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Borteiro C, Laufer G, Gobel N, Arleo M, Kolenc F, Cortizas S, Barrasso DA, de Sá RO, Soutullo A, Ubilla M, Martínez-Debat C. Widespread occurrence of the amphibian chytrid panzootic lineage in Uruguay is constrained by climate. DISEASES OF AQUATIC ORGANISMS 2024; 158:123-132. [PMID: 38813853 DOI: 10.3354/dao03783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes chytridiomycosis, a disease among the main causes of amphibian declines worldwide. However, Bd studies on Neotropical amphibians from temperate areas are scarce. We present a comprehensive survey of Bd in Uruguay, in temperate central eastern South America, carried out between 2006 and 2014. Skin swabs of 535 specimens of 21 native and exotic frogs were tested by PCR. We used individual-level data to examine the relationship between infection, climatic variables, and their effects on body condition and the number of prey items found in stomach contents. Infection was widespread in free-ranging anurans with an overall prevalence of 41.9%, detected in 15 native species, wild American bullfrogs Aquarana catesbeiana, and captive specimens of Ceratophrys ornata and Xenopus laevis. Three haplotypes of the Bd ITS region were identified in native amphibians, all belonging to the global panzootic lineage (BdGPL), of which only one was present in exotic hosts. Despite high infection frequencies in different anurans, we found no evidence of morbidity or mortality attributable to chytridiomycosis, and we observed no discernible impact on body condition or consumed prey. Climatic conditions at the time of our surveys suggested that the chance of infection is associated with monthly mean temperature, mean humidity, and total precipitation. Temperatures below 21°C combined with moderate humidity and pronounced rainfall may increase the likelihood of infection. Multiple haplotypes of BdGPL combined with high frequencies of infection suggest an enzootic pattern in native species, underscoring the need for continued monitoring.
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Affiliation(s)
- Claudio Borteiro
- Sección Herpetología, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
| | - Gabriel Laufer
- Área Biodiversidad y Conservación, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
- Vida Silvestre Uruguay, Montevideo 11100, Uruguay
| | - Noelia Gobel
- Área Biodiversidad y Conservación, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
- Vida Silvestre Uruguay, Montevideo 11100, Uruguay
| | - Mailén Arleo
- Sección Bioquímica, Departamento de Biología, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
| | - Francisco Kolenc
- Sección Herpetología, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
| | - Sofía Cortizas
- Grupo de Agroecología, Sustentabilidad y Medio Ambiente, Universidad Tecnológica del Uruguay, Durazno 97000, Uruguay
| | - Diego A Barrasso
- Instituto de Diversidad y Evolución Austral (IDEAus-CONICET), and Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia 'San Juan Bosco' (UNPSJB), Puerto Madryn 9120, Chubut, Argentina
| | - Rafael O de Sá
- Department of Biology, University of Richmond, Richmond, Virginia 23173, USA
| | - Alvaro Soutullo
- Departamento de Ecología y Gestión Ambiental, Centro Universitario Regional del Este, Punta del Este 20100, Universidad de la República, Uruguay
| | - Martin Ubilla
- Departamento de Paleontología-ICG, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
| | - Claudio Martínez-Debat
- Sección Bioquímica, Departamento de Biología, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
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2
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Noelker JE, Abreu Ruozzi V, Craig HM, Sckrabulis JP, Raffel TR. Glove decontamination procedures to prevent pathogen and DNA cross-contamination among frogs. DISEASES OF AQUATIC ORGANISMS 2024; 158:173-178. [PMID: 38813857 DOI: 10.3354/dao03793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Working with aquatic organisms often requires handling multiple individuals in a single session, potentially resulting in cross-contamination by live pathogens or DNA. Most researchers address this problem by disposing of gloves between animals. However, this generates excessive waste and may be impractical for processing very slippery animals that might be easier to handle with cotton gloves. We tested methods to decontaminate cotton or nitrile gloves after contamination with cultured Batrachochytrium dendrobatidis (Bd) or after handling heavily Bd-infected Xenopus laevis with layered cotton and nitrile gloves. Bleach eliminated detectable Bd DNA from culture-contaminated nitrile gloves, but gloves retained detectable Bd DNA following ethanol disinfection. After handling a Bd-infected frog, Bd DNA contamination was greatly reduced by removal of the outer cotton glove, after which either bleach decontamination or ethanol decontamination followed by drying hands with a paper towel lowered Bd DNA below the detection threshold of our assay. These results provide new options to prevent pathogen or DNA cross-contamination, especially when handling slippery aquatic organisms. However, tradeoffs should be considered when selecting an animal handling procedure, such as the potential for cotton gloves to abrade amphibian skin or disrupt skin mucus. Disposing of gloves between animals should remain the gold standard for maintaining biosecurity in sensitive situations.
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Affiliation(s)
- James E Noelker
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | | | - Hunter M Craig
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Jason P Sckrabulis
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Thomas R Raffel
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
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3
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Cordeiro IF, Lemes CGDC, Sanchez AB, da Silva AK, de Paula CH, de Matos RC, Ribeiro DF, de Matos JP, Garcia CCM, Beirão M, Becker CG, Pires MRS, Moreira LM. Amphibian tolerance to arsenic: microbiome-mediated insights. Sci Rep 2024; 14:10193. [PMID: 38702361 PMCID: PMC11068734 DOI: 10.1038/s41598-024-60879-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 04/29/2024] [Indexed: 05/06/2024] Open
Abstract
Amphibians are often recognized as bioindicators of healthy ecosystems. The persistence of amphibian populations in heavily contaminated environments provides an excellent opportunity to investigate rapid vertebrate adaptations to harmful contaminants. Using a combination of culture-based challenge assays and a skin permeability assay, we tested whether the skin-associated microbiota may confer adaptive tolerance to tropical amphibians in regions heavily contaminated with arsenic, thus supporting the adaptive microbiome principle and immune interactions of the amphibian mucus. At lower arsenic concentrations (1 and 5 mM As3+), we found a significantly higher number of bacterial isolates tolerant to arsenic from amphibians sampled at an arsenic contaminated region (TES) than from amphibians sampled at an arsenic free region (JN). Strikingly, none of the bacterial isolates from our arsenic free region tolerated high concentrations of arsenic. In our skin permeability experiment, where we tested whether a subset of arsenic-tolerant bacterial isolates could reduce skin permeability to arsenic, we found that isolates known to tolerate high concentrations of arsenic significantly reduced amphibian skin permeability to this metalloid. This pattern did not hold true for bacterial isolates with low arsenic tolerance. Our results describe a pattern of environmental selection of arsenic-tolerant skin bacteria capable of protecting amphibians from intoxication, which helps explain the persistence of amphibian populations in water bodies heavily contaminated with arsenic.
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Affiliation(s)
- Isabella Ferreira Cordeiro
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | | | - Angélica Bianchini Sanchez
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | - Ana Karla da Silva
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | - Camila Henriques de Paula
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | - Rosilene Cristina de Matos
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | - Dilson Fagundes Ribeiro
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | - Jéssica Pereira de Matos
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | - Camila Carrião Machado Garcia
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
- Laboratório de Genômica e Interação Bactérias-Ambiente, Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil
| | - Marina Beirão
- Departamento de Biodiversidade Evolução e Meio Ambiente, Instituto de Ciências Biológicas, Universidade Federal de Ouro Preto, Belo Horizonte, MG, 31270-901, Brazil
| | - C Guilherme Becker
- Department of Biology, One Health Microbiome Center, Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
| | - Maria Rita Silvério Pires
- Departamento de Biodiversidade Evolução e Meio Ambiente, Instituto de Ciências Biológicas, Universidade Federal de Ouro Preto, Belo Horizonte, MG, 31270-901, Brazil
| | - Leandro Marcio Moreira
- Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil.
