI: 10.1073/pnas.1908289116] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Biodiversity loss is one major outcome of human-mediated ecosystem disturbance. One way that humans have triggered wildlife declines is by transporting disease-causing agents to remote areas of the world. Amphibians have been hit particularly hard by disease due in part to a globally distributed pathogenic chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Prior research has revealed important insights into the biology and distribution of Bd; however, there are still many outstanding questions in this system. Although we know that there are multiple divergent lineages of Bd that differ in pathogenicity, we know little about how these lineages are distributed around the world and where lineages may be coming into contact. Here, we implement a custom genotyping method for a global set of Bd samples. This method is optimized to amplify and sequence degraded DNA from noninvasive skin swab samples. We describe a divergent lineage of Bd, which we call BdASIA3, that appears to be widespread in Southeast Asia. This lineage co-occurs with the global panzootic lineage (BdGPL) in multiple localities. Additionally, we shed light on the global distribution of BdGPL and highlight the expanded range of another lineage, BdCAPE. Finally, we argue that more monitoring needs to take place where Bd lineages are coming into contact and where we know little about Bd lineage diversity. Monitoring need not use expensive or difficult field techniques but can use archived swab samples to further explore the history-and predict the future impacts-of this devastating pathogen.
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Affiliation(s)
- Allison Q Byrne
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Ghent University, 9820 Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Ghent University, 9820 Merelbeke, Belgium
| | - Rayna C Bell
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington DC 20560
- Department of Herpetology, California Academy of Sciences, San Francisco, CA 94118
| | - David C Blackburn
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32601
| | - Molly C Bletz
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125
| | - Jaime Bosch
- Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Cientificas (CSIC), 28006 Madrid, Spain
- Research Unit of Biodiversity, CSIC-Universidad de Oviedo-Gobierno del Principado de Asturias, E-33600 Mieres, Spain
| | - Cheryl J Briggs
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106
| | - Rafe M Brown
- University of Kansas Biodiversity Institute, University of Kansas, Lawrence, KS 66045
- Department of Ecology and Evolution, University of Kansas, Lawrence, KS 66045
| | - Alessandro Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL 33199
| | - Mariel Familiar López
- School of Environment and Sciences, Griffith University, Gold Coast, QLD 4215, Australia
| | | | - Sonia L Ghose
- Department of Evolution and Ecology, University of California, Davis, CA 95616
| | - Jef R Jaeger
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154
| | - Andrea J Jani
- Department of Oceanography, University of Hawai'i at Manoa, Honolulu, HI 96822
| | - Miloslav Jirku
- Institute of Parasitology, Czech Academy of Sciences, 370 05 Ceske Budejovice, Czech Republic
| | - Roland A Knapp
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, CA 93546
| | - Antonio Muñoz
- Department of Biodiversity Conservation, El Colegio de la Frontera Sur, San Cristobal de las Casas, Chiapas 29290, México
| | - Daniel M Portik
- Department of Ecology and Evolution, University of Arizona, Tucson, AZ 85721
| | | | - Heidi Rockney
- Environmental Sciences Graduate Program, Oregon State University, Corvallis, OR 97331
| | - Sean M Rovito
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato CP36824, México
| | - Tariq Stark
- Reptile, Amphibian and Fish Conservation, 6525 ED Nijmegen, The Netherlands
| | - Hasan Sulaeman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Nguyen Thien Tao
- Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, NV 89557
| | - Anthony W Waddle
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154
- One Health Research Group, The University of Melbourne, Werribee, VIC 3030, Australia
| | - Zhiyong Yuan
- College of Forestry, Southwest Forestry University, Kunming 650224, Yunnan, China
| | - Erica Bree Rosenblum
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720;
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720
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21
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Vredenburg VT, McNally SVG, Sulaeman H, Butler HM, Yap T, Koo MS, Schmeller DS, Dodge C, Cheng T, Lau G, Briggs CJ. Pathogen invasion history elucidates contemporary host pathogen dynamics. PLoS One 2019; 14:e0219981. [PMID: 31536501 PMCID: PMC6752790 DOI: 10.1371/journal.pone.0219981] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 07/05/2019] [Indexed: 01/23/2023] Open
Abstract
Amphibians, the most threatened group of vertebrates, are seen as indicators of the sixth mass extinction on earth. Thousands of species are threatened with extinction and many have been affected by an emerging infectious disease, chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis (Bd). However, amphibians exhibit different responses to the pathogen, such as survival and population persistence with infection, or mortality of individuals and complete population collapse after pathogen invasion. Multiple factors can affect host pathogen dynamics, yet few studies have provided a temporal view that encompasses both the epizootic phase (i.e. pathogen invasion and host collapse), and the transition to a more stable co-existence (i.e. recovery of infected host populations). In the Sierra Nevada mountains of California, USA, conspecific populations of frogs currently exhibit dramatically different host/ Bd-pathogen dynamics. To provide a temporal context by which present day dynamics may be better understood, we use a Bd qPCR assay to test 1165 amphibian specimens collected between 1900 and 2005. Our historical analyses reveal a pattern of pathogen invasion and eventual spread across the Sierra Nevada over the last century. Although we found a small number of Bd-infections prior to 1970, these showed no sign of spread or increase in infection prevalence over multiple decades. After the late 1970s, when mass die offs were first noted, our data show Bd as much more prevalent and more spatially spread out, suggesting epizootic spread. However, across the ~400km2 area, we found no evidence of a wave-like pattern, but instead discovered multiple, nearly-simultaneous invasions within regions. We found that Bd invaded and spread in the central Sierra Nevada (Yosemite National Park area) about four decades before it invaded and spread in the southern Sierra Nevada (Sequoia and Kings Canyon National Parks area), and suggest that the temporal pattern of pathogen invasion may help explain divergent contemporary host pathogen dynamics.
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Affiliation(s)
- Vance T. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
| | - Samuel V. G. McNally
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Hasan Sulaeman
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Helen M. Butler
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Tiffany Yap
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, California, United States of America
- Center for Biological Diversity, Oakland, California, United States of America
| | - Michelle S. Koo
- Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, California, United States of America
| | | | - Celeste Dodge
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Tina Cheng
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Gordon Lau
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Cheryl J. Briggs
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
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22
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Ellison S, Rovito S, Parra-Olea G, Vásquez-Almazán C, Flechas SV, Bi K, Vredenburg VT. The Influence of Habitat and Phylogeny on the Skin Microbiome of Amphibians in Guatemala and Mexico. Microb Ecol 2019; 78:257-267. [PMID: 30467714 DOI: 10.1007/s00248-018-1288-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 11/06/2018] [Indexed: 06/09/2023]
Abstract
Microbial symbionts are increasingly recognized as playing a critical role in organismal health across a wide range of hosts. Amphibians are unique hosts in that their skin helps to regulate the exchange of water, ions, and gases, and it plays an active role in defense against pathogens through the synthesis of anti-microbial peptides. The microbiome of amphibian skin includes a diverse community of bacteria known to defend against pathogens, including the global pandemic lineage of Batrachochytrium dendrobatidis associated with mass amphibian die-offs. The relative influence of host phylogeny and environment in determining the composition of the amphibian skin microbiome remains poorly understood. We collected skin swabs from montane amphibians in Mexico and Guatemala, focusing on two genera of plethodontid salamanders and one genus of frogs. We used high throughput sequencing to characterize the skin bacterial microbiome and tested the impact of phylogeny and habitat on bacterial diversity. Our results show that phylogenetic history strongly influences the diversity and community structure of the total bacterial microbiome at higher taxonomic levels (between orders), but on lower scales (within genera and species), the effect of habitat predominates. These results add to a growing consensus that habitat exerts a strong effect on microbiome structure and composition, particularly at shallow phylogenetic scales.
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Affiliation(s)
- Silas Ellison
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
| | - Sean Rovito
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720, USA.
