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Parrish K, Kirkland P, Horwood P, Chessman B, Ruming S, McGilvray G, Rose K, Hall J, Skerratt L. Delving into the Aftermath of a Disease-Associated Near-Extinction Event: A Five-Year Study of a Serpentovirus (Nidovirus) in a Critically Endangered Turtle Population. Viruses 2024; 16:653. [PMID: 38675993 PMCID: PMC11055124 DOI: 10.3390/v16040653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/17/2024] [Accepted: 04/20/2024] [Indexed: 04/28/2024] Open
Abstract
Bellinger River virus (BRV) is a serpentovirus (nidovirus) that was likely responsible for the catastrophic mortality of the Australian freshwater turtle Myuchelys georgesi in February 2015. From November 2015 to November 2020, swabs were collected from turtles during repeated river surveys to estimate the prevalence of BRV RNA, identify risk factors associated with BRV infection, and refine sample collection. BRV RNA prevalence at first capture was significantly higher in M. georgesi (10.8%) than in a coexisting turtle, Emydura macquarii (1.0%). For M. georgesi, various risk factors were identified depending on the analysis method, but a positive BRV result was consistently associated with a larger body size. All turtles were asymptomatic when sampled and conjunctival swabs were inferred to be optimal for ongoing monitoring. Although the absence of disease and recent BRV detections suggests a reduced ongoing threat, the potential for the virus to persist in an endemic focus or resurge in cyclical epidemics cannot be excluded. Therefore, BRV is an ongoing potential threat to the conservation of M. georgesi, and strict adherence to biosecurity principles is essential to minimise the risk of reintroduction or spread of BRV or other pathogens.
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Affiliation(s)
- Kate Parrish
- Virology Laboratory, Elizabeth Macarthur Agriculture Institute, Department of Primary Industries, Menangle, NSW 2568, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4810, Australia
| | - Peter Kirkland
- Virology Laboratory, Elizabeth Macarthur Agriculture Institute, Department of Primary Industries, Menangle, NSW 2568, Australia
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4810, Australia
| | - Paul Horwood
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4810, Australia
| | | | - Shane Ruming
- Biodiversity Conservation and Science, New South Wales Department of Climate Change, Energy, the Environment and Water, Coffs Harbour, NSW 2450, Australia
| | - Gerry McGilvray
- Biodiversity Conservation and Science, New South Wales Department of Climate Change, Energy, the Environment and Water, Coffs Harbour, NSW 2450, Australia
| | - Karrie Rose
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Mosman, NSW 2088, Australia
| | - Jane Hall
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Mosman, NSW 2088, Australia
| | - Lee Skerratt
- Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, VIC 3030, Australia
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2
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Hartmann AM, McGrath-Blaser SE, Colón-Piñeiro Z, Longo AV. Ontogeny drives shifts in skin bacterial communities in facultatively paedomorphic salamanders. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001399. [PMID: 37815535 PMCID: PMC10634365 DOI: 10.1099/mic.0.001399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 10/02/2023] [Indexed: 10/11/2023]
Abstract
Microbiomes are major determinants of host growth, development and survival. In amphibians, host-associated bacteria in the skin can inhibit pathogen infection, but many processes can influence the structure and composition of the community. Here we quantified the shifts in skin-associated bacteria across developmental stages in the striped newt (Notophthalmus perstriatus), a threatened salamander species with a complex life history and vulnerable to infection by the amphibian chytrid fungus Batrachochytrium dendrobatidis and ranavirus. Our analyses show that pre-metamorphic larval and paedomorphic stages share similar bacterial compositions, and that the changes in the microbiome coincided with physiological restructuring during metamorphosis. Newts undergoing metamorphosis exhibited microbiome compositions that were intermediate between paedomorphic and post-metamorphic stages, further supporting the idea that metamorphosis is a major driver of host-associated microbes in amphibians. We did not find support for infection-related disruption of the microbiome, though infection replicates were small for each respective life stage.
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Affiliation(s)
- Arik M. Hartmann
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | | | | | - Ana V. Longo
- Department of Biology, University of Florida, Gainesville, Florida, USA
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3
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Nolan N, Hayward MW, Klop-Toker K, Mahony M, Lemckert F, Callen A. Complex Organisms Must Deal with Complex Threats: How Does Amphibian Conservation Deal with Biphasic Life Cycles? Animals (Basel) 2023; 13:ani13101634. [PMID: 37238064 DOI: 10.3390/ani13101634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/08/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
The unprecedented rate of global amphibian decline is attributed to The Anthropocene, with human actions triggering the Sixth Mass Extinction Event. Amphibians have suffered some of the most extreme declines, and their lack of response to conservation actions may reflect challenges faced by taxa that exhibit biphasic life histories. There is an urgent need to ensure that conservation measures are cost-effective and yield positive outcomes. Many conservation actions have failed to meet their intended goals of bolstering populations to ensure the persistence of species into the future. We suggest that past conservation efforts have not considered how different threats influence multiple life stages of amphibians, potentially leading to suboptimal outcomes for their conservation. Our review highlights the multitude of threats amphibians face at each life stage and the conservation actions used to mitigate these threats. We also draw attention to the paucity of studies that have employed multiple actions across more than one life stage. Conservation programs for biphasic amphibians, and the research that guides them, lack a multi-pronged approach to deal with multiple threats across the lifecycle. Conservation management programs must recognise the changing threat landscape for biphasic amphibians to reduce their notoriety as the most threatened vertebrate taxa globally.
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Affiliation(s)
- Nadine Nolan
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Matthew W Hayward
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Kaya Klop-Toker
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Michael Mahony
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Frank Lemckert
- Eco Logical Australia Pty Ltd., Perth, WA 6000, Australia
| | - Alex Callen
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
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4
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Wu NC. Pathogen load predicts host functional disruption: A meta‐analysis of an amphibian fungal panzootic. Funct Ecol 2023. [DOI: 10.1111/1365-2435.14245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Nicholas C. Wu
- Hawkesbury Institute for the Environment Western Sydney University Richmond New South Wales Australia
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5
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Landler L. Orientation and emigration of larval and juvenile amphibians: selected topics and hypotheses. AMPHIBIA-REPTILIA 2022; 43:1-11. [PMID: 35440836 PMCID: PMC7612629 DOI: 10.1163/15685381-bja10081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Most amphibians have a complex life cycle with an aquatic larval and an adult (semi-) terrestrial stage. However, studies concerning spatial behaviour and orientation mainly focus on either the aquatic larvae or the adult animals on land. Consequently, behavioural changes that happen during metamorphosis and the consequences for emigration and population distribution are less understood. This paper aims to summarize the knowledge concerning specific topics of early amphibian life history stages and proposes several testable hypotheses within the following fields of research: larval and juvenile orientation, influences of environmental and genetic factors on juvenile emigration, their habitat choice later in life as well as population biology. I argue that studying larval and juvenile amphibian spatial behaviour is an understudied field of research, however, could considerably improve our understanding of amphibian ecology.