- Laboratório de Genômica e Interação Bactérias-Ambiente, Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, 35400-000, Brazil.
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4
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Humphries JE, Lanctôt CM, McCallum HI, Newell DA, Grogan LF. Chytridiomycosis causes high amphibian mortality prior to the completion of metamorphosis. ENVIRONMENTAL RESEARCH 2024; 247:118249. [PMID: 38244972 DOI: 10.1016/j.envres.2024.118249] [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: 11/26/2023] [Revised: 01/09/2024] [Accepted: 01/17/2024] [Indexed: 01/22/2024]
Abstract
Amphibian populations are undergoing extensive declines globally. The fungal disease chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), is a primary contributor to these declines. The amphibian metamorphic stages (Gosner stages 42-46) are particularly vulnerable to a range of stressors, including Bd. Despite this, studies that explicitly examine host response to chytridiomycosis throughout the metamorphic stages are lacking. We aimed to determine how Bd exposure during the larval stages impacts metamorphic development and infection progression in the endangered Fleay's barred frog (Mixophyes fleayi). We exposed M. fleayi to Bd during pro-metamorphosis (Gosner stages 35-38) and monitored infection dynamics throughout metamorphosis. We took weekly morphological measurements (weight, total body length, snout-vent-length and Gosner stage) and quantified Bd load using qPCR. While we observed minimal impact of Bd infection on animal growth and development, Bd load varied throughout ontogeny, with an infection load plateau during the tadpole stages (Gosner stages 35-41) and temporary infection clearance at Gosner stage 42. Bd load increased exponentially between Gosner stages 42 and 45, with most exposed animals becoming moribund at Gosner stage 45, prior to the completion of metamorphosis. There was variability in infection outcome of exposed individuals, with a subgroup of animals (n = 5/29) apparently clearing their infection while the majority (n = 21/29) became moribund with high infection burdens. This study demonstrates the role that metamorphic restructuring plays in shaping Bd infection dynamics and raises the concern that substantial Bd-associated mortality could be overlooked in the field due to the often cryptic nature of these latter metamorphic stages. We recommend future studies that directly examine the host immune response to Bd infection throughout metamorphosis, incorporating histological and molecular methods to elucidate the mechanisms responsible for the observed trends.
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Affiliation(s)
- Josephine E Humphries
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia; Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland 4222, Australia.
| | - Chantal M Lanctôt
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia; Australian Rivers Institute, Griffith University, Southport, Queensland 4222, Australia
| | - Hamish I McCallum
- Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland 4222, Australia
| | - David A Newell
- Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales 2480, Australia
| | - Laura F Grogan
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia; Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland 4222, Australia
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5
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Blanvillain G, Lorch JM, Joudrier N, Bury S, Cuenot T, Franzen M, Martínez-Freiría F, Guiller G, Halpern B, Kolanek A, Kurek K, Lourdais O, Michon A, Musilová R, Schweiger S, Szulc B, Ursenbacher S, Zinenko O, Hoyt JR. Contribution of host species and pathogen clade to snake fungal disease hotspots in Europe. Commun Biol 2024; 7:440. [PMID: 38600171 PMCID: PMC11006896 DOI: 10.1038/s42003-024-06092-x] [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: 11/10/2023] [Accepted: 03/22/2024] [Indexed: 04/12/2024] Open
Abstract
Infectious diseases are influenced by interactions between host and pathogen, and the number of infected hosts is rarely homogenous across the landscape. Areas with elevated pathogen prevalence can maintain a high force of infection and may indicate areas with disease impacts on host populations. However, isolating the ecological processes that result in increases in infection prevalence and intensity remains a challenge. Here we elucidate the contribution of pathogen clade and host species in disease hotspots caused by Ophidiomyces ophidiicola, the pathogen responsible for snake fungal disease, in 21 species of snakes infected with multiple pathogen strains across 10 countries in Europe. We found isolated areas of disease hotspots in a landscape where infections were otherwise low. O. ophidiicola clade had important effects on transmission, and areas with multiple pathogen clades had higher host infection prevalence. Snake species further influenced infection, with most positive detections coming from species within the Natrix genus. Our results suggest that both host and pathogen identity are essential components contributing to increased pathogen prevalence.
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Affiliation(s)
- Gaëlle Blanvillain
- Biological Sciences Department, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
| | - Jeffrey M Lorch
- U.S. Geological Survey, National Wildlife Health Center, Madison, WI, USA
| | - Nicolas Joudrier
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Institute of Animal Pathology, University of Bern, Bern, Switzerland
- Info fauna-Karch, Centre Suisse de Cartographie de la Faune (CSCF) and Centre de coordination pour la protection des reptiles et des amphibiens de Suisse (karch), Neuchâtel, Switzerland
| | - Stanislaw Bury
- Department of Comparative Anatomy, Institute of Zoology and Biomedical Research, Jagiellonian University, Cracow, Poland
- NATRIX Herpetological Association, Wroclaw, Poland
| | - Thibault Cuenot
- LPO Bourgogne-Franche-Comté, Site de Franche-Comté, Maison de l'environnement de BFC, Besançon, France
| | - Michael Franzen
- Bavarian State Collection of Zoology (ZSM-SNSB), Munich, Germany
| | - Fernando Martínez-Freiría
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, University of Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
| | | | - Bálint Halpern
- MME BirdLife Hungary, Budapest, Hungary
- Department of Systematic Zoology and Ecology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE-MTM, Integrative Ecology Research Group, Budapest, Hungary
| | - Aleksandra Kolanek
- NATRIX Herpetological Association, Wroclaw, Poland
- Department of Geoinformatics and Cartography, Institute of Geography and Regional Development, Faculty of Earth Sciences and Environmental Management, University of Wroclaw, Wroclaw, Poland
| | - Katarzyna Kurek
- Department of Wildlife Conservation, Institute of Nature Conservation Polish Academy of Science, Cracow, Poland
| | - Olivier Lourdais
- Centre d'Etudes Biologiques de Chizé, ULR CNRS UMR 7372, Villiers en Bois, France
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Alix Michon
- LPO Bourgogne-Franche-Comté, Site de Franche-Comté, Maison de l'environnement de BFC, Besançon, France
| | | | - Silke Schweiger
- First Zoological Department, Herpetological Collection, Natural History Museum, Vienna, Austria
| | - Barbara Szulc
- NATRIX Herpetological Association, Wroclaw, Poland
- Department of Genetics, Kazimierz Wielki University, Bydgoszcz, Poland
| | - Sylvain Ursenbacher
- Info fauna-Karch, Centre Suisse de Cartographie de la Faune (CSCF) and Centre de coordination pour la protection des reptiles et des amphibiens de Suisse (karch), Neuchâtel, Switzerland
- Department of Environmental Sciences, Section of Conservation Biology, University of Basel, Basel, Switzerland
- Balaton Limnological Research Institute, Tihany, Hungary
| | | | - Joseph R Hoyt
- Biological Sciences Department, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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6
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Salla RF, Costa MJ, Abdalla FC, Oliveira CR, Tsukada E, Boeing GANS, Prado J, Carvalho T, Ribeiro LP, Rebouças R, Toledo LF. Estrogen contamination increases vulnerability of amphibians to the deadly chytrid fungus. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170337. [PMID: 38301782 DOI: 10.1016/j.scitotenv.2024.170337] [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: 10/16/2023] [Revised: 12/31/2023] [Accepted: 01/19/2024] [Indexed: 02/03/2024]
Abstract
Aquatic contaminants and infectious diseases are among the major drivers of global amphibian declines. However, the interaction of these factors is poorly explored and could better explain the amphibian crisis. We exposed males and females of the Brazilian Cururu Toad, Rhinella icterica, to an environmentally relevant concentration of the estrogen 17-alpha-ethinylestradiol (an emerging contaminant) and to the chytrid infection (Batrachochytrium dendrobatidis), in their combined and isolated forms, and the ecotoxicity was determined by multiple biomarkers: cutaneous, hematological, cardiac, hepatic, and gonadal analysis. Our results showed that Cururu toads had many physiological alterations in response to the chytrid infection, including the appearance of cutaneous Langerhans's cells, increased blood leukocytes, increased heart contraction force and tachycardia, increased hepatic melanomacrophage cells, which in turn led to gonadal atrophy. The estrogen, in turn, increased the susceptibility of the toads to the chytrid infection (higher Bd loads) and maximized the deleterious effects of the pathogen: reducing leukocytes, decreasing the contraction force, and causing greater tachycardia, increasing hepatic melanomacrophage cells, and leading to greater gonadal atrophy, which were more extreme in females. The exposure to estrogen also revealed important toxicodynamic pathways of this toxicant, as shown by the immunosuppression of exposed animals, and the induction of the first stages of feminization in males, which corroborates that the synthetic estrogen acts as an endocrine disruptor. Such an intricate relationship is unprecedented and reinforces the importance of studying the serious consequences that multiple environmental stressors can cause to aquatic populations.