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36824, Irapuato, Guanajuato, Mexico.
| | - Gabriela Parra-Olea
- Departamento de Zoología, Insituto de Biología, Universidad Nacional Autónoma de México, CP04510, México, DF, Mexico
| | - Carlos Vásquez-Almazán
- Museo de Historia Natural y Escuela de Biología, Universidad de San Carlos, Guatemala, Guatemala
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, AA 4976, Bogotá, Colombia
- Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá, Colombia
| | - Ke Bi
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720, USA
- Computational Genomics Resource Laboratory, California Institute for Quantitative Biosciences University of California, Berkeley, CA, 94720, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720, USA
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23
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Zumbado‐Ulate H, García‐Rodríguez A, Vredenburg VT, Searle C. Infection with Batrachochytrium dendrobatidis is common in tropical lowland habitats: Implications for amphibian conservation. Ecol Evol 2019; 9:4917-4930. [PMID: 31031954 PMCID: PMC6476760 DOI: 10.1002/ece3.5098] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 02/25/2019] [Accepted: 02/28/2019] [Indexed: 11/24/2022] Open
Abstract
Numerous species of amphibians declined in Central America during the 1980s and 1990s. These declines mostly affected highland stream amphibians and have been primarily linked to chytridiomycosis, a deadly disease caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Since then, the majority of field studies on Bd in the Tropics have been conducted in midland and highland environments (>800 m) mainly because the environmental conditions of mountain ranges match the range of ideal abiotic conditions for Bd in the laboratory. This unbalanced sampling has led researchers to largely overlook host-pathogen dynamics in lowlands, where other amphibian species declined during the same period. We conducted a survey testing for Bd in 47 species (n = 348) in four lowland sites in Costa Rica to identify local host-pathogen dynamics and to describe the abiotic environment of these sites. We detected Bd in three sampling sites and 70% of the surveyed species. We found evidence that lowland study sites exhibit enzootic dynamics with low infection intensity and moderate to high prevalence (55% overall prevalence). Additionally, we found evidence that every study site represents an independent climatic zone, where local climatic differences may explain variations in Bd disease dynamics. We recommend more detection surveys across lowlands and other sites that have been historically considered unsuitable for Bd occurrence. These data can be used to identify sites for potential disease outbreaks and amphibian rediscoveries.
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Affiliation(s)
| | - Adrián García‐Rodríguez
- Departamento de Zoología, Instituto de BiologíaUniversidad Nacional Autónoma de México (UNAM)Ciudad de MéxicoMéxico
- Escuela de BiologíaUniversidad de Costa RicaSan JoséCosta Rica
- Departamento de EcologiaUniversidade Federal do Rio Grande do NorteNatalBrazil
| | | | - Catherine Searle
- Department of Biological SciencesPurdue UniversityWest LafayetteIndiana
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24
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Ellison S, Knapp RA, Sparagon W, Swei A, Vredenburg VT. Reduced skin bacterial diversity correlates with increased pathogen infection intensity in an endangered amphibian host. Mol Ecol 2018; 28:127-140. [PMID: 30506592 DOI: 10.1111/mec.14964] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 09/28/2018] [Accepted: 10/30/2018] [Indexed: 12/13/2022]
Abstract
The fungal pathogen Batrachochytrium dendrobatidis (Bd) infects the skin of amphibians and has caused severe declines and extinctions of amphibians globally. In this study, we investigate the interaction between Bd and the bacterial skin microbiome of the endangered Sierra Nevada yellow-legged frog, Rana sierrae, using both culture-dependent and culture-independent methods. Samples were collected from two populations of R. sierrae that likely underwent Bd epizootics in the past, but that continue to persist with Bd in an enzootic disease state, and we address the hypothesis that such "persistent" populations are aided by mutualistic skin microbes. Our 16S rRNA metabarcoding data reveal that the skin microbiome of highly infected juvenile frogs is characterized by significantly reduced species richness and evenness, and by strikingly lower variation between individuals, compared to juveniles and adults with lower infection levels. Over 90% of DNA sequences from the skin microbiome of highly infected frogs were derived from bacteria in a single order, Burkholderiales, compared to just 54% in frogs with lower infection levels. In a culture-dependent Bd inhibition assay, the bacterial metabolites we evaluated all inhibited the growth of Bd. Together, these results illustrate the disruptive effects of Bd infection on host skin microbial community structure and dynamics, and suggest possible avenues for the development of anti-Bd probiotic treatments.
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Affiliation(s)
- Silas Ellison
- Department of Biology, San Francisco State University, San Francisco, California
| | - Roland A Knapp
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, California
| | - Wesley Sparagon
- Department of Biology, Whitman College, Walla Walla, Washington
| | - Andrea Swei
- Department of Biology, San Francisco State University, San Francisco, California
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California.,Museum of Vertebrate Zoology, University of California, Berkeley, California
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25
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Abstract
Animal distributions are influenced by variation in predation risk in space, which has been described as the "landscape of fear." Many studies suggest animals also reduce predation risk by eavesdropping on heterospecific alarm calls, allowing them to occupy otherwise risky habitats. One unexplored area of study is understanding how different species' alarms vary in quality, and how this variation is distributed in the landscape. We tested this phenomenon in a unique system of avian mixed species flocks in Amazonian rainforests: flock mates (eavesdropping species) strongly associate with alarm-calling antshrikes (genus Thamnomanes), which act as sentinel species. Up to 70 species join these flocks, presumably following antshrike behavioral cues. Since flocks in this region of the Amazon are exclusively led by a single antshrike species, this provides a unique natural system to compare differences in sentinel quality between flocks. We simulated predation threat by flying three species of live trained raptors (predators) towards flocks to compare sentinel probability to (1) produce alarm calls, and (2) encode information about magnitude and type of threat within such alarm calls. Our field experiments show significant differences in the probability of different sentinel species to produce alarm calls and distinguish predators. This variation may have important fitness consequences and shape the "landscape of fear" for eavesdropping species.
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Affiliation(s)
- A E Martínez
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, USA
| | - E Parra
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, USA
| | - L F Collado
- Colka Raptors SAC, Mza. C Lote 10-L Urb. San Eduardo Piura, Piura, Peru
| | - V T Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, USA
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26
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Flechas SV, Acosta-González A, Escobar LA, Kueneman JG, Sánchez-Quitian ZA, Parra-Giraldo CM, Rollins-Smith LA, Reinert LK, Vredenburg VT, Amézquita A, Woodhams DC. Microbiota and skin defense peptides may facilitate coexistence of two sympatric Andean frog species with a lethal pathogen. ISME J 2018; 13:361-373. [PMID: 30254321 DOI: 10.1038/s41396-018-0284-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 08/21/2018] [Accepted: 08/23/2018] [Indexed: 12/13/2022]
Abstract
Management of hyper-virulent generalist pathogens is an emergent global challenge, yet for most disease systems we lack a basic understanding as to why some host species suffer mass mortalities, while others resist epizootics. We studied two sympatric species of frogs from the Colombian Andes, which coexist with the amphibian pathogen Batrachochytrium dendrobatidis (Bd), to understand why some species did not succumb to the infection. We found high Bd prevalence in juveniles for both species, yet infection intensities remained low. We also found that bacterial community composition and host defense peptides are specific to amphibian life stages. We detected abundant Bd-inhibitory skin bacteria across life stages and Bd-inhibitory defense peptides post-metamorphosis in both species. Bd-inhibitory bacteria were proportionally more abundant in adults of both species than in earlier developmental stages. We tested for activity of peptides against the skin microbiota and found that in general peptides did not negatively affect bacterial growth and in some instances facilitated growth. Our results suggest that symbiotic bacteria and antimicrobial peptides may be co-selected for, and that together they contribute to the ability of Andean amphibian species to coexist with the global pandemic lineage of Bd.