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Affiliation(s)
- Lukas Landler
- University of Natural Resources and Life Sciences (BOKU), Institute of Zoology, Gregor-Mendel-Straße 33, 1180 Vienna, Austria
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6
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Westrick SE, Laslo M, Fischer E. Natural History of Model Organisms: The big potential of the small frog Eleutherodactylus coqui. eLife 2022; 11:73401. [PMID: 35029143 PMCID: PMC8824473 DOI: 10.7554/elife.73401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 01/13/2022] [Indexed: 12/02/2022] Open
Abstract
The Puerto Rican coquí frog Eleutherodactylus coqui is both a cultural icon and a species with an unusual natural history that has attracted attention from researchers in a number of different fields within biology. Unlike most frogs, the coquí frog skips the tadpole stage, which makes it of interest to developmental biologists. The frog is best known in Puerto Rico for its notoriously loud mating call, which has allowed researchers to study aspects of social behavior such as vocal communication and courtship, while the ability of coquí to colonize new habitats has been used to explore the biology of invasive species. This article reviews existing studies on the natural history of E. coqui and discusses opportunities for future research.
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Affiliation(s)
- Sarah E Westrick
- Department of Evolution, Ecology, and Behavior, University of Illinois Urbana-Champaign, Urbana, United States
| | - Mara Laslo
- Curriculum Fellow Program, Harvard University, Cambridge, United States
| | - Eva Fischer
- Department of Evolution, Ecology, and Behavior, University of Illinois Urbana-Champaign, Urbana and Champaign, United States
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7
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Campos‐Cerqueira M, Aide TM. Impacts of a drought and hurricane on tropical bird and frog distributions. Ecosphere 2021. [DOI: 10.1002/ecs2.3352] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
| | - T. Mitchell Aide
- Rainforest Connection San Francisco California94102USA
- Department of Biology University of Puerto Rico‐Rio Piedras San Juan Puerto Rico00931‐3360USA
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8
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Longo AV, Rodríguez‐Gómez CA, Zegarra JP, Monzón O, Claudio‐Hernández HJ, Joglar RL, Zamudio KR, Burrowes PA, López‐Torres AL. Tick parasitism as a cost of sexual selection and male parental care in a Neotropical frog. Ecosphere 2020. [DOI: 10.1002/ecs2.3010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Ana V. Longo
- Department of Biology University of Florida P.O. Box 118525 Gainesville Florida 32605 USA
| | - Carlos A. Rodríguez‐Gómez
- Proyecto Coquí 120 La Sierra #132 San Juan 00926 Puerto Rico
- Para La Naturaleza P.O. Box 9023554 San Juan 00902‐3554 Puerto Rico
| | - Jan P. Zegarra
- Caribbean Ecological Services Field Office U.S. Fish and Wildlife Service P.O. Box 491 Boquerón 00622 Puerto Rico
| | - Omar Monzón
- Para La Naturaleza P.O. Box 9023554 San Juan 00902‐3554 Puerto Rico
| | | | - Rafael L. Joglar
- Proyecto Coquí 120 La Sierra #132 San Juan 00926 Puerto Rico
- Department of Biology University of Puerto Rico P.O. Box 23360 San Juan 00931‐3360 Puerto Rico
| | - Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology Cornell University E145 Corson Hall Ithaca New York 14853 USA
| | - Patricia A. Burrowes
- Department of Biology University of Puerto Rico P.O. Box 23360 San Juan 00931‐3360 Puerto Rico
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9
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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: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [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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10
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Ribeiro LP, Carvalho T, Becker CG, Jenkinson TS, Leite DDS, James TY, Greenspan SE, Toledo LF. Bullfrog farms release virulent zoospores of the frog-killing fungus into the natural environment. Sci Rep 2019; 9:13422. [PMID: 31530868 PMCID: PMC6748994 DOI: 10.1038/s41598-019-49674-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 08/15/2019] [Indexed: 11/09/2022] Open
Abstract
Bullfrog farming and trade practices are well-established, globally distributed, and economically valuable, but pose risks for biodiversity conservation. Besides their negative impacts on native amphibian populations as an invasive species, bullfrogs play a key role in spreading the frog-killing fungus Batrachochytrium dendrobatidis (Bd) in the natural environment. Bullfrogs are tolerant to Bd, meaning that they can carry high infection loads without developing chytridiomycosis. To test the potential of bullfrog farms as reservoirs for diverse and virulent chytrid genotypes, we quantified Bd presence, prevalence and infection loads across approximately 1,500 farmed bullfrogs and in the water that is released from farms into the environment. We also described Bd genotypic diversity within frog farms by isolating Bd from dozens of infected tadpoles. We observed individuals infected with Bd in all sampled farms, with high prevalence (reaching 100%) and high infection loads (average 71,029 zoospore genomic equivalents). Average outflow water volume from farms was high (60,000 L/day), with Bd zoospore concentration reaching approximately 50 million zoospores/L. Because virulent pathogen strains are often selected when growing in tolerant hosts, we experimentally tested whether Bd genotypes isolated from bullfrogs are more virulent in native anuran hosts compared to genotypes isolated from native host species. We genotyped 36 Bd isolates from two genetic lineages and found that Bd genotypes cultured from bullfrogs showed similar virulence in native toads when compared to genotypes isolated from native hosts. Our results indicate that bullfrog farms can harbor high Bd genotypic diversity and virulence and may be contributing to the spread of virulent genotypes in the natural environment. We highlight the urgent need to implement Bd monitoring and mitigation strategies in bullfrog farms to aid in the conservation of native amphibians.