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Affiliation(s)
- Raquel F Salla
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil; Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil.
| | - Monica Jones Costa
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil; Laboratório de Fisiologia da Conservação (LaFisC), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Fabio Camargo Abdalla
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil; Laboratório de Biologia Estrutural e Funcional (LaBEF), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Cristiane R Oliveira
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Elisabete Tsukada
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Guilherme Andrade Neto Schmitz Boeing
- Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental (PPGBMA), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil; Laboratório de Biologia Estrutural e Funcional (LaBEF), Universidade Federal de São Carlos, Sorocaba, São Paulo, Brazil
| | - Joelma Prado
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
| | - Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Luisa P Ribeiro
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
| | - Raoni Rebouças
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil
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7
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Allain SJR, Leech DI, Hopkins K, Seilern-Moy K, Rodriguez-Ramos Fernandez J, Griffiths RA, Lawson B. Characterisation, prevalence and severity of skin lesions caused by ophidiomycosis in a population of wild snakes. Sci Rep 2024; 14:5162. [PMID: 38431688 PMCID: PMC10908839 DOI: 10.1038/s41598-024-55354-5] [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: 11/14/2023] [Accepted: 02/22/2024] [Indexed: 03/05/2024] Open
Abstract
Ophidiomycosis is an emerging infectious disease affecting wild snakes in the Northern Hemisphere. Recently confirmed in Great Britain, the prevalence, severity and significance of ophidiomycosis has yet to be characterised in free-living snakes at a population level in Europe. Therefore, a population of barred grass snakes (Natrix helvetica) in eastern England was monitored for three seasons (May 2019 to October 2021), to investigate the prevalence (25.5%; 191/750 snakes) and severity of skin lesions and their aetiology. The most frequently observed skin lesion characteristics were changes in scale colour, crusting, and scale margin erosion. The majority of such lesions (96.9%; 185/191 snakes) was observed on the ventral surface along the length of the body. The severity of skin lesions was considered mild in more than half of the cases (53.1%; 98/191 snakes). Predominantly, skin lesions were observed in adult snakes (72.8%; 139/191 snakes). Combined histological examinations and qPCR tests of skin lesions from N. helvetica sloughs and/or carcasses confirmed a diagnosis of ophidiomycosis. Further targeted surveillance, supported by molecular and histological examinations to confirm skin lesion aetiology, is required to determine the extent to which our findings reflect the occurrence of ophidiomycosis in populations within wider landscapes.
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Affiliation(s)
- Steven J R Allain
- Durrell Institute of Ecology and Conservation, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - David I Leech
- British Trust for Ornithology, The Nunnery, Thetford, Norfolk, IP24 2PU, UK
| | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Katharina Seilern-Moy
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | | | - Richard A Griffiths
- Durrell Institute of Ecology and Conservation, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK.
| | - Becki Lawson
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
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8
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Sun X, Guo N, Gao J, Xiao N. Using eDNA to survey amphibians: Methods, applications, and challenges. Biotechnol Bioeng 2024; 121:456-471. [PMID: 37986625 DOI: 10.1002/bit.28592] [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: 08/16/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/22/2023]
Abstract
In recent years, environmental DNA (eDNA) has received attention from biologists due to its sensitivity, convenience, labor and material efficiency, and lack of damage to organisms. The extensive application of eDNA has opened avenues for the monitoring and biodiversity assessment of amphibians, which are frequently small and difficult to observe in the field, in areas such as biodiversity survey assessment and detection of specific, rare and threatened, or alien invasive species. However, the accuracy of eDNA can be influenced by factors such as ambient temperature, pH, and false positives or false negatives, which makes eDNA an adjunctive tool rather than a replacement for traditional surveys. This review provides a concise overview of the eDNA method and its workflow, summarizes the differences between applying eDNA for detecting amphibians and other organisms, reviews the research progress in eDNA technology for amphibian monitoring, identifies factors influencing detection efficiency, and discusses the challenges and prospects of eDNA. It aims to serve as a reference for future research on the application of eDNA in amphibian detection.
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Affiliation(s)
- Xiaoxuan Sun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Ningning Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Jianan Gao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
- Collage of Forestry, Shanxi Agricultural University, Jinzhong, China
| | - Nengwen Xiao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
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Mulder KP, Savage AE, Gratwicke B, Longcore JE, Bronikowski E, Evans M, Longo AV, Kurata NP, Walsh T, Pasmans F, McInerney N, Murray S, Martel A, Fleischer RC. Sequence capture identifies fastidious chytrid fungi directly from host tissue. Fungal Genet Biol 2024; 170:103858. [PMID: 38101696 DOI: 10.1016/j.fgb.2023.103858] [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: 04/20/2023] [Revised: 12/04/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
The chytrid fungus Batrachochytrium dendrobatidis (Bd) was discovered in 1998 as the cause of chytridiomycosis, an emerging infectious disease causing mass declines in amphibian populations worldwide. The rapid population declines of the 1970s-1990s were likely caused by the spread of a highly virulent lineage belonging to the Bd-GPL clade that was introduced to naïve susceptible populations. Multiple genetically distinct and regional lineages of Bd have since been isolated and sequenced, greatly expanding the known biological diversity within this fungal pathogen. To date, most Bd research has been restricted to the limited number of samples that could be isolated using culturing techniques, potentially causing a selection bias for strains that can grow on media and missing other unculturable or fastidious strains that are also present on amphibians. We thus attempted to characterize potentially non-culturable genetic lineages of Bd from distinct amphibian taxa using sequence capture technology on DNA extracted from host tissue and swabs. We focused our efforts on host taxa from two different regions that likely harbored distinct Bd clades: (1) wild-caught leopard frogs (Rana) from North America, and (2) a Japanese Giant Salamander (Andrias japonicus) at the Smithsonian Institution's National Zoological Park that exhibited signs of disease and tested positive for Bd using qPCR, but multiple attempts failed to isolate and culture the strain for physiological and genetic characterization. We successfully enriched for and sequenced thousands of fungal genes from both host clades, and Bd load was positively associated with number of recovered Bd sequences. Phylogenetic reconstruction placed all the Rana-derived strains in the Bd-GPL clade. In contrast, the A. japonicus strain fell within the Bd-Asia3 clade, expanding the range of this clade and generating additional genomic data to confirm its placement. The retrieved ITS locus matched public barcoding data from wild A. japonicus and Bd infections found on other amphibians in India and China, suggesting that this uncultured clade is widespread across Asia. Our study underscores the importance of recognizing and characterizing the hidden diversity of fastidious strains in order to reconstruct the spatiotemporal and evolutionary history of Bd. The success of the sequence capture approach highlights the utility of directly sequencing pathogen DNA from host tissue to characterize cryptic diversity that is missed by culture-reliant approaches.