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Affiliation(s)
- Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, Bogotá, 111711, Colombia. .,Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá, Colombia.
| | | | - Laura A Escobar
- Department of Microbiology, Faculty of Sciences, Pontificia Universidad Javeriana, Bogotá, AA 56710, Colombia
| | - Jordan G Kueneman
- Biology Department, University of Massachusetts Boston, Boston, MA, 02125, USA.,Smithsonian Tropical Research Institute, Panama, Apartado 0843-03092, Republic of Panama
| | - Zilpa Adriana Sánchez-Quitian
- Department of Microbiology, Faculty of Sciences, Pontificia Universidad Javeriana, Bogotá, AA 56710, Colombia.,Environmental Management Group, Department of Biology and Microbiology, Universidad de Boyacá, Tunja, 150000003, Colombia
| | - Claudia M Parra-Giraldo
- Department of Microbiology, Faculty of Sciences, Pontificia Universidad Javeriana, Bogotá, AA 56710, Colombia
| | - Louise A Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA
| | - Laura K Reinert
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, 94132-1722, USA
| | - Adolfo Amézquita
- Department of Biological Sciences, Universidad de los Andes, Bogotá, 111711, Colombia
| | - Douglas C Woodhams
- Biology Department, University of Massachusetts Boston, Boston, MA, 02125, USA.,Smithsonian Tropical Research Institute, Panama, Apartado 0843-03092, Republic of Panama
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27
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Martínez AE, Parra E, Muellerklein O, Vredenburg VT. Fear-based niche shifts in neotropical birds. Ecology 2018; 99:1338-1346. [PMID: 29787637 DOI: 10.1002/ecy.2217] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 01/18/2018] [Accepted: 02/09/2018] [Indexed: 11/09/2022]
Abstract
Predation is a strong ecological force that shapes animal communities through natural selection. Recent studies have shown the cascading effects of predation risk on ecosystems through changes in prey behavior. Minimizing predation risk may explain why multiple prey species associate together in space and time. For example, mixed-species flocks that have been widely documented from forest systems, often include birds that eavesdrop on sentinel species (alarm calling heterospecifics). Sentinel species may be pivotal in (1) allowing flocking species to forage in open areas within forests that otherwise incur high predation risk, and (2) influencing flock occurrence (the amount of time species spend with a flock). To test this, we conducted a short-term removal experiment in an Amazonian lowland rainforest to test whether flock habitat use and flock occurrence was influenced by sentinel presence. Antshrikes (genus Thamnomanes) act as sentinels in Amazonian mixed-species flocks by providing alarm calls widely used by other flock members. The alarm calls provide threat information about ambush predators such as hawks and falcons which attack in flight. We quantified home range behavior, the forest vegetation profile used by flocks, and the proportion occurrence of other flocking species, both before and after removal of antshrikes from flocks. We found that when sentinel species were removed, (1) flock members shifted habitat use to lower risk habitats with greater vegetation cover, and (2) species flock occurrence decreased. We conclude that eavesdropping on sentinel species may allow other species to expand their realized niche by allowing them to safely forage in high-risk habitats within the forest. In allowing species to use extended parts of the forest, sentinel species may influence overall biodiversity across a diverse landscape.
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Affiliation(s)
- Ari E Martínez
- Department of Biology, San Francisco State University, San Francisco, California, 94132, USA
| | - Eliseo Parra
- Department of Biology, San Francisco State University, San Francisco, California, 94132, USA
| | - Oliver Muellerklein
- Department of Environmental, Science, Policy and Management, University of California, Berkeley, California, 94720, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, 94132, USA
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28
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Schmeller DS, Loyau A, Bao K, Brack W, Chatzinotas A, De Vleeschouwer F, Friesen J, Gandois L, Hansson SV, Haver M, Le Roux G, Shen J, Teisserenc R, Vredenburg VT. People, pollution and pathogens - Global change impacts in mountain freshwater ecosystems. Sci Total Environ 2018; 622-623:756-763. [PMID: 29223902 DOI: 10.1016/j.scitotenv.2017.12.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/01/2017] [Accepted: 12/01/2017] [Indexed: 05/06/2023]
Abstract
Mountain catchments provide for the livelihood of more than half of humankind, and have become a key destination for tourist and recreation activities globally. Mountain ecosystems are generally considered to be less complex and less species diverse due to the harsh environmental conditions. As such, they are also more sensitive to the various impacts of the Anthropocene. For this reason, mountain regions may serve as sentinels of change and provide ideal ecosystems for studying climate and global change impacts on biodiversity. We here review different facets of anthropogenic impacts on mountain freshwater ecosystems. We put particular focus on micropollutants and their distribution and redistribution due to hydrological extremes, their direct influence on water quality and their indirect influence on ecosystem health via changes of freshwater species and their interactions. We show that those changes may drive pathogen establishment in new environments with harmful consequences for freshwater species, but also for the human population. Based on the reviewed literature, we recommend reconstructing the recent past of anthropogenic impact through sediment analyses, to focus efforts on small, but highly productive waterbodies, and to collect data on the occurrence and variability of microorganisms, biofilms, plankton species and key species, such as amphibians due to their bioindicator value for ecosystem health and water quality. The newly gained knowledge can then be used to develop a comprehensive framework of indicators to robustly inform policy and decision making on current and future risks for ecosystem health and human well-being.
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Affiliation(s)
- Dirk S Schmeller
- Helmholtz Centre for Environmental Research - UFZ, Department of Conservation Biology, Permoserstrasse 15, 04318 Leipzig, Germany; ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| | - Adeline Loyau
- Helmholtz Centre for Environmental Research - UFZ, Department of Conservation Biology, Permoserstrasse 15, 04318 Leipzig, Germany; ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Helmholtz Centre for Environmental Research - UFZ, Department of System Ecotoxicology, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Kunshan Bao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, East Beijing Road 73, 210008 Nanjing, China
| | - Werner Brack
- Helmholtz Centre for Environmental Research - UFZ, Department of Effect-Directed Analysis, Permoserstrasse 15, 04318 Leipzig, Germany; RWTH Aachen University, Department of Ecosystem Analysis, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany
| | - Antonis Chatzinotas
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstrasse 15, 04318 Leipzig, Germany
| | | | - Jan Friesen
- Helmholtz Centre for Environmental Research - UFZ, Department of Catchment Hydrology, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Laure Gandois
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Sophia V Hansson
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Aarhus University, Department of Bioscience - Arctic Research Centre, Fredriksborgvej 399, 4000 Roskilde, Denmark
| | - Marilen Haver
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Gaël Le Roux
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Ji Shen
- Helmholtz Centre for Environmental Research - UFZ, Department of System Ecotoxicology, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Roman Teisserenc
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Vance T Vredenburg
- San Francisco State University, Department of Biology, 1600 Holloway Ave, San Francisco, CA 94132, USA
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29
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Yap TA, Koo MS, Ambrose RF, Vredenburg VT. Introduced bullfrog facilitates pathogen invasion in the western United States. PLoS One 2018; 13:e0188384. [PMID: 29659568 PMCID: PMC5901863 DOI: 10.1371/journal.pone.0188384] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 11/06/2017] [Indexed: 11/22/2022] Open
Abstract
Batrachochytrium dendrobatidis (Bd), a causal agent of the amphibian fungal skin disease chytridiomycosis, has been implicated in the decline and extinction of over 200 species worldwide since the 1970s. Despite almost two decades of research, the history of Bd and its global spread is not well understood. However, the spread of the Global Panzootic Lineage of Bd (Bd-GPL), the lineage associated with amphibian die-offs, has been linked with the American bullfrog (Rana [Aqurana] catesbeiana) and global trade. Interestingly, R. catesbeiana is native to the eastern U.S., where no Bd-related declines have been observed despite Bd’s presence since the late 1800s. In contrast Bd has been found to have emerged in California and Mexico in the 1960s and 1970s, after which epizootics (i.e., epidemics in wildlife) ensued. We hypothesize that Bd-GPL spread from the eastern U.S. with the introduction of R. catesbeiana into the western US, resulting in epizootics and declines of native host species. Using museum records, we investigated the historical relationship between R. catesbeiana and Bd invasion in the western US and found that R. catesbeiana arrived in the same year or prior to Bd in most western watersheds that had data for both species, suggesting that Bd-GPL may have originated in the eastern US and R. catesbeiana may have facilitated Bd invasion in the western US. To predict areas with greatest suitability for Bd, we created a suitability model by integrating habitat suitability and host availability. When we incorporated invasion history with high Bd suitability, we found that watersheds with non-native R. catesbeiana in the mountain ranges of the West Coast have the highest disease risk. These findings shed light on the invasion history and disease dynamics of Bd in North America. Targeted historical surveys using archived specimens in natural history collections and present-day field surveys along with more localized, community-level studies, monitoring, and surveillance are needed to further test this hypothesis and grow our understanding of the disease ecology and host-pathogen dynamics of Bd.