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Affiliation(s)
- Luisa P Ribeiro
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CEP 13083-862, Campinas, São Paulo, Brazil.
| | - Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CEP 13083-862, Campinas, São Paulo, Brazil
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama, 35487, USA
| | - Thomas S Jenkinson
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Domingos da Silva Leite
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CEP 13083-862, Campinas, Sao Paulo, Brazil
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Sasha E Greenspan
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama, 35487, USA
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CEP 13083-862, Campinas, São Paulo, Brazil
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11
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Jiménez RR, Alvarado G, Estrella J, Sommer S. Moving Beyond the Host: Unraveling the Skin Microbiome of Endangered Costa Rican Amphibians. Front Microbiol 2019; 10:2060. [PMID: 31572313 PMCID: PMC6751270 DOI: 10.3389/fmicb.2019.02060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/21/2019] [Indexed: 01/12/2023] Open
Abstract
Some neotropical amphibians, including a few species in Costa Rica, were presumed to be "extinct" after dramatic population declines in the late 1980s but have been rediscovered in isolated populations. Such populations seem to have evolved a resistance/tolerance to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes a deadly skin disease and is considered one of the main drivers of worldwide amphibian declines. The skin microbiome is an important component of the host's innate immune system and is associated with Bd-resistance. However, the way that the bacterial diversity of the skin microbiome confers protection against Bd in surviving species remains unclear. We studied variation in the skin microbiome and the prevalence of putatively anti-Bd bacterial taxa in four co-habiting species in the highlands of the Juan Castro Blanco National Park in Costa Rica using 16S rRNA amplicon sequencing. Lithobates vibicarius, Craugastor escoces, and Isthmohyla rivularis have recently been rediscovered, whereas Isthmohyla pseudopuma has suffered population fluctuations but has never disappeared. To investigate the life stage at which the protective skin microbiome is shaped and when shifts occur in the diversity of putatively anti-Bd bacteria, we studied the skin microbiome of tadpoles, juveniles and adults of L. vibicarius. We show that the skin bacterial composition of sympatric species and hosts with distinct Bd-infection statuses differs at the phyla, family, and genus level. We detected 94 amplicon sequence variants (ASVs) with putative anti-Bd activity pertaining to distinct bacterial taxa, e.g., Pseudomonas spp., Acinetobacter johnsonii, and Stenotrophomonas maltophilia. Bd-uninfected L. vibicarius harbored 79% more putatively anti-Bd ASVs than Bd-infected individuals. Although microbiome composition and structure differed across life stages, the diversity of putative anti-Bd bacteria was similar between pre- and post-metamorphic stages of L. vibicarius. Despite low sample size, our results support the idea that the skin microbiome is dynamic and protects against ongoing Bd presence in endangered species persisting after their presumed extinction. Our study serves as a baseline to understand the microbial patterns in species of high conservation value. Identification of microbial signatures linked to variation in disease susceptibility might, therefore, inform mitigation strategies for combating the global decline of amphibians.
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Affiliation(s)
- Randall R. Jiménez
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Gilbert Alvarado
- Laboratory of Comparative Wildlife Pathology, School of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, Brazil
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Josimar Estrella
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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12
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Bradley PW, Snyder PW, Blaustein AR. Host age alters amphibian susceptibility to Batrachochytrium dendrobatidis, an emerging infectious fungal pathogen. PLoS One 2019; 14:e0222181. [PMID: 31491016 PMCID: PMC6730893 DOI: 10.1371/journal.pone.0222181] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 08/23/2019] [Indexed: 11/18/2022] Open
Abstract
Parasites and pathogens are often aggregated in a minority of susceptible hosts within a population, with a majority of individuals harboring low infection intensities. However, determining the relative importance of host traits to explain this heterogeneity is a challenge. One ecologically important pathogen is Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis and has been associated with many amphibian population declines worldwide. For many hosts, post-metamorphic stages are generally more susceptible than the larval stage. Yet, examination of the effects of Bd infection at different ages within a life stage, has received little attention. This study investigated the hypothesis that recently-post-metamorphic frogs were more sensitive to chytridiomycosis than older frogs, and that sensitivity to Bd infection decreased as frogs aged. We examined this relationship with Pacific treefrogs (Pseudacris regilla) and red legged frogs (Rana aurora). Age had a strong effect on susceptibility to infection, infection intensity, and survival-but not in the directions we had predicted. In both host species, an increase in age was associated with frogs becoming more susceptible to Bd infection, harboring larger infection intensities, and greater risk of mortality. This suggests that the timing of Bd exposure may influence amphibian population dynamics.
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Affiliation(s)
- Paul W. Bradley
- Environmental Sciences Graduate Program, Oregon State University, Corvallis, Oregon, United States of America
- * E-mail:
| | - Paul W. Snyder
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Andrew R. Blaustein
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
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13
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Brannelly LA, Martin G, Llewelyn J, Skerratt LF, Berger L. Age- and size-dependent resistance to chytridiomycosis in the invasive cane toad Rhinella marina. DISEASES OF AQUATIC ORGANISMS 2018; 131:107-120. [PMID: 30460917 DOI: 10.3354/dao03278] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In Australia, the cane toad Rhinella marina and chytrid fungus Batrachochytrium dendrobatidis (Bd) are examples of invasive species that have had dramatic impacts on native fauna. However, little is known about the interaction between Bd and cane toads. We aimed to explore the interaction of these 2 species in 3 parts. First, we collated data from the literature on Bd infection in wild cane toads. Second, we tested the susceptibility of recently metamorphosed cane toads to Bd infection. Finally, we modelled the distribution of the 2 species in Australia to identify where they overlap and, therefore, might interact. Through our data collation, we found that adult cane toads are infrequently infected and do not carry high infection burdens; however, our infection experiment showed that metamorphs are highly susceptible to infection and disease, but resistance appears to increase with increasing toad size. Niche modelling revealed overlapping distributions and the potential for cane toads to be affected by chytridiomycosis in the wild. While Bd can cause mortality in small juveniles in the laboratory, warm microhabitats used by wild toads likely prevent infection, and furthermore, high mortality of juveniles is unlikely to affect the adult populations because they are highly fecund. However, to demonstrate the impact of Bd on wild cane toad populations, targeted field studies are required to assess (1) the overall impact of chytridiomycosis on recruitment especially in cooler areas more favourable for Bd and (2) whether cane toad juveniles can amplify Bd exposure of native amphibian species in these areas.