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Affiliation(s)
- Kevin P Mulder
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium; Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA.
| | - Anna E Savage
- Department of Biology, University of Central Florida, Orlando, FL, USA
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Joyce E Longcore
- School of Biology and Ecology, University of Maine, Orono, ME, USA
| | - Ed Bronikowski
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Matthew Evans
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Naoko P Kurata
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA; Department of Natural Resources and the Environment, Cornell University, Ithaca, NY, USA; Department of Ichthyology, American Museum of Natural History, New York, NY, USA
| | - Tim Walsh
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Frank Pasmans
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Nancy McInerney
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Suzan Murray
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - An Martel
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Robert C Fleischer
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
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10
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Schuck LK, Neely WJ, Buttimer SM, Moser CF, Barth PC, Liskoski PE, Caberlon CDA, Valiati VH, Tozetti AM, Becker CG. Effects of grassland controlled burning on symbiotic skin microbes in Neotropical amphibians. Sci Rep 2024; 14:959. [PMID: 38200064 PMCID: PMC10781984 DOI: 10.1038/s41598-023-50394-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
Climate change has led to an alarming increase in the frequency and severity of wildfires worldwide. While it is known that amphibians have physiological characteristics that make them highly susceptible to fire, the specific impacts of wildfires on their symbiotic skin bacterial communities (i.e., bacteriomes) and infection by the deadly chytrid fungus, Batrachochytrium dendrobatidis, remain poorly understood. Here, we address this research gap by evaluating the effects of fire on the amphibian skin bacteriome and the subsequent risk of chytridiomycosis. We sampled the skin bacteriome of the Neotropical species Scinax squalirostris and Boana leptolineata in fire and control plots before and after experimental burnings. Fire was linked with a marked increase in bacteriome beta dispersion, a proxy for skin microbial dysbiosis, alongside a trend of increased pathogen loads. By shedding light on the effects of fire on amphibian skin bacteriomes, this study contributes to our broader understanding of the impacts of wildfires on vulnerable vertebrate species.
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Affiliation(s)
- Laura K Schuck
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil.
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Wesley J Neely
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35487, USA
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA
| | - Shannon M Buttimer
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Infectious Disease Dynamics and One Health Microbiome Center, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Camila F Moser
- Programa de Pos-Graduacão em Zoologia, Universidade Federal do Pará, Belém, PA, 66075-110, Brazil
| | - Priscila C Barth
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Paulo E Liskoski
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Carolina de A Caberlon
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Victor Hugo Valiati
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Alexandro M Tozetti
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil.
| | - C Guilherme Becker
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
- Center for Infectious Disease Dynamics and One Health Microbiome Center, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
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11
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Porco D, Purnomo CA, Glesener L, Proess R, Lippert S, Jans K, Colling G, Schneider S, Stassen R, Frantz AC. eDNA-based monitoring of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans with ddPCR in Luxembourg ponds: taking signals below the Limit of Detection (LOD) into account. BMC Ecol Evol 2024; 24:4. [PMID: 38178008 PMCID: PMC10768104 DOI: 10.1186/s12862-023-02189-9] [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: 08/07/2023] [Accepted: 12/09/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) are two pathogenic fungi that are a significant threat to amphibian communities worldwide. European populations are strongly impacted and the monitoring of the presence and spread of these pathogens is crucial for efficient decision-making in conservation management. RESULTS Here we proposed an environmental DNA (eDNA) monitoring of these two pathogenic agents through droplet digital PCR (ddPCR) based on water samples from 24 ponds in Luxembourg. In addition, amphibians were swabbed in eight of the targeted ponds in order to compare the two approaches at site-level detection. This study allowed the development of a new method taking below-Limit of Detection (LOD) results into account thanks to the statistical comparison of the frequencies of false positives in no template controls (NTC) and below-LOD results in technical replicates. In the eDNA-based approach, the use of this method led to an increase in Bd and Bsal detection of 28 and 50% respectively. In swabbing, this resulted in 8% more positive results for Bd. In some samples, the use of technical replicates allowed to recover above-LOD signals and increase Bd detection by 35 and 33% respectively for eDNA and swabbing, and Bsal detection by 25% for eDNA. CONCLUSIONS These results confirmed the usefulness of technical replicates to overcome high levels of stochasticity in very low concentration samples even for a highly sensitive technique such as ddPCR. In addition, it showed that below-LOD signals could be consistently recovered and the corresponding amplification events assigned either to positive or negative detection via the method developed here. This methodology might be particularly worth pursuing in pathogenic agents' detection as false negatives could have important adverse consequences. In total, 15 ponds were found positive for Bd and four for Bsal. This study reports the first record of Bsal in Luxembourg.
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Affiliation(s)
- David Porco
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg.
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg.
| | - Chanistya Ayu Purnomo
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Liza Glesener
- Naturschutzsyndikat SICONA, 12, rue de Capellen, L-8393 Olm, Luxembourg, Luxembourg
| | - Roland Proess
- Umweltplanungsbüro Ecotop, 45, Schlassuecht, L-7435 Hollenfels, Luxembourg, Luxembourg
| | - Stéphanie Lippert
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Kevin Jans
- Natur&ëmwelt Fondation Hëllef fir d'Natur, 5, Route de Luxembourg, L-1899, Kockelscheuer, Luxembourg
| | - Guy Colling
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Simone Schneider
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Naturschutzsyndikat SICONA, 12, rue de Capellen, L-8393 Olm, Luxembourg, Luxembourg
| | - Raf Stassen
- Biota.lu, 9a, Rue Principale, L-6990, Hostert, Luxembourg
| | - Alain C Frantz
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg
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12
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Buttimer S, Moura-Campos D, Greenspan SE, Neely WJ, Ferrante L, Toledo LF, Becker CG. Skin microbiome disturbance linked to drought-associated amphibian disease. Ecol Lett 2024; 27:e14372. [PMID: 38288868 DOI: 10.1111/ele.14372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 02/01/2024]
Abstract
The onset of global climate change has led to abnormal rainfall patterns, disrupting associations between wildlife and their symbiotic microorganisms. We monitored a population of pumpkin toadlets and their skin bacteria in the Brazilian Atlantic Forest during a drought. Given the recognized ability of some amphibian skin bacteria to inhibit the widespread fungal pathogen Batrachochytrium dendrobatidis (Bd), we investigated links between skin microbiome health, susceptibility to Bd and host mortality during a die-off event. We found that rainfall deficit was an indirect predictor of Bd loads through microbiome disruption, while its direct effect on Bd was weak. The microbiome was characterized by fewer putative Bd-inhibitory bacteria following the drought, which points to a one-month lagged effect of drought on the microbiome that may have increased toadlet susceptibility to Bd. Our study underscores the capacity of rainfall variability to disturb complex host-microbiome interactions and alter wildlife disease dynamics.