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Affiliation(s)
- Tiffany A. Yap
- Institute of the Environment and Sustainability, University of California, Los Angeles, California, United States of America
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Michelle S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
| | - Richard F. Ambrose
- Institute of the Environment and Sustainability, University of California, Los Angeles, California, United States of America
- Department of Environmental Health Sciences, University of California, Los Angeles, California, United States of America
| | - Vance T. Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- * E-mail:
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30
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Catenazzi A, Flechas SV, Burkart D, Hooven ND, Townsend J, Vredenburg VT. Widespread Elevational Occurrence of Antifungal Bacteria in Andean Amphibians Decimated by Disease: A Complex Role for Skin Symbionts in Defense Against Chytridiomycosis. Front Microbiol 2018; 9:465. [PMID: 29593698 PMCID: PMC5861192 DOI: 10.3389/fmicb.2018.00465] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 02/28/2018] [Indexed: 12/23/2022] Open
Abstract
Emerging infectious disease is a growing threat to global health, and recent discoveries reveal that the microbiota dwelling on and within hosts can play an important role in health and disease. To understand the capacity of skin bacteria to protect amphibian hosts from the fungal disease chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd), we isolated 192 bacterial morphotypes from the skin of 28 host species of frogs (families Bufonidae, Centrolenidae, Hemiphractidae, Hylidae, Leptodactylidae, Strabomantidae, and Telmatobiidae) collected from the eastern slopes of the Peruvian Andes (540-3,865 m a.s.l.) in the Kosñipata Valley near Manu National Park, a site where we previously documented the collapse of montane frog communities following chytridiomycosis epizootics. We obtained isolates through agar culture from skin swabs of wild frogs, and identified bacterial isolates by comparing 16S rRNA sequences against the GenBank database using BLAST. We identified 178 bacterial strains of 38 genera, including 59 bacterial species not previously reported from any amphibian host. The most common bacterial isolates were species of Pseudomonas, Paenibacillus, Chryseobacterium, Comamonas, Sphingobacterium, and Stenotrophomonas. We assayed the anti-fungal abilities of 133 bacterial isolates from 26 frog species. To test whether cutaneous bacteria might inhibit growth of the fungal pathogen, we used a local Bd strain isolated from the mouthparts of stream-dwelling tadpoles (Hypsiboas gladiator, Hylidae). We quantified Bd-inhibition in vitro with co-culture assays. We found 20 bacterial isolates that inhibited Bd growth, including three isolates not previously known for such inhibitory abilities. Anti-Bd isolates occurred on aquatic and terrestrial breeding frogs across a wide range of elevations (560-3,695 m a.s.l.). The inhibitory ability of anti-Bd isolates varied considerably. The proportion of anti-Bd isolates was lowest at mid-elevations (6%), where amphibian declines have been steepest, and among hosts that are highly susceptible to chytridiomycosis (0-14%). Among non-susceptible species, two had the highest proportion of anti-Bd isolates (40 and 45%), but one common and non-susceptible species had a low proportion (13%). In conclusion, we show that anti-Bd bacteria are widely distributed elevationally and phylogenetically across frog species that have persisted in a region where chytridiomycosis emerged, caused a devastating epizootic and continues to infect amphibians.
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Affiliation(s)
- Alessandro Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL, United States.,Department of Zoology, Southern Illinois University, Carbondale, IL, United States
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de Los Andes, Bogotá, Colombia
| | - David Burkart
- Department of Zoology, Southern Illinois University, Carbondale, IL, United States
| | - Nathan D Hooven
- Department of Zoology, Southern Illinois University, Carbondale, IL, United States
| | - Joseph Townsend
- Department of Zoology, Southern Illinois University, Carbondale, IL, United States
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, United States
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31
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Bird AK, Prado-Irwin SR, Vredenburg VT, Zink AG. Skin Microbiomes of California Terrestrial Salamanders Are Influenced by Habitat More Than Host Phylogeny. Front Microbiol 2018; 9:442. [PMID: 29593686 PMCID: PMC5861191 DOI: 10.3389/fmicb.2018.00442] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 02/26/2018] [Indexed: 02/01/2023] Open
Abstract
A multitude of microorganisms live on and within plant and animal hosts, yet the ecology and evolution of these microbial communities remains poorly understood in many taxa. This study examined the extent to which environmental factors and host taxonomic identity explain microbiome variation within two salamander genera, Ensatina and Batrachoseps, in the family Plethodontidae. In particular, we assessed whether microbiome differentiation paralleled host genetic distance at three levels of taxonomy: genus and high and low clade levels within Ensatina eschscholtzii. We predicted that more genetically related host populations would have more similar microbiomes than more distantly related host populations. We found that salamander microbiomes possess bacterial species that are most likely acquired from their surrounding soil environment, but the relative representation of those bacterial species is significantly different on the skin of salamanders compared to soil. We found differences in skin microbiome alpha diversity among Ensatina higher and lower clade groups, as well as differences between Ensatina and Batrachoseps. We also found that relative microbiome composition (beta diversity) did vary between Ensatina lower clades, but differences were driven by only a few clades and not correlated to clade genetic distances. We conclude this difference was likely a result of Ensatina lower clades being associated with geographic location and habitat type, as salamander identity at higher taxonomic levels (genus and Ensatina higher clades) was a weak predictor of microbiome composition. These results lead us to conclude that environmental factors are likely playing a more significant role in salamander cutaneous microbiome assemblages than host-specific traits.
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Affiliation(s)
- Alicia K Bird
- Department of Biology, San Francisco State University, San Francisco, CA, United States.,Department of Evolution and Ecology, University of California, Davis, Davis, CA, United States
| | - Sofia R Prado-Irwin
- Department of Biology, San Francisco State University, San Francisco, CA, United States.,Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Andrew G Zink
- Department of Biology, San Francisco State University, San Francisco, CA, United States
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32
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Owens MT, Trujillo G, Seidel SB, Harrison CD, Farrar KM, Benton HP, Blair JR, Boyer KE, Breckler JL, Burrus LW, Byrd DT, Caporale N, Carpenter EJ, Chan YHM, Chen JC, Chen L, Chen LH, Chu DS, Cochlan WP, Crook RJ, Crow KD, de la Torre JR, Denetclaw WF, Dowdy LM, Franklin D, Fuse M, Goldman MA, Govindan B, Green M, Harris HE, He ZH, Ingalls SB, Ingmire P, Johnson ARB, Knight JD, LeBuhn G, Light TL, Low C, Lund L, Márquez-Magaña LM, Miller-Sims VC, Moffatt CA, Murdock H, Nusse GL, Parker VT, Pasion SG, Patterson R, Pennings PS, Ramirez JC, Ramirez RM, Riggs B, Rohlfs RV, Romeo JM, Rothman BS, Roy SW, Russo-Tait T, Sehgal RNM, Simonin KA, Spicer GS, Stillman JH, Swei A, Timpe LC, Vredenburg VT, Weinstein SL, Zink AG, Kelley LA, Domingo CR, Tanner KD. Collectively Improving Our Teaching: Attempting Biology Department-wide Professional Development in Scientific Teaching. CBE Life Sci Educ 2018; 17:ar2. [PMID: 29326102 PMCID: PMC6007775 DOI: 10.1187/cbe.17-06-0106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/23/2017] [Accepted: 11/06/2017] [Indexed: 05/10/2023]
Abstract
Many efforts to improve science teaching in higher education focus on a few faculty members at an institution at a time, with limited published evidence on attempts to engage faculty across entire departments. We created a long-term, department-wide collaborative professional development program, Biology Faculty Explorations in Scientific Teaching (Biology FEST). Across 3 years of Biology FEST, 89% of the department's faculty completed a weeklong scientific teaching institute, and 83% of eligible instructors participated in additional semester-long follow-up programs. A semester after institute completion, the majority of Biology FEST alumni reported adding active learning to their courses. These instructor self-reports were corroborated by audio analysis of classroom noise and surveys of students in biology courses on the frequency of active-learning techniques used in classes taught by Biology FEST alumni and nonalumni. Three years after Biology FEST launched, faculty participants overwhelmingly reported that their teaching was positively affected. Unexpectedly, most respondents also believed that they had improved relationships with departmental colleagues and felt a greater sense of belonging to the department. Overall, our results indicate that biology department-wide collaborative efforts to develop scientific teaching skills can indeed attract large numbers of faculty, spark widespread change in teaching practices, and improve departmental relations.