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Affiliation(s)
- Laura A Brannelly
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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14
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Lister BC, Garcia A. Climate-driven declines in arthropod abundance restructure a rainforest food web. Proc Natl Acad Sci U S A 2018; 115:E10397-E10406. [PMID: 30322922 PMCID: PMC6217376 DOI: 10.1073/pnas.1722477115] [Citation(s) in RCA: 269] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A number of studies indicate that tropical arthropods should be particularly vulnerable to climate warming. If these predictions are realized, climate warming may have a more profound impact on the functioning and diversity of tropical forests than currently anticipated. Although arthropods comprise over two-thirds of terrestrial species, information on their abundance and extinction rates in tropical habitats is severely limited. Here we analyze data on arthropod and insectivore abundances taken between 1976 and 2012 at two midelevation habitats in Puerto Rico's Luquillo rainforest. During this time, mean maximum temperatures have risen by 2.0 °C. Using the same study area and methods employed by Lister in the 1970s, we discovered that the dry weight biomass of arthropods captured in sweep samples had declined 4 to 8 times, and 30 to 60 times in sticky traps. Analysis of long-term data on canopy arthropods and walking sticks taken as part of the Luquillo Long-Term Ecological Research program revealed sustained declines in abundance over two decades, as well as negative regressions of abundance on mean maximum temperatures. We also document parallel decreases in Luquillo's insectivorous lizards, frogs, and birds. While El Niño/Southern Oscillation influences the abundance of forest arthropods, climate warming is the major driver of reductions in arthropod abundance, indirectly precipitating a bottom-up trophic cascade and consequent collapse of the forest food web.
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Affiliation(s)
- Bradford C Lister
- Department of Biological Sciences, Rensselaer Polytechnic University, Troy, NY 12180;
| | - Andres Garcia
- Estación de Biología Chamela, Instituto de Biología, Universidad Nacional Autónoma de México, 47152 Chamela, Jalisco, Mexico
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15
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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 JOURNAL 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] [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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16
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Effects of Emerging Infectious Diseases on Amphibians: A Review of Experimental Studies. DIVERSITY-BASEL 2018. [DOI: 10.3390/d10030081] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Numerous factors are contributing to the loss of biodiversity. These include complex effects of multiple abiotic and biotic stressors that may drive population losses. These losses are especially illustrated by amphibians, whose populations are declining worldwide. The causes of amphibian population declines are multifaceted and context-dependent. One major factor affecting amphibian populations is emerging infectious disease. Several pathogens and their associated diseases are especially significant contributors to amphibian population declines. These include the fungi Batrachochytrium dendrobatidis and B. salamandrivorans, and ranaviruses. In this review, we assess the effects of these three pathogens on amphibian hosts as found through experimental studies. Such studies offer valuable insights to the causal factors underpinning broad patterns reported through observational studies. We summarize key findings from experimental studies in the laboratory, in mesocosms, and from the field. We also summarize experiments that explore the interactive effects of these pathogens with other contributors of amphibian population declines. Though well-designed experimental studies are critical for understanding the impacts of disease, inconsistencies in experimental methodologies limit our ability to form comparisons and conclusions. Studies of the three pathogens we focus on show that host susceptibility varies with such factors as species, host age, life history stage, population and biotic (e.g., presence of competitors, predators) and abiotic conditions (e.g., temperature, presence of contaminants), as well as the strain and dose of the pathogen, to which hosts are exposed. Our findings suggest the importance of implementing standard protocols and reporting for experimental studies of amphibian disease.
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17
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Hybrids of amphibian chytrid show high virulence in native hosts. Sci Rep 2018; 8:9600. [PMID: 29941894 PMCID: PMC6018099 DOI: 10.1038/s41598-018-27828-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/06/2018] [Indexed: 01/05/2023] Open
Abstract
Hybridization of parasites can generate new genotypes with high virulence. The fungal amphibian parasite Batrachochytrium dendrobatidis (Bd) hybridizes in Brazil’s Atlantic Forest, a biodiversity hotspot where amphibian declines have been linked to Bd, but the virulence of hybrid genotypes in native hosts has never been tested. We compared the virulence (measured as host mortality and infection burden) of hybrid Bd genotypes to the parental lineages, the putatively hypovirulent lineage Bd-Brazil and the hypervirulent Global Pandemic Lineage (Bd-GPL), in a panel of native Brazilian hosts. In Brachycephalus ephippium, the hybrid exceeded the virulence (host mortality) of both parents, suggesting that novelty arising from hybridization of Bd is a conservation concern. In Ischnocnema parva, host mortality in the hybrid treatment was intermediate between the parent treatments, suggesting that this species is more vulnerable to the aggressive phenotypes associated with Bd-GPL. Dendropsophus minutus showed low overall mortality, but infection burdens were higher in frogs treated with hybrid and Bd-GPL genotypes than with Bd-Brazil genotypes. Our experiment suggests that Bd hybrids have the potential to increase disease risk in native hosts. Continued surveillance is needed to track potential spread of hybrid genotypes and detect future genomic shifts in this dynamic disease system.
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18
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Russo CJM, Ohmer MEB, Cramp RL, Franklin CE. A pathogenic skin fungus and sloughing exacerbate cutaneous water loss in amphibians. ACTA ACUST UNITED AC 2018; 221:221/9/jeb167445. [PMID: 29752415 DOI: 10.1242/jeb.167445] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 03/13/2018] [Indexed: 11/20/2022]
Abstract
Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus that causes the cutaneous, infectious disease chytridiomycosis and has been implicated in population declines of numerous anuran species worldwide. Proximate cause of death by chytridiomycosis is asystolic cardiac arrest as a consequence of severe disruption to electrolyte balance. Animals heavily infected with Bd also experience a disruption to their skin sloughing regime, indicating that core functions of the skin, such as water retention, may be severely impacted. This study examined how skin sloughing, body size and Bd infection interact to influence water loss rates in five Australian frog species: Litoria caerulea, Limnodynastes peronii, Lechriodus fletcheri, Limnodynastes tasmaniensis and Platyplectrum ornatum Rates of water loss more than doubled during sloughing in L.caerulea During active periods across all species, water loss rates were on average 232% higher in Bd infected frogs than in uninfected frogs. This indicates that dehydration stress may be a significant factor contributing to the morbidity of severely Bd infected anurans, a symptom that is then exacerbated by an increased rate of sloughing. When taking size into account, smaller and/or juvenile anurans may be more at risk from dehydration due to Bd infection, as they lose a greater amount of water and slough more frequently than adults. This may in part explain the higher mortality rates typical for small and juvenile frogs infected with Bd Understanding how Bd affects the core functions of the skin, including rates of water loss, can improve our predictions of disease outcome in amphibians.