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Affiliation(s)
- Shannon Buttimer
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
- One Health Microbiome Center, Center for Infectious Disease Dynamics, Ecology Institute, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Diego Moura-Campos
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Sasha E Greenspan
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA
| | - Wesley J Neely
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA
- Department of Biology, Texas State University, San Marcos, Texas, USA
| | - Lucas Ferrante
- Universidade Federal do Amazonas, Manaus, Amazonas, Brazil
| | - Luís Felipe Toledo
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - C Guilherme Becker
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
- One Health Microbiome Center, Center for Infectious Disease Dynamics, Ecology Institute, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
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13
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Belasen AM, Peek RA, Adams AJ, Russell ID, De León ME, Adams MJ, Bettaso J, Breedveld KGH, Catenazzi A, Dillingham CP, Grear DA, Halstead BJ, Johnson PG, Kleeman PM, Koo MS, Koppl CW, Lauder JD, Padgett-Flohr G, Piovia-Scott J, Pope KL, Vredenburg V, Westphal M, Wiseman K, Kupferberg SJ. Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231270. [PMID: 38298390 PMCID: PMC10827429 DOI: 10.1098/rsos.231270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024]
Abstract
Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog (Rana boylii) inhabits a wide geographical range and variable conditions in rivers of California and Oregon (USA), and is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd). To assess drivers of Bd infections over time and space, we compiled over 2000 datapoints from R. boylii museum specimens (collected 1897-2005) and field samples (2005-2021) spanning 9° of latitude. We observed a south-to-north spread of Bd detections beginning in the 1940s and increase in prevalence from the 1940s to 1970s, coinciding with extirpation from southern latitudes. We detected eight high-prevalence geographical clusters through time that span the species' geographical range. Field-sampled male R. boylii exhibited the highest prevalence, and juveniles sampled in autumn exhibited the highest loads. Bd infection risk was highest in lower elevation rain-dominated watersheds, and with cool temperatures and low stream-flow conditions at the end of the dry season. Through a holistic assessment of relationships between infection risk, geographical context and time, we identify the locations and time periods where Bd mitigation and monitoring will be critical for conservation of this imperilled species.
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Affiliation(s)
- A. M. Belasen
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - R. A. Peek
- California Department of Fish and Wildlife, West Sacramento, CA, USA
| | - A. J. Adams
- Earth Research Institute, University of California, Santa Barbara, CA, USA
| | - I. D. Russell
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - M. E. De León
- Genome Center, University of California, Davis, CA, USA
| | - M. J. Adams
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, USA
| | - J. Bettaso
- Six Rivers National Forest, Lower Trinity Ranger District, USDA Forest Service, P.O. Box 68, Willow Creek, CA, USA
| | | | - A. Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL, USA
| | | | - D. A. Grear
- U.S. Geological Survey, National Wildlife Health Center, Madison, WI, USA
| | - B. J. Halstead
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - P. G. Johnson
- Pinnacles National Park, National Park Service, Paicines, CA, USA
| | - P. M. Kleeman
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - M. S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, CA
| | - C. W. Koppl
- Plumas National Forest, USDA Forest Service, Quincy, CA, USA
| | | | | | - J. Piovia-Scott
- School of Biological Sciences, Washington State University, Vancouver, WA, USA
| | - K. L. Pope
- Pacific Southwest Research Station, USDA Forest Service, Arcata, CA, USA
| | - V. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - M. Westphal
- Central Coast Field Office, United States Bureau of Land Management, Marina, CA, USA
| | - K. Wiseman
- Department of Herpetology, California Academy of Sciences, San Francisco, CA, USA
| | - S. J. Kupferberg
- Department of Integrative Biology, University of California, Berkeley, CA, USA
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14
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Mantzana-Oikonomaki V, Desreveaux A, Preißler K, Maan ME, Spitzen-van der Sluijs A, Sabino-Pinto J. FIRST RECORD OF BATRACHOCHYTRIUM DENDROBATIDIS IN THE NORTHERN NETHERLANDS. J Parasitol 2024; 110:11-16. [PMID: 38232760 DOI: 10.1645/22-126] [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] [Indexed: 01/19/2024] Open
Abstract
Batrachochytrium dendrobatidis (Bd) infects amphibians and has been linked to the decline of hundreds of anuran amphibians all over the world. In the province of Groningen in the Netherlands, this fungal pathogen was not detected before this study. To determine whether Groningen was Bd-free, we surveyed 12 locations in this province in 2020 and 2021. Samples were then used to quantify the presence of Bd with a qPCR assay. In total, 2 out of 110 (∼0.02%) collected in 2020 and 11 out of 249 samples collected in 2021 tested positive for Bd. Infected amphibians were found in 4 out of the 12 sites, and the prevalence of Bd was estimated at 4% for both years combined. Our study provides the first record of Bd in Groningen, and we hypothesize that Bd is present throughout the Netherlands in regions currently considered "Bd-free." Furthermore, we warn scientists and policymakers to be apprehensive when calling a site free from Bd when sampling is limited or not recent.
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Affiliation(s)
- Vasiliki Mantzana-Oikonomaki
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Anne Desreveaux
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Kathleen Preißler
- Institute of Biology, Molecular Evolution and Systematics of Animals, University of Leipzig, Talstraße 33, 04103 Leipzig, Germany
| | - Martine E Maan
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Annemarieke Spitzen-van der Sluijs
- Reptile, Amphibian and Fish Conservation Netherlands (RAVON), PO Box 1413, 5601 BK Nijmegen, The Netherlands
- Institute for Water and Wetland Research, Animal Ecology and Physiology, Radboud Universiteit, PO Box 9010, 6500 GL Nijmegen, The Netherlands
| | - Joana Sabino-Pinto
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
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15
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Meurling S, Siljestam M, Cortazar-Chinarro M, Åhlen D, Rödin-Mörch P, Ågren E, Höglund J, Laurila A. Body size mediates latitudinal population differences in the response to chytrid fungus infection in two amphibians. Oecologia 2024; 204:71-81. [PMID: 38097779 PMCID: PMC10830819 DOI: 10.1007/s00442-023-05489-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/14/2023] [Indexed: 02/02/2024]
Abstract
Factors behind intraspecific variation in sensitivity to pathogens remain poorly understood. We investigated how geographical origin in two North European amphibians affects tolerance to infection by the chytrid fungus Batrachochytrium dendrobatidis (Bd), a generalist pathogen which has caused amphibian population declines worldwide. We exposed newly metamorphosed individuals of moor frog Rana arvalis and common toad Bufo bufo from two latitudinal regions to two different BdGPL strains. We measured survival and growth as infections may cause sub-lethal effects in fitness components even in the absence of mortality. Infection loads were higher in B. bufo than in R. arvalis, and smaller individuals had generally higher infection loads. B. bufo had high mortality in response to Bd infection, whereas there was little mortality in R. arvalis. Bd-mediated mortality was size-dependent and high-latitude individuals were smaller leading to high mortality in the northern B. bufo. Bd exposure led to sub-lethal effects in terms of reduced growth suggesting that individuals surviving the infection may have reduced fitness mediated by smaller body size. In both host species, the Swedish Bd strain caused stronger sublethal effects than the British strain. We suggest that high-latitude populations can be more vulnerable to chytrids than those from lower latitudes and discuss the possible mechanisms how body size and host geographical origin contribute to the present results.