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Affiliation(s)
- Melinda T Owens
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Gloriana Trujillo
- Office of the Vice Provost for Teaching and Learning, Stanford University, Stanford, CA 94305
| | - Shannon B Seidel
- Department of Biology, Pacific Lutheran University, Tacoma, WA 98447
| | - Colin D Harrison
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Katherine M Farrar
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Hilary P Benton
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - J R Blair
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Katharyn E Boyer
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Jennifer L Breckler
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Laura W Burrus
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Dana T Byrd
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Natalia Caporale
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA 95616
| | - Edward J Carpenter
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Yee-Hung M Chan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joseph C Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lily Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Linda H Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Diana S Chu
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - William P Cochlan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Robyn J Crook
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Karen D Crow
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - José R de la Torre
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Wilfred F Denetclaw
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lynne M Dowdy
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Darleen Franklin
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Megumi Fuse
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Michael A Goldman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Brinda Govindan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Michael Green
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Holly E Harris
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Zheng-Hui He
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Stephen B Ingalls
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Peter Ingmire
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Division of Undergraduate Education and Academic Planning, San Francisco State University, San Francisco, CA 94132
| | - Amber R B Johnson
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jonathan D Knight
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Gretchen LeBuhn
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Terrye L Light
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Candace Low
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lance Lund
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | | | | | - Heather Murdock
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Gloria L Nusse
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - V Thomas Parker
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sally G Pasion
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Robert Patterson
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Pleuni S Pennings
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Julio C Ramirez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Robert M Ramirez
- College of Science and Engineering, San Francisco State University, San Francisco, CA 94132
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Rori V Rohlfs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joseph M Romeo
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Barry S Rothman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Scott W Roy
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Tatiane Russo-Tait
- Department of Curriculum and Instruction, STEM Education, University of Texas at Austin, Austin, TX 78712
| | - Ravinder N M Sehgal
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Kevin A Simonin
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Greg S Spicer
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jonathon H Stillman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Andrea Swei
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Leslie C Timpe
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Department of Mathematics, San Francisco State University, San Francisco, CA 94132
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Steven L Weinstein
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Andrew G Zink
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Loretta A Kelley
- Kelley, Petterson, and Associates, Inc., San Francisco, CA 94127
| | - Carmen R Domingo
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- College of Science and Engineering, San Francisco State University, San Francisco, CA 94132
| | - Kimberly D Tanner
- Department of Biology, San Francisco State University, San Francisco, CA 94132
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33
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Familiar López M, Rebollar EA, Harris RN, Vredenburg VT, Hero JM. Temporal Variation of the Skin Bacterial Community and Batrachochytrium dendrobatidis Infection in the Terrestrial Cryptic Frog Philoria loveridgei. Front Microbiol 2017; 8:2535. [PMID: 29312226 PMCID: PMC5744006 DOI: 10.3389/fmicb.2017.02535] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 12/06/2017] [Indexed: 12/31/2022] Open
Abstract
In animals and plants, symbiotic bacteria can play an important role in disease resistance of host and are the focus of much current research. Globally, amphibian population declines and extinctions have occurred due to chytridiomycosis, a skin disease caused by the pathogen Batrachochytrium dendrobatidis (Bd). Currently amphibian skin bacteria are increasingly recognized as important symbiont communities with a relevant role in the defense against pathogens, as some bacteria can inhibit the growth of B. dendrobatidis. This study aims to document the B. dendrobatidis infection status of wild populations of a terrestrial cryptic frog (Philoria loveridgei), and to determine whether infection status is correlated with changes in the skin microbial communities. Skin samples of P. loveridgei were collected along an altitudinal range within the species distribution in subtropical rainforests in southeast Australia. Sampling was conducted in two years during two breeding seasons with the first classified as a “La Niña” year. We used Taqman real-time PCR to determine B. dendrobatidis infection status and 16S amplicon sequencing techniques to describe the skin community structure. We found B. dendrobatidis-positive frogs only in the second sampling year with low infection intensities, and no correlation between B. dendrobatidis infection status and altitude, frog sex or size. Skin bacterial diversity was significantly higher in P. loveridgei frogs sampled in the 1st year than in the 2nd year. In addition, 7.4% of the total OTUs were significantly more abundant in the 1st year compared to the 2nd year. We identified 67 bacterial OTUs with a significant positive correlation between infection intensity and an OTU’s relative abundance. Forty-five percent of these OTUs belonged to the family Enterobacteriaceae. Overall, temporal variation was strongly associated with changes in B. dendrobatidis infection status and bacterial community structure of wild populations of P. loveridgei.
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Affiliation(s)
- Mariel Familiar López
- Environmental Futures Research Institute, School of Environment, Griffith University, Gold Coast, QLD, Australia
| | - Eria A Rebollar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Reid N Harris
- Department of Biology, James Madison University, Harrisonburg, VA, United States.,Amphibian Survival Alliance, London, United Kingdom
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Jean-Marc Hero
- Environmental Futures Research Institute, School of Environment, Griffith University, Gold Coast, QLD, Australia.,School of Science and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia
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34
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Yap TA, Nguyen NT, Serr M, Shepack A, Vredenburg VT. Batrachochytrium salamandrivorans and the Risk of a Second Amphibian Pandemic. Ecohealth 2017; 14:851-864. [PMID: 29147975 DOI: 10.1007/s10393-017-1278-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/07/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
Amphibians are experiencing devastating population declines globally. A major driver is chytridiomycosis, an emerging infectious disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Bd was described in 1999 and has been linked with declines since the 1970s, while Bsal is a more recently discovered pathogen that was described in 2013. It is hypothesized that Bsal originated in Asia and spread via international trade to Europe, where it has been linked to salamander die-offs. Trade in live amphibians thus represents a significant threat to global biodiversity in amphibians. We review the current state of knowledge regarding Bsal and describe the risk of Bsal spread. We discuss regional responses to Bsal and barriers that impede a rapid, coordinated global effort. The discovery of a second deadly emerging chytrid fungal pathogen in amphibians poses an opportunity for scientists, conservationists, and governments to improve global biosecurity and further protect humans and wildlife from a growing number of emerging infectious diseases.
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Affiliation(s)
- Tiffany A Yap
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Avenue, San Francisco, CA, 94132, USA.
- Museum of Vertebrate Zoology, University of California Berkeley, 3101 Valley Life Sciences Building, Berkeley, CA, 94720, USA.
| | - Natalie T Nguyen
- U.S. Geological Survey National Wildlife Health Center, 6006 Schroeder Rd., Madison, WI, 53711, USA
| | - Megan Serr
- Department of Biological Sciences, North Carolina State University, Thomas Hall, 1100 Brooks Avenue, Raleigh, NC, 27695, USA
| | - Alexander Shepack
- Zoology Department, Southern Illinois University Carbondale, 1125 Lincoln Drive, Carbondale, IL, 62901, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
- Museum of Vertebrate Zoology, University of California Berkeley, 3101 Valley Life Sciences Building, Berkeley, CA, 94720, USA
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35
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Prado-Irwin SR, Bird AK, Zink AG, Vredenburg VT. Intraspecific Variation in the Skin-Associated Microbiome of a Terrestrial Salamander. Microb Ecol 2017; 74:745-756. [PMID: 28466089 PMCID: PMC5909955 DOI: 10.1007/s00248-017-0986-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 04/18/2017] [Indexed: 05/28/2023]
Abstract
Resident microbial communities living on amphibian skin can have significant effects on host health, yet the basic ecology of the host-microbiome relationship of many amphibian taxa is poorly understood. We characterized intraspecific variation in the skin microbiome of the salamander Ensatina eschscholtzii xanthoptica, a subspecies composed of four genetically distinct populations distributed throughout the San Francisco Bay Area and the Sierra Nevada mountains in California, USA. We found that salamanders from four geographically and genetically isolated populations harbor similar skin microbial communities, which are dominated by a common core set of bacterial taxa. Additionally, within a population, the skin microbiome does not appear to differ significantly between salamanders of different ages or sexes. In all cases, the salamander skin microbiomes were significantly different from those of the surrounding terrestrial environment. These results suggest that the relationship between E. e. xanthoptica salamanders and their resident skin microbiomes is conserved, possibly indicating a stable mutualism between the host and microbiome.