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Affiliation(s)
- Catherine J M Russo
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Michel E B Ohmer
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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19
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Wu NC, Cramp RL, Franklin CE. Body size influences energetic and osmoregulatory costs in frogs infected with Batrachochytrium dendrobatidis. Sci Rep 2018; 8:3739. [PMID: 29487313 PMCID: PMC5829222 DOI: 10.1038/s41598-018-22002-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 02/06/2018] [Indexed: 12/18/2022] Open
Abstract
Sloughing maintains the skins integrity and critical functionality in amphibians. Given the behavioural, morphological and osmoregulatory changes that accompany sloughing, this process is likely to be physiologically costly. Chytridiomycosis, a cutaneous disease of amphibians caused by the fungus Batrachochytrium dendrobatidis (Bd), disrupts skin function and increases sloughing rates. Moreover, mortality rates from chytridiomycosis are significantly higher in juveniles and so we hypothesised that smaller individuals maybe more susceptible to chytridiomycosis because of allometric scaling effects on the energetic and osmoregulatory costs of sloughing. We measured in-vivo cutaneous ion loss rates and whole animal metabolic rate (MR) of Green tree frogs, Litoria caerulea, over a range of body sizes both infected and uninfected frogs during sloughing. Infected animals had a greater rate of ion loss and mass-specific MR during non-sloughing periods but there were no additional effects of sloughing on either of these parameters. There were also significant interactions with body size and Bd load indicating that smaller animals with higher Bd loads have greater rates of ion loss and higher energetic demands. Our results shed light on why smaller Bd-infected anurans often exhibit greater physiological disruption than larger individuals.
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Affiliation(s)
- Nicholas C Wu
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, 4072, Australia.
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20
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Cramp RL, Franklin CE. Exploring the link between ultraviolet B radiation and immune function in amphibians: implications for emerging infectious diseases. CONSERVATION PHYSIOLOGY 2018; 6:coy035. [PMID: 29992023 PMCID: PMC6022628 DOI: 10.1093/conphys/coy035] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/27/2018] [Accepted: 06/07/2018] [Indexed: 05/07/2023]
Abstract
Amphibian populations the world over are under threat of extinction, with as many as 40% of assessed species listed as threatened under IUCN Red List criteria (a significantly higher proportion than other vertebrate group). Amongst the key threats to amphibian species is the emergence of novel infectious diseases, which have been implicated in the catastrophic amphibian population declines and extinctions seen in many parts of the world. The recent emergence of these diseases coincides with increased ambient levels of ultraviolet B radiation (UVBR) due to anthropogenic thinning of the Earth's protective ozone layer, raising questions about potential interactions between UVBR exposure and disease in amphibians. While reasonably well documented in other vertebrate groups (particularly mammals), the immunosuppressive capacity of UVBR and the potential for it to influence disease outcomes has been largely overlooked in amphibians. Herein, we review the evidence for UVBR-associated immune system disruption in amphibians and identify a number of direct and indirect pathways through which UVBR may influence immune function and disease susceptibility in amphibians. By exploring the physiological mechanisms through which UVBR may affect host immune function, we demonstrate how ambient UVBR could increase amphibian susceptibility to disease. We conclude by discussing the potential implications of elevated UVBR for inter and intraspecific differences in disease dynamics and discuss how future research in this field may be directed to improve our understanding of the role that UVBR plays in amphibian immune function.
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Affiliation(s)
- Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Goddard Building (8), St Lucia, Queensland, Australia
- Corresponding author: School of Biological Sciences, The University of Queensland, Goddard Building (8), St Lucia, Queensland 4072, Australia.
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Goddard Building (8), St Lucia, Queensland, Australia
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21
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Bower DS, Mengersen K, Alford RA, Schwarzkopf L. Using a Bayesian network to clarify areas requiring research in a host-pathogen system. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2017; 31:1373-1382. [PMID: 28464282 DOI: 10.1111/cobi.12950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 03/24/2017] [Accepted: 04/17/2017] [Indexed: 06/07/2023]
Abstract
Bayesian network analyses can be used to interactively change the strength of effect of variables in a model to explore complex relationships in new ways. In doing so, they allow one to identify influential nodes that are not well studied empirically so that future research can be prioritized. We identified relationships in host and pathogen biology to examine disease-driven declines of amphibians associated with amphibian chytrid fungus (Batrachochytrium dendrobatidis). We constructed a Bayesian network consisting of behavioral, genetic, physiological, and environmental variables that influence disease and used them to predict host population trends. We varied the impacts of specific variables in the model to reveal factors with the most influence on host population trend. The behavior of the nodes (the way in which the variables probabilistically responded to changes in states of the parents, which are the nodes or variables that directly influenced them in the graphical model) was consistent with published results. The frog population had a 49% probability of decline when all states were set at their original values, and this probability increased when body temperatures were cold, the immune system was not suppressing infection, and the ambient environment was conducive to growth of B. dendrobatidis. These findings suggest the construction of our model reflected the complex relationships characteristic of host-pathogen interactions. Changes to climatic variables alone did not strongly influence the probability of population decline, which suggests that climate interacts with other factors such as the capacity of the frog immune system to suppress disease. Changes to the adaptive immune system and disease reservoirs had a large effect on the population trend, but there was little empirical information available for model construction. Our model inputs can be used as a base to examine other systems, and our results show that such analyses are useful tools for reviewing existing literature, identifying links poorly supported by evidence, and understanding complexities in emerging infectious-disease systems.