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Affiliation(s)
- Sara Meurling
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Mattias Siljestam
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Maria Cortazar-Chinarro
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
- MEMEG/Department of Biology, Lund University, Lund, Sweden
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada
| | - David Åhlen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Uppsala, Sweden
| | - Patrik Rödin-Mörch
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Erik Ågren
- Department of Pathology and Wildlife Diseases, National Veterinary Institute, Uppsala, Sweden
| | - Jacob Höglund
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Anssi Laurila
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
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16
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Herrera-Alva V, Catenazzi A, Aguilar-Puntriano C. A new cryptic species of terrestrial breeding frog of the Pristimantisdanae Group (Anura, Strabomantidae) from montane forests in Ayacucho, Peru. Zookeys 2023; 1187:1-29. [PMID: 38161710 PMCID: PMC10756142 DOI: 10.3897/zookeys.1187.104536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/21/2023] [Indexed: 01/03/2024] Open
Abstract
Based on morphological and molecular characters, we describe a new species of terrestrial breeding frog of the Pristimantisdanae Group from montane forests of La Mar Province, Ayacucho Department in southern Peru, at elevations from 1200 to 2000 m a.s.l. The phylogenetic analysis, based on concatenated sequences of gene fragments of 16S rRNA, RAG1, COI and TYR suggests that the new species is a sister taxon of a clade that includes one undescribed species of Pristimantis from Cusco, Pristimantispharangobates and Pristimantisrhabdolaemus. The new species is most similar to P.rhabdolaemus, which differs by lacking scapular tubercules and by its smaller size (17.0-18.6 mm in males [n = 5], 20.8-25.2 mm in females [n = 5] in the new species vs. 22.8-26.3 mm in males [n = 19], 26.0-31.9 mm in females [n = 30] of P.rhabdolaemus). Additionally, we report the prevalence of Batrachochytriumdendrobatidis (Bd) in this species.
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Affiliation(s)
- Valia Herrera-Alva
- Departamento de Herpetología, Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos, Lima, PeruMuseo de Historia Natural de la Universidad Nacional Mayor de San MarcosLimaPeru
- Laboratorio de Sistemática y Ecología de Vertebrados, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, PeruUniversidad Nacional Mayor de San MarcosLimaPeru
| | - Alessandro Catenazzi
- Florida International University, Department of Biological Sciences, 11200 SW 8th Street, Miami, FL 33199, USAFlorida International UniversityMiamiUnited States of America
| | - César Aguilar-Puntriano
- Departamento de Herpetología, Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos, Lima, PeruMuseo de Historia Natural de la Universidad Nacional Mayor de San MarcosLimaPeru
- Laboratorio de Sistemática y Ecología de Vertebrados, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, PeruUniversidad Nacional Mayor de San MarcosLimaPeru
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17
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Campos PM, Lucid MK, Ehlers S, Walke JB. Low-level pathogen infection and geographic location correlate with the skin microbiomes of Columbia spotted frogs ( Rana luteiventris) in a montane landscape. CURRENT RESEARCH IN MICROBIAL SCIENCES 2023; 6:100213. [PMID: 38187998 PMCID: PMC10770434 DOI: 10.1016/j.crmicr.2023.100213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024] Open
Abstract
The skin microbiome of amphibians can influence host susceptibility towards the fungal pathogen Batrachochytrium dendrobatidis (Bd), while simultaneously having the potential to be altered by Bd. Severe Bd infections are known to alter the amphibian skin microbiome; however, little is known about microbiome interactions in amphibians with low infection intensity. In addition to disease dynamics, environmental factors may influence the microbiome. To test for patterns in bacterial diversity based on pathogen infection and environmental factors, 399 Columbia spotted frogs (Rana luteiventris) were sampled throughout northern Idaho and northeastern Washington across two years. Bd prevalence and intensity were measured in 376 frogs, revealing a prevalence of 69%, but generally low infection intensity (Mean = 127 Bd zoospore equivalents among infected frogs). Skin bacterial communities were characterized in 92 frogs using 16S rRNA gene amplicon sequencing. Our results indicated correlations of decreasing Shannon diversity and evenness as infection intensity increased. Latitude was correlated with bacterial richness and Faith's Phylogenetic Diversity measures, indicating increased diversity in northern locations. Beta diversity (UniFrac) analyses revealed that skin microbiomes were distinct between infected and uninfected frogs, and infection intensity had a significant effect on microbiome composition. Site explained the majority of microbiome variation (weighted UniFrac: 57.5%), suggesting a combination of local habitat conditions explain variation, as only small proportions of variation could be explained by year, month, temperature, elevation, and latitude individually. Bacterial genera with potential for Bd-inhibitory properties were found with differential relative abundance in infected and uninfected frogs, with higher Stenotrophomonas and lower Pseudomonas relative abundance observed in infected frogs. Further study may indicate if Bd inhibition by members of the skin microbiome is an influence behind the low infection intensities observed and whether low Bd infection intensities are capable of altering skin microbiome composition.
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Affiliation(s)
- Philip M. Campos
- Department of Biology, Eastern Washington University, 1175 Washington St., Cheney, WA 99004, USA
| | - Michael K. Lucid
- Idaho Department of Fish and Game, 2885 Kathleen Ave., Coeur d'Alene, ID 83815, USA
- Selkirk Wildlife Science, LLC, PO Box 733, Sandpoint, ID 83864, USA
| | - Shannon Ehlers
- Idaho Department of Fish and Game, 2885 Kathleen Ave., Coeur d'Alene, ID 83815, USA
- U.S. Fish and Wildlife Service, 287 Westside Rd., Bonners Ferry, ID 83805, USA
| | - Jenifer B. Walke
- Department of Biology, Eastern Washington University, 1175 Washington St., Cheney, WA 99004, USA
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18
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Lorch JM, Winzeler ME, Lankton JS, Raverty S, Snyman HN, Schwantje H, Thacker C, Knowles S, Cai HY, Grear DA. Paranannizziopsis spp. infections in wild snakes and a qPCR assay for detection of the fungus. Front Microbiol 2023; 14:1302586. [PMID: 38125577 PMCID: PMC10730940 DOI: 10.3389/fmicb.2023.1302586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/06/2023] [Indexed: 12/23/2023] Open
Abstract
The emergence of ophidiomycosis (or snake fungal disease) in snakes has prompted increased awareness of the potential effects of fungal infections on wild reptile populations. Yet, aside from Ophidiomyces ophidiicola, little is known about other mycoses affecting wild reptiles. The closely related genus Paranannizziopsis has been associated with dermatomycosis in snakes and tuataras in captive collections, and P. australasiensis was recently identified as the cause of skin infections in non-native wild panther chameleons (Furcifer pardalis) in Florida, USA. Here we describe five cases of Paranannizziopsis spp. associated with skin lesions in wild snakes in North America and one additional case from a captive snake from Connecticut, USA. In addition to demonstrating that wild Nearctic snakes can serve as a host for these fungi, we also provide evidence that the genus Paranannizziopsis is widespread in wild snakes, with cases being identified in Louisiana (USA), Minnesota (USA), Virginia (USA), and British Columbia (Canada). Phylogenetic analyses conducted on multiple loci of the fungal strains we isolated identified P. australasiensis in Louisiana and Virginia; the remaining strains from Minnesota and British Columbia did not cluster with any of the described species of Paranannizziopsis, although the strains from British Columbia appear to represent a single lineage. Finally, we designed a pan-Paranannizziopsis real-time PCR assay targeting the internal transcribed spacer region 2. This assay successfully detected DNA of all described species of Paranannizziopsis and the two potentially novel taxa isolated in this study and did not cross-react with closely related fungi or other fungi commonly found on the skin of snakes. The assay was 100% sensitive and specific when screening clinical (skin tissue or skin swab) samples, although full determination of the assay's performance will require additional follow up due to the small number of clinical samples (n = 14 from 11 snakes) available for testing in our study. Nonetheless, the PCR assay can provide an important tool in further investigating the prevalence, distribution, and host range of Paranannizziopsis spp. and facilitate more rapid diagnosis of Paranannizziopsis spp. infections that are otherwise difficult to differentiate from other dermatomycoses.