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Affiliation(s)
- Sofia R Prado-Irwin
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA.
| | - Alicia K Bird
- Department of Evolution and Ecology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Andrew G Zink
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
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36
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Jaeger JR, Waddle AW, Rivera R, Harrison DT, Ellison S, Forrest MJ, Vredenburg VT, van Breukelen F. Batrachochytrium dendrobatidis and the Decline and Survival of the Relict Leopard Frog. Ecohealth 2017; 14:285-295. [PMID: 28439781 DOI: 10.1007/s10393-017-1240-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 06/07/2023]
Abstract
Epizootic disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is a major driver of amphibian declines, yet many amphibians declined before the pathogen was described. The Relict Leopard Frog, Rana onca (=Lithobates onca), was nearly extinct, with the exception of populations within a few geothermal springs. Growth of Bd, however, is limited by high water temperature, and geothermal springs may have provided refuge during outbreaks of chytridiomycosis. We conducted field surveys and laboratory experiments to assess the susceptibility of R. onca to Bd. In the field, we found Bd at one of the two areas where remnant populations of R. onca still occur, but not in the other. In the laboratory, we infected juvenile frogs from these two areas with two hypervirulent Bd isolates associated with declines in other ranid species. In our experiments, these Bd isolates did not affect survivorship of R. onca and most infections (64%) were cleared by the end of the experiments. We propose that R. onca either has inherent resistance to Bd or has recently evolved such resistance. These results may be important for conservation efforts aimed at establishing new populations of R. onca across a landscape where Bd exists. Resistance, however, varies among life stages, and we also did not assess Bd from the local environment. We caution that the resistance we observed for young frogs under laboratory conditions may not translate to the situation for R. onca in the wild.
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Affiliation(s)
- Jef R Jaeger
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA.
| | - Anthony W Waddle
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
| | - Rebeca Rivera
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
| | - D Tyler Harrison
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
| | - Silas Ellison
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, USA
| | | | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, USA
| | - Frank van Breukelen
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
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Romansic JM, Johnson JE, Wagner RS, Hill RH, Gaulke CA, Vredenburg VT, Blaustein AR. Complex interactive effects of water mold, herbicide, and the fungus Batrachochytrium dendrobatidis on Pacific treefrog Hyliola regilla hosts. Dis Aquat Organ 2017; 123:227-238. [PMID: 28322209 DOI: 10.3354/dao03094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Infectious diseases pose a serious threat to global biodiversity. However, their ecological impacts are not independent of environmental conditions. For example, the pathogenic fungus Batrachochytrium dendrobatidis (Bd), which has contributed to population declines and extinctions in many amphibian species, interacts with several environmental factors to influence its hosts, but potential interactions with other pathogens and environmental contaminants are understudied. We examined the combined effects of Bd, a water mold (Achlya sp.), and the herbicide Roundup® Regular (hereafter, Roundup®) on larval Pacific treefrog Hyliola regilla hosts. We employed a 2 wk, fully factorial laboratory experiment with 3 ecologically realistic levels (0, 1, and 2 mg l-1 of active ingredient) of field-formulated Roundup®, 2 Achlya treatments (present and absent), and 2 Bd treatments (present and absent). Our results were consistent with sublethal interactive effects involving all 3 experimental factors. When Roundup® was absent, the proportion of Bd-exposed larvae infected with Bd was elevated in the presence of Achlya, consistent with Achlya acting as a synergistic cofactor that facilitated the establishment of Bd infection. However, this Achlya effect became nonsignificant at 1 mg l-1 of the active ingredient of Roundup® and disappeared at the highest Roundup® concentration. In addition, Roundup® decreased Bd loads among Bd-exposed larvae. Our study suggests complex interactive effects of a water mold and a contaminant on Bd infection in amphibian hosts. Achlya and Roundup® were both correlated with altered patterns of Bd infection, but in different ways, and Roundup® appeared to remove the influence of Achlya on Bd.
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Affiliation(s)
- John M Romansic
- Department of Integrative Biology, 3029 Cordley Hall, Oregon State University, Corvallis, Oregon 97331, USA
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Adams AJ, Kupferberg SJ, Wilber MQ, Pessier AP, Grefsrud M, Bobzien S, Vredenburg VT, Briggs CJ. Extreme drought, host density, sex, and bullfrogs influence fungal pathogen infection in a declining lotic amphibian. Ecosphere 2017. [DOI: 10.1002/ecs2.1740] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Andrea J. Adams
- Department of Ecology, Evolution, and Marine Biology; University of California; Santa Barbara California 93106 USA
| | - Sarah J. Kupferberg
- Department of Integrative Biology; University of California; Berkeley California 94720 USA
| | - Mark Q. Wilber
- Department of Ecology, Evolution, and Marine Biology; University of California; Santa Barbara California 93106 USA
| | - Allan P. Pessier
- Department of Veterinary Microbiology and Pathology; College of Veterinary Medicine; Washington State University; Pullman Washington 99164 USA
| | - Marcia Grefsrud
- California Department of Fish and Wildlife; Bay Delta Region Napa California 94558 USA
| | - Steve Bobzien
- East Bay Regional Park District; Oakland California 94605 USA
| | | | - Cheryl J. Briggs
- Department of Ecology, Evolution, and Marine Biology; University of California; Santa Barbara California 93106 USA
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De León ME, Vredenburg VT, Piovia-Scott J. Recent Emergence of a Chytrid Fungal Pathogen in California Cascades Frogs (Rana cascadae). Ecohealth 2017; 14:155-161. [PMID: 27957606 DOI: 10.1007/s10393-016-1201-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 11/02/2016] [Accepted: 11/03/2016] [Indexed: 06/06/2023]
Abstract
The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with global amphibian declines, but it is often difficult to discern the relative importance of Bd as a causal agent in declines that have already occurred. Retrospective analyses of museum specimens have allowed researchers to associate the timing of Bd arrival with the timing of past amphibian declines. Cascades frogs (Rana cascadae) have experienced dramatic declines in northern California, but it is not clear whether the onset of these declines corresponds to the arrival of Bd. We used quantitative real-time PCR assays of samples collected from museum specimens to determine historical Bd prevalence in the northern California range of Cascades frogs. We detected Bd in 13 of 364 (3.5%) Cascades frog specimens collected between 1907 and 2003, with the first positive result from 1978. A Bayesian analysis suggested that Bd arrived in the region between 1973 and 1978, which corresponds well with the first observations of declines in the 1980s.
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Affiliation(s)
- Marina E De León
- Department of Biology, California State Polytechnic University, Pomona, Pomona, CA, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - Jonah Piovia-Scott
- School of Biological Sciences, Washington State University, 14204 NE Salmon Creek Avenue, Vancouver, WA, 98686, USA.
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Yap TA, Gillespie L, Ellison S, Flechas SV, Koo MS, Martinez AE, Vredenburg VT. Invasion of the Fungal Pathogen Batrachochytrium dendrobatidis on California Islands. Ecohealth 2016; 13:145-150. [PMID: 26493624 DOI: 10.1007/s10393-015-1071-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Abstract
Batrachochytrium dendrobatidis (Bd), an amphibian fungal pathogen, has infected >500 species and caused extinctions or declines in >200 species worldwide. Despite over a decade of research, little is known about its invasion biology. To better understand this, we conducted a museum specimen survey (1910-1997) of Bd in amphibians on 11 California islands and found a pattern consistent with the emergence of Bd epizootics on the mainland, suggesting that geographic isolation did not prevent Bd invasion. We propose that suitable habitat, host diversity, and human visitation overcome isolation from the mainland and play a role in Bd invasion.
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Affiliation(s)
- Tiffany A Yap
- Institute of the Environment and Sustainability, University of California, La Kretz Hall, Suite 300, 619 Charles E Young Drive, Los Angeles, CA, 90095, USA
- Museum of Vertebrate Zoology, University of California, 3101 Valley Life Sciences Building #3160, Berkeley, CA, 94720, USA
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Lauren Gillespie
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Silas Ellison
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, Bogotá, AA 4976, Colombia
| | - Michelle S Koo
- Museum of Vertebrate Zoology, University of California, 3101 Valley Life Sciences Building #3160, Berkeley, CA, 94720, USA
| | - Ari E Martinez
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Vance T Vredenburg
- Museum of Vertebrate Zoology, University of California, 3101 Valley Life Sciences Building #3160, Berkeley, CA, 94720, USA.
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA.