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Affiliation(s)
- D S Bower
- College of Science and Engineering, James Cook University, 1 James Cook Drive, Douglas, QLD, 4811, Australia
| | - K Mengersen
- Faculty of Science and Engineering, Mathematical Sciences, Statistical Science, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - R A Alford
- College of Science and Engineering, James Cook University, 1 James Cook Drive, Douglas, QLD, 4811, Australia
| | - L Schwarzkopf
- College of Science and Engineering, James Cook University, 1 James Cook Drive, Douglas, QLD, 4811, Australia
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22
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Mikó Z, Ujszegi J, Hettyey A. Age-dependent changes in sensitivity to a pesticide in tadpoles of the common toad (Bufo bufo). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 187:48-54. [PMID: 28365461 DOI: 10.1016/j.aquatox.2017.03.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/17/2017] [Accepted: 03/19/2017] [Indexed: 06/07/2023]
Abstract
The worldwide en masse application of pesticides and the frequently reported malign effects on several non-target organisms underpin the importance of ecotoxicological research on these anthropogenic pollutants. Previous studies showed that sensitivity to herbicides can vary widely depending on additional stress factors, on the species and even on the population investigated. However, there is little information about how sensitivity changes during ontogeny, and how the duration of exposure is linked to the magnitude of malign effects, even though this knowledge would be important for the interpretation of toxicity test results and for formulating recommendations regarding the timing of pesticide application. We exposed tadpoles of the common toad (Bufo bufo) to three concentrations (0, 2 and 4mg a.e./L) of a glyphosate-based herbicide during the 1st, 2nd, 3rd, 4th, or 5th period of larval development or during the entire experiment, and measured survival, time until metamorphosis and body mass at metamorphosis to estimate fitness-consequences. Younger tadpoles were more sensitive to the herbicide in all measured traits than older ones, and this age-dependence was especially pronounced at the high herbicide concentration. Furthermore, tadpoles exposed to the herbicide during the entire experiment developed slower than tadpoles exposed only early on, but we did not observe a similar effect either on body mass or survival. The observed age-dependence of sensitivity to herbicides draws attention to the fact that results of toxicity tests obtained for one age-class are not necessarily generalizable across ontogeny. Also, the age of test animals has to be considered when planning ecotoxicological studies and interpreting their results. Finally, taking into account the temporal breeding habits of local amphibians when planning pesticide application would be highly favourable: if tadpoles would not get exposed to the herbicide during their most sensitive early development, they would sustain less anthropogenic damage from our efforts of controlling weeds.
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Affiliation(s)
- Zsanett Mikó
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest 1022, Hungary.
| | - János Ujszegi
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest 1022, Hungary; Department of Systematic Zoology and Ecology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest 1117, Hungary
| | - Attila Hettyey
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest 1022, Hungary
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23
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Burrowes PA, Martes MC, Torres-Ríos M, Longo AV. Arboreality predicts Batrachochytrium dendrobatidis infection level in tropical direct-developing frogs. J NAT HIST 2017. [DOI: 10.1080/00222933.2017.1297504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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24
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Gervasi SS, Stephens PR, Hua J, Searle CL, Xie GY, Urbina J, Olson DH, Bancroft BA, Weis V, Hammond JI, Relyea RA, Blaustein AR. Linking Ecology and Epidemiology to Understand Predictors of Multi-Host Responses to an Emerging Pathogen, the Amphibian Chytrid Fungus. PLoS One 2017; 12:e0167882. [PMID: 28095428 PMCID: PMC5240985 DOI: 10.1371/journal.pone.0167882] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 11/22/2016] [Indexed: 12/12/2022] Open
Abstract
Variation in host responses to pathogens can have cascading effects on populations and communities when some individuals or groups of individuals display disproportionate vulnerability to infection or differ in their competence to transmit infection. The fungal pathogen, Batrachochytrium dendrobatidis (Bd) has been detected in almost 700 different amphibian species and is implicated in numerous global amphibian population declines. Identifying key hosts in the amphibian-Bd system–those who are at greatest risk or who pose the greatest risk for others–is challenging due in part to many extrinsic environmental factors driving spatiotemporal Bd distribution and context-dependent host responses to Bd in the wild. One way to improve predictive risk models and generate testable mechanistic hypotheses about vulnerability is to complement what we know about the spatial epidemiology of Bd with data collected through comparative experimental studies. We used standardized pathogen challenges to quantify amphibian survival and infection trajectories across 20 post-metamorphic North American species raised from eggs. We then incorporated trait-based models to investigate the predictive power of phylogenetic history, habitat use, and ecological and life history traits in explaining responses to Bd. True frogs (Ranidae) displayed the lowest infection intensities, whereas toads (Bufonidae) generally displayed the greatest levels of mortality after Bd exposure. Affiliation with ephemeral aquatic habitat and breadth of habitat use were strong predictors of vulnerability to and intensity of infection and several other traits including body size, lifespan, age at sexual maturity, and geographic range also appeared in top models explaining host responses to Bd. Several of the species examined are highly understudied with respect to Bd such that this study represents the first experimental susceptibility data. Combining insights gained from experimental studies with observations of landscape-level disease prevalence may help explain current and predict future pathogen dynamics in the Bd system.
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Affiliation(s)
- Stephanie S. Gervasi
- Monell Chemical Senses Center, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| | - Patrick R. Stephens
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
| | - Jessica Hua
- Biological Sciences Department, Binghamton University, Binghamton, New York, United States of America
| | - Catherine L. Searle
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Gisselle Yang Xie
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Jenny Urbina
- Environmental Sciences Graduate Program, Oregon State University, Corvallis, Oregon, United States of America
| | - Deanna H. Olson
- United States Forest Service, Pacific Northwest Research Station, Corvallis, Oregon, United States of America
| | - Betsy A. Bancroft
- Biology Department, Gonzaga University, Spokane, Washington, United States of America
| | - Virginia Weis
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - John I. Hammond
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Rick A. Relyea
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, United States of America
| | - Andrew R. Blaustein
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
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25
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DiRenzo GV, Che-Castaldo C, Rugenski A, Brenes R, Whiles MR, Pringle CM, Kilham SS, Lips KR. Disassembly of a tadpole community by a multi-host fungal pathogen with limited evidence of recovery. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:309-320. [PMID: 28052493 DOI: 10.1002/eap.1443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 07/28/2016] [Accepted: 08/24/2016] [Indexed: 06/06/2023]
Abstract
Emerging infectious diseases can cause host community disassembly, but the mechanisms driving the order of species declines and extirpations following a disease outbreak are unclear. We documented the community disassembly of a Neotropical tadpole community during a chytridiomycosis outbreak, triggered by the generalist fungal pathogen, Batrachochytrium dendrobatidis (Bd). Within the first 11 months of Bd arrival, tadpole density and occupancy rapidly declined. Species rarity, in terms of tadpole occupancy and adult relative abundance, did not predict the odds of tadpole occupancy declines. But species losses were taxonomically selective, with glassfrogs (Family: Centrolenidae) disappearing the fastest and tree frogs (Family: Hylidae) and dart-poison frogs (Family: Dendrobatidae) remaining the longest. We detected biotic homogenization of tadpole communities, with post-decline communities resembling one another more strongly than pre-decline communities. The entire tadpole community was extirpated within 22 months following Bd arrival, and we found limited signs of recovery within 10 years post-outbreak. Because of imperfect species detection inherent to sampling species-rich tropical communities and the difficulty of devising a single study design protocol to sample physically complex tropical habitats, we used simulations to provide recommendations for future surveys to adequately sample diverse Neotropical communities. Our unique data set on tadpole community composition before and after Bd arrival is a valuable baseline for assessing amphibian recovery. Our results are of direct relevance to conservation managers and community ecologists interested in understanding the timing, magnitude, and consequences of disease outbreaks as emerging infectious diseases spread globally.