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Affiliation(s)
- Jeffrey M. Lorch
- U.S. Geological Survey – National Wildlife Health Center, Madison, WI, United States
| | - Megan E. Winzeler
- U.S. Geological Survey – National Wildlife Health Center, Madison, WI, United States
| | - Julia S. Lankton
- U.S. Geological Survey – National Wildlife Health Center, Madison, WI, United States
| | - Stephen Raverty
- Animal Health Centre, Ministry of Agriculture, Abbotsford, BC, Canada
| | - Heindrich N. Snyman
- Animal Health Laboratory – Kemptville, University of Guelph, Kemptville, ON, Canada
| | - Helen Schwantje
- Wildlife and Habitat Branch, Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Nanaimo, BC, Canada
| | - Caeley Thacker
- Wildlife and Habitat Branch, Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Nanaimo, BC, Canada
| | - Susan Knowles
- U.S. Geological Survey – National Wildlife Health Center, Madison, WI, United States
| | - Hugh Y. Cai
- Animal Health Laboratory, Laboratory Services Division, University of Guelph, Guelph, ON, Canada
| | - Daniel A. Grear
- U.S. Geological Survey – National Wildlife Health Center, Madison, WI, United States
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19
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Barragan EM, Hoskins TD, Allmon EB, McQuigg JL, Hamilton MT, Christian EN, Coogan GSM, Searle CL, Choi YJ, Lee LS, Hoverman JT, Sepúlveda MS. Toxicities of Legacy and Current-Use PFAS in an Anuran: Do Larval Exposures Influence Responses to a Terrestrial Pathogen Challenge? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19180-19189. [PMID: 37962853 DOI: 10.1021/acs.est.3c03191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Legacy polyfluoroalkyl substances (PFAS) [perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA)] are being replaced by various other fluorinated compounds, such as hexafluoropropylene oxide dimer acid (GenX). These alternatives are thought to be less bioaccumulative and, therefore, less toxic than legacy PFAS. Contaminant exposures occur concurrently with exposure to natural stressors, including the fungal pathogen Batrachocytrium dendrobatidis (Bd). Despite evidence that other pollutants can increase the adverse effects of Bd on anurans, no studies have examined the interactive effects of Bd and PFAS. This study tested the growth and developmental effects of PFOS, PFOA, and GenX on gray treefrog (Hyla versicolor) tadpoles, followed by a Bd challenge after metamorphosis. Despite PFAS exposure only occurring during the larval stage, carry-over effects on growth were observed post metamorphosis. Further, PFAS interacted with Bd exposure to influence growth; Bd-exposed animals had significantly shorter SVL [snout-vent length (mm)] with significantly increased body condition, among other time-dependent effects. Our data suggest that larval exposure to PFAS can continue to impact growth in the juvenile stage after exposure has ended. Contrary to predictions, GenX affected terrestrial performance more consistently than its legacy congener, PFOA. Given the role of Bd in amphibian declines, further investigation of interactions of PFAS with Bd and other environmentally relevant pathogens is warranted.
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Affiliation(s)
- Evelyn M Barragan
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Tyler D Hoskins
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Elizabeth B Allmon
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jessica L McQuigg
- Department of Biology, Drew University, Madison, New Jersey 07940, United States
| | - Matthew T Hamilton
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Erin N Christian
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Grace S M Coogan
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Catherine L Searle
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Youn Jeong Choi
- Agronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Linda S Lee
- Agronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jason T Hoverman
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Maria S Sepúlveda
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
- Sustainability Research Center and PhD in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Santiago 7550196, Chile
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20
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Carvalho T, Si C, Clemons RA, Faust E, James TY. Amphibian Hymenochirus boettgeri as an experimental model for infection studies with the chytrid fungus Batrachochytrium dendrobatidis. Virulence 2023; 14:2270252. [PMID: 37823610 PMCID: PMC10614710 DOI: 10.1080/21505594.2023.2270252] [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: 07/03/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023] Open
Abstract
Model organisms are crucial in research as they can provide key insights applicable to other species. This study proposes the use of the amphibian species Hymenochirus boettgeri, widely available through the aquarium trade, as a model organism for the study of chytridiomycosis, a disease caused by the fungus Batrachochytrium dendrobatidis (Bd) and linked to amphibian decline and extinction globally. Currently, no model organisms are used in the study of chytridiomycosis, particularly because of the lack of availability and nonstandardized methods. Thus, laboratories around the world use wild local species to conduct Bd infection experiments, which prevents comparisons between studies and reduces reproducibility. Here, we performed a series of Bd infection assays that showed that H. boettgeri has a dose- and genotype-dependent response, can generalize previous findings on virulence estimates in other species, and can generate reproducible results in replicated experimental conditions. We also provided valuable information regarding H. boettgeri husbandry, including care, housing, reproduction, and heat treatment to eliminate previous Bd infections. Together, our results indicate that H. boettgeri is a powerful and low-ecological-impact system for studying Bd pathogenicity and virulence.
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Affiliation(s)
- Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Catherine Si
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Rebecca A. Clemons
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Evelyn Faust
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Timothy Y. James
- Department of Ecology and Evolutionary Biology, University of Michigan Herbarium, Ann Arbor, MI, USA
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21
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Sun D, Herath J, Zhou S, Ellepola G, Meegaskumbura M. Associations of Batrachochytrium dendrobatidis with skin bacteria and fungi on Asian amphibian hosts. ISME COMMUNICATIONS 2023; 3:123. [PMID: 37993728 PMCID: PMC10665332 DOI: 10.1038/s43705-023-00332-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/24/2023]
Abstract
Amphibian skin harbors microorganisms that are associated with the fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes chytridiomycosis, one of the most significant wildlife diseases known. This pathogen originated in Asia, where diverse Bd lineages exist; hence, native amphibian hosts have co-existed with Bd over long time periods. Determining the nuances of this co-existence is crucial for understanding the prevalence and spread of Bd from a microbial context. However, associations of Bd with the natural skin microbiome remain poorly understood for Asian hosts, especially in relation to skin-associated fungi. We used 16 S rRNA and fungal internal transcribed spacer (ITS) gene sequencing to characterize the skin microbiome of four native Asian amphibian species and examined the relationships between Bd infection and their skin bacterial and fungal communities; we also analyzed the correlates of the putative anti-Bd bacteria. We show that both skin bacterial and fungal community structure and composition had significant associations with infection status (Bd presence/absence) and infection intensity (frequency of Bd sequence reads). We also found that the putative anti-Bd bacterial richness was correlated with Bd infection status and infection intensity, and observed that the relative abundance of anti-Bd bacteria roughly correspond with changes in both Bd prevalence and mean infection intensity in populations. Additionally, the microbial co-occurrence network of infected frogs was significantly different from that of uninfected frogs that were characterized by more keystone nodes (connectors) and larger proportions in correlations between bacteria, suggesting stronger inter-module bacterial interactions. These results indicate that the mutual effects between Bd and skin-associated microbiome, including the interplay between bacteria and fungi, might vary with Bd infection in susceptible amphibian species. This knowledge will help in understanding the dynamics of Bd from a microbial perspective, potentially contributing to mitigate chytridiomycosis in other regions of the world.