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Warne RW, LaBumbard B, LaGrange S, Vredenburg VT, Catenazzi A. Co-Infection by Chytrid Fungus and Ranaviruses in Wild and Harvested Frogs in the Tropical Andes. PLoS One 2016; 11:e0145864. [PMID: 26726999 PMCID: PMC4701007 DOI: 10.1371/journal.pone.0145864] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/09/2015] [Indexed: 11/18/2022] Open
Abstract
While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd), undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv) also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globally, or how co-infections with Bd impact amphibians are poorly understood. We provide the first report of Bd and Rv co-infection in South America, and the first report of Rv infections in the amphibian biodiversity hotspot of the Peruvian Andes, where Bd is associated with extinctions. Using these data, we tested the hypothesis that Bd or Rv parasites facilitate co-infection, as assessed by parasite abundance or infection intensity within individual adult frogs. Co-infection occurred in 30% of stream-dwelling frogs; 65% were infected by Bd and 40% by Rv. Among terrestrial, direct-developing Pristimantis frogs 40% were infected by Bd, 35% by Rv, and 20% co-infected. In Telmatobius frogs harvested for the live-trade 49% were co-infected, 92% were infected by Bd, and 53% by Rv. Median Bd and Rv loads were similar in both wild (Bd = 101.2 Ze, Rv = 102.3 viral copies) and harvested frogs (Bd = 103.1 Ze, Rv = 102.7 viral copies). While neither parasite abundance nor infection intensity were associated with co-infection patterns in adults, these data did not include the most susceptible larval and metamorphic life stages. These findings suggest Rv distribution is global and that co-infection among these parasites may be common. These results raise conservation concerns, but greater testing is necessary to determine if parasite interactions increase amphibian vulnerability to secondary infections across differing life stages, and constitute a previously undetected threat to declining populations. Greater surveillance of parasite interactions may increase our capacity to contain and mitigate the impacts of these and other wildlife diseases.
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Affiliation(s)
- Robin W. Warne
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
- * E-mail:
| | - Brandon LaBumbard
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
| | - Seth LaGrange
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
| | - Vance T. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, United States of America
| | - Alessandro Catenazzi
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
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Affiliation(s)
- Tiffany A Yap
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA, USA. Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA. Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - Michelle S Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
| | - Richard F Ambrose
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA, USA. Department of Environmental Health Sciences, University of California, Los Angeles, CA, USA
| | - David B Wake
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA. Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Vance T Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA. Department of Biology, San Francisco State University, San Francisco, CA, USA.
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Catenazzi A, Lehr E, Vredenburg VT. Thermal physiology, disease, and amphibian declines on the eastern slopes of the Andes. Conserv Biol 2014; 28:509-517. [PMID: 24372791 DOI: 10.1111/cobi.12194] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 07/12/2013] [Indexed: 06/03/2023]
Abstract
Rising temperatures, a widespread consequence of climate change, have been implicated in enigmatic amphibian declines from habitats with little apparent human impact. The pathogenic fungus Batrachochytrium dendrobatidis (Bd), now widespread in Neotropical mountains, may act in synergy with climate change causing collapse in thermally stressed hosts. We measured the thermal tolerance of frogs along a wide elevational gradient in the Tropical Andes, where frog populations have collapsed. We used the difference between critical thermal maximum and the temperature a frog experiences in nature as a measure of tolerance to high temperatures. Temperature tolerance increased as elevation increased, suggesting that frogs at higher elevations may be less sensitive to rising temperatures. We tested the alternative pathogen optimal growth hypothesis that prevalence of the pathogen should decrease as temperatures fall outside the optimal range of pathogen growth. Our infection-prevalence data supported the pathogen optimal growth hypothesis because we found that prevalence of Bd increased when host temperatures matched its optimal growth range. These findings suggest that rising temperatures may not be the driver of amphibian declines in the eastern slopes of the Andes. Zoonotic outbreaks of Bd are the most parsimonious hypothesis to explain the collapse of montane amphibian faunas; but our results also reveal that lowland tropical amphibians, despite being shielded from Bd by higher temperatures, are vulnerable to climate-warming stress.
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Affiliation(s)
- Alessandro Catenazzi
- Department of Zoology, Southern Illinois University, Carbondale, IL, 62901, U.S.A..
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Vredenburg VT, Felt SA, Morgan EC, McNally SVG, Wilson S, Green SL. Prevalence of Batrachochytrium dendrobatidis in Xenopus collected in Africa (1871-2000) and in California (2001-2010). PLoS One 2013; 8:e63791. [PMID: 23691097 PMCID: PMC3655066 DOI: 10.1371/journal.pone.0063791] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 04/09/2013] [Indexed: 11/18/2022] Open
Abstract
International trade of the invasive South African clawed frog (Xenopus laevis), a subclinical carrier of the fungal pathogen Batrachochytrium dendrobatis (Bd) has been proposed as a major means of introduction of Bd into naïve, susceptible amphibian populations. The historical presence of Bd in the indigenous African population of Xenopus is well documented. However, there are no reports documenting the presence of Bd in wild Xenopus populations in the US, particularly in California where introduced populations are well-established after intentional or accidental release. In this report, a survey was conducted on 178 archived specimens of 6 species of Xenopus collected in Africa from 1871–2000 and on 23 archived specimens (all wild-caught Xenopus laevis) collected in California, USA between 2001 and 2010. The overall prevalence rate of Bd in the tested Xenopus was 2.8%. The earliest positive specimen was X. borealis collected in Kenya in 1934. The overall prevalence of Bd in the X. laevis collected in California was 13% with 2 positive specimens from 2001 and one positive specimen from 2003. The positive Xenopus (3/23) collected in California were collected in 2001 (2/3) and 2003 (1/3). These data document the presence of Bd-infected wild Xenopus laevis in California. The findings reported here support the prevailing hypothesis that Bd was present as a stable, endemic infection in Xenopus populations in Africa prior to their worldwide distribution likely via international live-amphibian trade.
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Affiliation(s)
- Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, United States of America.
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Voyles J, Vredenburg VT, Tunstall TS, Parker JM, Briggs CJ, Rosenblum EB. Pathophysiology in mountain yellow-legged frogs (Rana muscosa) during a chytridiomycosis outbreak. PLoS One 2012; 7:e35374. [PMID: 22558145 PMCID: PMC3338830 DOI: 10.1371/journal.pone.0035374] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 03/15/2012] [Indexed: 11/18/2022] Open
Abstract
The disease chytridiomycosis is responsible for declines and extirpations of amphibians worldwide. Chytridiomycosis is caused by a fungal pathogen (Batrachochytrium dendrobatidis) that infects amphibian skin. Although we have a basic understanding of the pathophysiology from laboratory experiments, many mechanistic details remain unresolved and it is unknown if disease development is similar in wild amphibian populations. To gain a better understanding of chytridiomycosis pathophysiology in wild amphibian populations, we collected blood biochemistry measurements during an outbreak in mountain yellow-legged frogs (Rana muscosa) in the Sierra Nevada Mountains of California. We found that pathogen load is associated with disruptions in fluid and electrolyte balance, yet is not associated with fluctuations acid-base balance. These findings enhance our knowledge of the pathophysiology of this disease and indicate that disease development is consistent across multiple species and in both laboratory and natural conditions. We recommend integrating an understanding of chytridiomycosis pathophysiology with mitigation practices to improve amphibian conservation.
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Affiliation(s)
- Jamie Voyles
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California United States of America
| | - Vance T. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California United States of America
| | - Tate S. Tunstall
- Department of Integrative Biology, University of California, Berkeley, California United States of America
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California United States of America
| | - John M. Parker
- Animal Care Facility, University of California San Francisco, San Francisco, California, California United States of America
| | - Cheryl J. Briggs
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California United States of America
| | - Erica Bree Rosenblum
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California United States of America
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Reeder NMM, Pessier AP, Vredenburg VT. A reservoir species for the emerging Amphibian pathogen Batrachochytrium dendrobatidis thrives in a landscape decimated by disease. PLoS One 2012; 7:e33567. [PMID: 22428071 PMCID: PMC3299797 DOI: 10.1371/journal.pone.0033567] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 02/14/2012] [Indexed: 11/18/2022] Open
Abstract
Chytridiomycosis, a disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is driving amphibian declines and extinctions in protected areas globally. The introduction of invasive reservoir species has been implicated in the spread of Bd but does not explain the appearance of the pathogen in remote protected areas. In the high elevation (>1500 m) Sierra Nevada of California, the native Pacific chorus frog, Pseudacris regilla, appears unaffected by chytridiomycosis while sympatric species experience catastrophic declines. We investigated whether P. regilla is a reservoir of Bd by comparing habitat occupancy before and after a major Bd outbreak and measuring infection in P. regilla in the field, monitoring susceptibility of P. regilla to Bd in the laboratory, examining tissues with histology to determine patterns of infection, and using an innovative soak technique to determine individual output of Bd zoospores in water. Pseudacris regilla persists at 100% of sites where a sympatric species has been extirpated from 72% in synchrony with a wave of Bd. In the laboratory, P. regilla carried loads of Bd as much as an order of magnitude higher than loads found lethal to sympatric species. Histology shows heavy Bd infection in patchy areas next to normal skin, a possible mechanism for tolerance. The soak technique was 77.8% effective at detecting Bd in water and showed an average output of 68 zoospores per minute per individual. The results of this study suggest P. regilla should act as a Bd reservoir and provide evidence of a tolerance mechanism in a reservoir species.