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Affiliation(s)
- Graziella V DiRenzo
- Department of Biology, University of Maryland, College Park, Maryland, 20744, USA
| | | | - Amanda Rugenski
- School of Life Sciences, Arizona State University, Tempe, Arizona, 85281, USA
| | - Roberto Brenes
- Department of Biology, Carroll University, Waukesha, Wisconsin, 53186, USA
| | - Matt R Whiles
- Department of Zoology and Center for Ecology, Southern Illinois University, Carbondale, Illinois, 62901, USA
| | | | - Susan S Kilham
- Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, Pennsylvania, 19104, USA
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, Maryland, 20744, USA
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26
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Terrestrial Growth in Northern Leopard Frogs Reared in the Presence or Absence of Predators and Exposed to the Amphibian Chytrid Fungus at Metamorphosis. J HERPETOL 2016. [DOI: 10.1670/15-102] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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Maguire C, DiRenzo GV, Tunstall TS, Muletz CR, Zamudio KR, Lips KR. Dead or alive? Viability of chytrid zoospores shed from live amphibian hosts. DISEASES OF AQUATIC ORGANISMS 2016; 119:179-187. [PMID: 27225201 DOI: 10.3354/dao02991] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Pathogens vary in virulence and rates of transmission because of many differences in the host, the pathogen, and their environment. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), affects amphibian hosts differently, causing extinction and population declines in some species but having limited effects on others. Phenotypic differences in zoospore production rates among Bd lineages likely contribute to some of the variation observed among host responses, although no studies have quantified the viability of zoospores shed from live animals. We compared host survivorship, infection intensity, shedding rates, and zoospore viability between 2 species of endangered tropical frogs, Hylomantis lemur and Atelopus zeteki, when exposed to a highly virulent lineage of Bd (JEL 423). We applied a dye to zoospores 30 to 60 min following animal soaks, to estimate shedding rate and proportion of live zoospores shed by different species. The average infection intensity for A. zeteki was nearly 17 times higher (31,455 ± 10,103 zoospore genomic equivalents [ZGEs]) than that of H. lemur (1832 ± 1086 ZGEs), and A. zeteki died earlier than H. lemur. The proportion of viable zoospores was ~80% in both species throughout the experiment, although A. zeteki produced many more zoospores, suggesting it may play a disproportionate role in spreading disease in communities where it occurs, because the large number of viable zoospores they produce might increase infection in other species where they are reintroduced.
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Affiliation(s)
- Chelsea Maguire
- Department of Integrative Biology, University of Illinois, Urbana-Champaign, IL 61820, USA
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Stockwell MP, Garnham JI, Bower DS, Clulow J, Mahony MJ. Low disease-causing threshold in a frog species susceptible to chytridiomycosis. FEMS Microbiol Lett 2016; 363:fnw111. [PMID: 27190153 DOI: 10.1093/femsle/fnw111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2016] [Indexed: 01/05/2023] Open
Abstract
A simple diagnosis of the presence or absence of an infection is an uninformative metric when individuals differ considerably in their tolerance to different infection loads or resistance to rates of disease progression. Models that incorporate the relationship between the progression of the infection with the potential alternate outcomes provide a far more powerful predictive tool than diagnosis alone. The global decline of amphibians has been amplified by Batrachochytrium dendrobatidis, a pathogen that can cause the fatal disease chytridiomycosis. We measured the infection load and observed signs of disease in Litoria aurea Receiver operating characteristic curves were used to quantify the dissimilarity between the infection loads of L. aurea that showed signs associated with chytridiomycosis and those that did not. Litoria aurea had a 78% probability of developing chytridiomycosis past a threshold of 68 zoospore equivalents (ZE) per swab and chytridiomycosis occurred within a variable range of 0.5-490 ZE. Studies should incorporate a species-specific threshold as a predictor of chytridiomycosis, rather than a binary diagnosis. Measures of susceptibility to chytridiomycosis must account not only for the ability of B. dendrobatidis to increase its abundance on the skin of amphibians but also to determine how each species tolerates these infection loads.
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Affiliation(s)
- Michelle P Stockwell
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - James I Garnham
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - Deborah S Bower
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - John Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - Michael J Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
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Susceptibility to disease varies with ontogeny and immunocompetence in a threatened amphibian. Oecologia 2016; 181:997-1009. [DOI: 10.1007/s00442-016-3607-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
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Woodhams DC, Bell SC, Bigler L, Caprioli RM, Chaurand P, Lam BA, Reinert LK, Stalder U, Vazquez VM, Schliep K, Hertz A, Rollins-Smith LA. Life history linked to immune investment in developing amphibians. CONSERVATION PHYSIOLOGY 2016; 4:cow025. [PMID: 27928507 PMCID: PMC5001151 DOI: 10.1093/conphys/cow025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 05/09/2016] [Accepted: 05/14/2016] [Indexed: 05/03/2023]
Abstract
The broad diversity of amphibian developmental strategies has been shaped, in part, by pathogen pressure, yet trade-offs between the rate of larval development and immune investment remain poorly understood. The expression of antimicrobial peptides (AMPs) in skin secretions is a crucial defense against emerging amphibian pathogens and can also indirectly affect host defense by influencing the composition of skin microbiota. We examined the constitutive or induced expression of AMPs in 17 species at multiple life-history stages. We found that AMP defenses in tadpoles of species with short larval periods (fast pace of life) were reduced in comparison with species that overwinter as tadpoles and grow to a large size. A complete set of defensive peptides emerged soon after metamorphosis. These findings support the hypothesis that species with a slow pace of life invest energy in AMP production to resist potential pathogens encountered during the long larval period, whereas species with a fast pace of life trade this investment in defense for more rapid growth and development.