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Affiliation(s)
- Natalie M M Reeder
- Department of Biology, San Francisco State University, San Francisco, California, United States of America.
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Woodhams DC, Geiger CC, Reinert LK, Rollins-Smith LA, Lam B, Harris RN, Briggs CJ, Vredenburg VT, Voyles J. Treatment of amphibians infected with chytrid fungus: learning from failed trials with itraconazole, antimicrobial peptides, bacteria, and heat therapy. Dis Aquat Organ 2012; 98:11-25. [PMID: 22422126 DOI: 10.3354/dao02429] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Amphibian conservation goals depend on effective disease-treatment protocols. Desirable protocols are species, life stage, and context specific, but currently few treatment options exist for amphibians infected with the chytrid fungus Batrachochytrium dendrobatidis (Bd). Treatment options, at present, include antifungal drugs and heat therapy, but risks of toxicity and side-effects make these options untenable in some cases. Here, we report on the comparison of several novel treatments with a more generally accepted antifungal treatment in experimental scientific trials to treat Bd-infected frogs including Alytes obstetricans tadpoles and metamorphs, Bufo bufo and Limnodynastes peronii metamorphs, and Lithobates pipiens and Rana muscosa adults. The experimental treatments included commercial antifungal products (itraconazole, mandipropamid, steriplantN, and PIP Pond Plus), antimicrobial skin peptides from the Bd-resistant Pelophylax esculentus, microbial treatments (Pedobacter cryoconitis), and heat therapy (35°C for 24 h). None of the new experimental treatments were considered successful in terms of improving survival; however, these results may advance future research by indicating the limits and potential of the various protocols. Caution in the use of itraconazole is warranted because of observed toxicity in metamorphic and adult frogs, even at low concentrations. Results suggest that rather than focusing on a single cure-all, diverse lines of research may provide multiple options for treating Bd infection in amphibians. Learning from 'failed treatments' is essential for the timely achievement of conservation goals and one of the primary aims for a publicly accessible treatment database under development.
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Affiliation(s)
- Douglas C Woodhams
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
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Swei A, Rowley JJL, Rödder D, Diesmos MLL, Diesmos AC, Briggs CJ, Brown R, Cao TT, Cheng TL, Chong RA, Han B, Hero JM, Hoang HD, Kusrini MD, Le DTT, McGuire JA, Meegaskumbura M, Min MS, Mulcahy DG, Neang T, Phimmachak S, Rao DQ, Reeder NM, Schoville SD, Sivongxay N, Srei N, Stöck M, Stuart BL, Torres LS, Tran DTA, Tunstall TS, Vieites D, Vredenburg VT. Is chytridiomycosis an emerging infectious disease in Asia? PLoS One 2011; 6:e23179. [PMID: 21887238 PMCID: PMC3156717 DOI: 10.1371/journal.pone.0023179] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 07/07/2011] [Indexed: 12/02/2022] Open
Abstract
The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused dramatic amphibian population declines and extinctions in Australia, Central and North America, and Europe. Bd is associated with >200 species extinctions of amphibians, but not all species that become infected are susceptible to the disease. Specifically, Bd has rapidly emerged in some areas of the world, such as in Australia, USA, and throughout Central and South America, causing population and species collapse. The mechanism behind the rapid global emergence of the disease is poorly understood, in part due to an incomplete picture of the global distribution of Bd. At present, there is a considerable amount of geographic bias in survey effort for Bd, with Asia being the most neglected continent. To date, Bd surveys have been published for few Asian countries, and infected amphibians have been reported only from Indonesia, South Korea, China and Japan. Thus far, there have been no substantiated reports of enigmatic or suspected disease-caused population declines of the kind that has been attributed to Bd in other areas. In order to gain a more detailed picture of the distribution of Bd in Asia, we undertook a widespread, opportunistic survey of over 3,000 amphibians for Bd throughout Asia and adjoining Papua New Guinea. Survey sites spanned 15 countries, approximately 36° latitude, 111° longitude, and over 2000 m in elevation. Bd prevalence was very low throughout our survey area (2.35% overall) and infected animals were not clumped as would be expected in epizootic events. This suggests that Bd is either newly emerging in Asia, endemic at low prevalence, or that some other ecological factor is preventing Bd from fully invading Asian amphibians. The current observed pattern in Asia differs from that in many other parts of the world.
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Affiliation(s)
- Andrea Swei
- Cary Institute of Ecosystem Studies, Millbrook, New York, United States of America.
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Catenazzi A, Lehr E, Rodriguez LO, Vredenburg VT. Batrachochytrium dendrobatidis and the collapse of anuran species richness and abundance in the Upper Manu National Park, Southeastern Peru. Conserv Biol 2011; 25:382-391. [PMID: 21054530 DOI: 10.1111/j.1523-1739.2010.01604.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Amphibians are declining worldwide, but these declines have been particularly dramatic in tropical mountains, where high endemism and vulnerability to an introduced fungal pathogen, Batrachochytrium dendrobatidis (Bd), is associated with amphibian extinctions. We surveyed frogs in the Peruvian Andes in montane forests along a steep elevational gradient (1200-3700 m). We used visual encounter surveys to sample stream-dwelling and arboreal species and leaf-litter plots to sample terrestrial-breeding species. We compared species richness and abundance among the wet seasons of 1999, 2008, and 2009. Despite similar sampling effort among years, the number of species (46 in 1999) declined by 47% between 1999 and 2008 and by 38% between 1999 and 2009. When we combined the number of species we found in 2008 and 2009, the decline from 1999 was 36%. Declines of stream-dwelling and arboreal species (a reduction in species richness of 55%) were much greater than declines of terrestrial-breeding species (reduction of 20% in 2008 and 24% in 2009). Similarly, abundances of stream-dwelling and arboreal frogs were lower in the combined 2008-2009 period than in 1999, whereas densities of frogs in leaf-litter plots did not differ among survey years. These declines may be associated with the infection of frogs with Bd. B. dendrobatidis prevalence correlated significantly with the proportion of species that were absent from the 2008 and 2009 surveys along the elevational gradient. Our results suggest Bd may have arrived at the site between 1999 and 2007, which is consistent with the hypothesis that this pathogen is spreading in epidemic waves along the Andean cordilleras. Our results also indicate a rapid decline of frog species richness and abundance in our study area, a national park that contains many endemic amphibian species and is high in amphibian species richness.
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Affiliation(s)
- Alessandro Catenazzi
- Department of Integrative Biology, University of California at Berkeley, Berkeley, CA 94720,USA.
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Catenazzi A, Vredenburg VT, Lehr E. Batrachochytrium dendrobatidis in the live frog trade of Telmatobius (Anura: Ceratophryidae) in the tropical Andes. Dis Aquat Organ 2010; 92:187-191. [PMID: 21268980 DOI: 10.3354/dao02250] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Species of frogs in the genus Telmatobius are traded and sold for human consumption in the Andes and in coastal cities of Peru and Bolivia. These frogs are harvested from wild populations. We report high prevalence of infection by the pathogenic fungus Batrachochytrium dendrobatidis in live frogs purchased at the main market in Cusco, Peru, from January 2008 to January 2010. We suggest that the transport of native anurans through the live frog trade could facilitate the spread of this fungus among Andean frogs. The tropical Andes are the most important biodiversity hotspot for amphibians. Because many neotropical taxa are known to be susceptible to chytridiomycosis, the presence of a large reservoir of infection in the frog trade poses a significant threat to amphibian conservation.
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Affiliation(s)
- Alessandro Catenazzi
- Department of Integrative Biology, University of California at Berkeley, 3060 Valley Life Sciences, Berkeley, California 94707, USA.
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