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Affiliation(s)
- Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
- Corresponding author: Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA. Tel: +1 617 287 6679.
| | - Sara C Bell
- College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Laurent Bigler
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - 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, Canada H3T 1J4
| | - Brianna A Lam
- Department of Biology, James Madison University, MSC 7801, Harrisonburg, VA 22807, USA
| | - Laura K Reinert
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
| | - Urs Stalder
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | | | - Klaus Schliep
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
| | - Andreas Hertz
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
| | - Louise A Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
- Department of Biological Science, Vanderbilt University, Nashville, TN 37235-1634, USA
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
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Longo AV, Savage AE, Hewson I, Zamudio KR. Seasonal and ontogenetic variation of skin microbial communities and relationships to natural disease dynamics in declining amphibians. ROYAL SOCIETY OPEN SCIENCE 2015; 2:140377. [PMID: 26587253 PMCID: PMC4632566 DOI: 10.1098/rsos.140377] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 06/18/2015] [Indexed: 05/09/2023]
Abstract
Recently, microbiologists have focused on characterizing the probiotic role of skin bacteria for amphibians threatened by the fungal disease chytridiomycosis. However, the specific characteristics of microbial diversity required to maintain health or trigger disease are still not well understood in natural populations. We hypothesized that seasonal and developmental transitions affecting susceptibility to chytridiomycosis could also alter the stability of microbial assemblages. To test our hypothesis, we examined patterns of skin bacterial diversity in two species of declining amphibians (Lithobates yavapaiensis and Eleutherodactylus coqui) affected by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We focused on two important transitions that affect Bd susceptibility: ontogenetic (from juvenile to adult) shifts in E. coqui and seasonal (from summer to winter) shifts in L. yavapaiensis. We used a combination of community-fingerprinting analyses and 16S rRNA amplicon sequencing to quantify changes in bacterial diversity and assemblage composition between seasons and developmental stages, and to investigate the relationship between bacterial diversity and pathogen load. We found that winter-sampled frogs and juveniles, two states associated with increased Bd susceptibility, exhibited higher diversity compared with summer-sampled frogs and adult individuals. Our findings also revealed that hosts harbouring higher bacterial diversity carried lower Bd infections, providing support for the protective role of bacterial communities. Ongoing work to understand skin microbiome resilience after pathogen disturbance has the potential to identify key taxa involved in disease resistance.
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Affiliation(s)
- Ana V. Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Author for correspondence: Ana V. Longo e-mail:
| | - Anna E. Savage
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Biology, University of Central Florida, Orlando, FL 32816, USA
| | - Ian Hewson
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
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Kolby JE, Smith KM, Ramirez SD, Rabemananjara F, Pessier AP, Brunner JL, Goldberg CS, Berger L, Skerratt LF. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar. PLoS One 2015; 10:e0125330. [PMID: 26083349 PMCID: PMC4471163 DOI: 10.1371/journal.pone.0125330] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/11/2015] [Indexed: 12/03/2022] Open
Abstract
We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease. Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot.
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Affiliation(s)
- Jonathan E. Kolby
- One Health Research Group, College of Public Health, Medical, and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
- EcoHealth Alliance, New York, New York, United States of America
- * E-mail:
| | | | - Sara D. Ramirez
- Sustainability Studies Program, Ramapo College of New Jersey, Mahwah, New Jersey, United States of America
| | | | - Allan P. Pessier
- Amphibian Disease Laboratory, Institute for Conservation Research, San Diego Zoo Global, San Diego, California, United States of America
| | - Jesse L. Brunner
- School of Biological Sciences, Washington State University, Pullman, Washington, United States of America
| | - Caren S. Goldberg
- School of the Environment, Washington State University, Pullman, Washington, United States of America
| | - Lee Berger
- One Health Research Group, College of Public Health, Medical, and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | - Lee F. Skerratt
- One Health Research Group, College of Public Health, Medical, and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
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Quintero E, Thessen AE, Arias-Caballero P, Ayala-Orozco B. A statistical assessment of population trends for data deficient Mexican amphibians. PeerJ 2014; 2:e703. [PMID: 25548736 PMCID: PMC4273930 DOI: 10.7717/peerj.703] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 11/28/2014] [Indexed: 11/20/2022] Open
Abstract
Background. Mexico has the world’s fifth largest population of amphibians and the second country with the highest quantity of threatened amphibian species. About 10% of Mexican amphibians lack enough data to be assigned to a risk category by the IUCN, so in this paper we want to test a statistical tool that, in the absence of specific demographic data, can assess a species’ risk of extinction, population trend, and to better understand which variables increase their vulnerability. Recent studies have demonstrated that the risk of species decline depends on extrinsic and intrinsic traits, thus including both of them for assessing extinction might render more accurate assessment of threats. Methods. We harvested data from the Encyclopedia of Life (EOL) and the published literature for Mexican amphibians, and used these data to assess the population trend of some of the Mexican species that have been assigned to the Data Deficient category of the IUCN using Random Forests, a Machine Learning method that gives a prediction of complex processes and identifies the most important variables that account for the predictions. Results. Our results show that most of the data deficient Mexican amphibians that we used have decreasing population trends. We found that Random Forests is a solid way to identify species with decreasing population trends when no demographic data is available. Moreover, we point to the most important variables that make species more vulnerable for extinction. This exercise is a very valuable first step in assigning conservation priorities for poorly known species.
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Affiliation(s)
- Esther Quintero
- Subcoordinación de Especies Prioritarias, Dirección General de Análisis y Prioridades, Comisión Nacional para el Conocimiento y Uso de la Biodiversidad , Mexico D.F. , Mexico
| | - Anne E Thessen
- The Data Detektiv , Waltham, MA , USA ; The Ronin Institute for Independent Scholarship , Montclair, NJ , USA
| | - Paulina Arias-Caballero
- Subcoordinación de Especies Prioritarias, Dirección General de Análisis y Prioridades, Comisión Nacional para el Conocimiento y Uso de la Biodiversidad , Mexico D.F. , Mexico
| | - Bárbara Ayala-Orozco
- Subcoordinación de Especies Prioritarias, Dirección General de Análisis y Prioridades, Comisión Nacional para el Conocimiento y Uso de la Biodiversidad , Mexico D.F. , Mexico
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