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Affiliation(s)
- Dan Sun
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
| | - Jayampathi Herath
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
- School of Biomedical Sciences, International Institute of Health Sciences (IIHS), No 704 Negombo Rd, Welisara, 71722, Sri Lanka
| | - Shipeng Zhou
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
| | - Gajaba Ellepola
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
- Department of Zoology, Faculty of Science, University of Peradeniya, Peradeniya, KY20400, Sri Lanka
| | - Madhava Meegaskumbura
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China.
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22
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Forrest MJ, Halstead BJ, Grear DA, Kleeman PM, Todd BD, Miano OJ, Urquhart KD. KEEPING THE HEAT ON: WEIGHTED SURVEILLANCE FOR CHYTRID FUNGUS (BATRACHOCHYTRIUM DENDROBATIDIS) IN DIXIE VALLEY TOADS (ANAXYRUS [= BUFO] WILLIAMSI). J Wildl Dis 2023; 59:557-568. [PMID: 37486870 DOI: 10.7589/jwd-d-22-00049] [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: 04/21/2022] [Accepted: 03/09/2023] [Indexed: 07/26/2023]
Abstract
Introduced fungal pathogens have caused declines and extinctions of naïve wildlife populations across vertebrate classes. Consequences of introduced pathogens to hosts with small ranges might be especially severe because of limited redundancy to rescue populations and lower abundance that may limit the resilience of populations to perturbations like disease introduction. As a complement to biosecurity measures to prevent the spread of pathogens, surveillance programs may enable early detection of pathogens, when management actions to limit the effects of pathogens on naïve hosts might be most beneficial. We analyzed surveillance data for the endangered and narrowly endemic Dixie Valley toad (Anaxyrus [= Bufo] williamsi) from two time periods (2011-2014 and 2019-2021) to estimate the minimum detectable prevalence of the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd). We assessed if detection efficiency could be improved by using samples from both Dixie Valley toads and co-occurring introduced American bullfrogs (Lithobates catesbeianus) and literature-derived surveillance weights. We further evaluated a weighted surveillance design to increase the efficiency of surveillance efforts for Bd within the toad's small (<6 km2) range. We found that monitoring adult and larval American bullfrogs would probably detect Bd more efficiently than monitoring Dixie Valley toads alone. Given that no Bd was detected, minimum detectable prevalence of Bd was <3% in 2011-2014, and <5% (Dixie Valley toads only) and <10% (American bullfrogs only) in 2019-2021. Optimal management for Bd depends on the mechanisms underlying its apparent absence from the range of Dixie Valley toads, but a balanced surveillance scheme that includes sampling American bullfrogs to increase the likelihood of detecting Bd, and adult Dixie Valley toads to ensure broad spatial coverage where American bullfrogs do not occur, would probably result in efficient surveillance, which might permit timely management of Bd if it is detected.
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Affiliation(s)
- Matthew J Forrest
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
- Co-primary authors
| | - Brian J Halstead
- US Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, California 95620, USA
- Co-primary authors
| | - Daniel A Grear
- US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, Wisconsin 53711, USA
| | - Patrick M Kleeman
- US Geological Survey, Western Ecological Research Center, Point Reyes Field Station, 1 Bear Valley Road, Point Reyes Station, California 94956, USA
| | - Brian D Todd
- Department of Wildlife, Fish, and Conservation Biology, University of California-Davis, One Shields Avenue, Davis, California 95616, USA
| | - Oliver J Miano
- Department of Wildlife, Fish, and Conservation Biology, University of California-Davis, One Shields Avenue, Davis, California 95616, USA
| | - Kris D Urquhart
- Nevada Department of Wildlife, 380 West B Street, Fallon, Nevada 89406, USA
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23
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McMahon TA, Nordheim CL, Detmering SE, Johnson PTJ, Rohr JR, Civitello DJ. Pseudacris regilla metamorphs acquire resistance to Batrachochytrium dendrobatidis after exposure to the killed fungus. DISEASES OF AQUATIC ORGANISMS 2023; 155:193-198. [PMID: 37767886 DOI: 10.3354/dao03753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
The pathogenic fungus Batrachochytrium dendrobatidis (Bd) is associated with drastic global amphibian declines. Prophylactic exposure to killed zoospores and the soluble chemicals they produce (Bd metabolites) can induce acquired resistance to Bd in adult Cuban treefrogs Osteopilus septentrionalis. Here, we exposed metamorphic frogs of a second species, the Pacific chorus frog Pseudacris regilla, to one of 2 prophylactic treatments prior to live Bd exposures: killed Bd zoospores with metabolites, killed zoospores alone, or a water control. Prior exposure to killed Bd zoospores with metabolites reduced Bd infection intensity in metamorphic Pacific chorus frogs by 60.4% compared to control frogs. Interestingly, Bd intensity in metamorphs previously exposed to killed zoospores alone did not differ in magnitude relative to the control metamorphs, nor to those treated with killed zoospores plus metabolites. Previous work indicated that Bd metabolites alone can induce acquired resistance in tadpoles, and so these findings together indicate that it is possible that the soluble Bd metabolites may contain immunomodulatory components that drive this resistance phenotype. Our results expand the generality of this prophylaxis work by identifying a second amphibian species (Pacific chorus frog) and an additional amphibian life stage (metamorphic frog) that can acquire resistance to Bd after metabolite exposure. This work increases hopes that a Bd-metabolite prophylaxis might be widely effective across amphibian species and life stages.
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Affiliation(s)
- Taegan A McMahon
- Connecticut College, Department of Biology, New London, Connecticut 06320, USA
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24
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Carvalho T, Medina D, P Ribeiro L, Rodriguez D, Jenkinson TS, Becker CG, Toledo LF, Hite JL. Coinfection with chytrid genotypes drives divergent infection dynamics reflecting regional distribution patterns. Commun Biol 2023; 6:941. [PMID: 37709833 PMCID: PMC10502024 DOI: 10.1038/s42003-023-05314-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 09/01/2023] [Indexed: 09/16/2023] Open
Abstract
By altering the abundance, diversity, and distribution of species-and their pathogens-globalization may inadvertently select for more virulent pathogens. In Brazil's Atlantic Forest, a hotspot of amphibian biodiversity, the global amphibian trade has facilitated the co-occurrence of previously isolated enzootic and panzootic lineages of the pathogenic amphibian-chytrid (Batrachochytrium dendrobatidis, 'Bd') and generated new virulent recombinant genotypes ('hybrids'). Epidemiological data indicate that amphibian declines are most severe in hybrid zones, suggesting that coinfections are causing more severe infections or selecting for higher virulence. We investigated how coinfections involving these genotypes shapes virulence and transmission. Overall, coinfection favored the more virulent and competitively superior panzootic genotype, despite dampening its transmission potential and overall virulence. However, for the least virulent and least competitive genotype, coinfection increased both overall virulence and transmission. Thus, by integrating experimental and epidemiological data, our results provide mechanistic insight into how globalization can select for, and propel, the emergence of introduced hypervirulent lineages, such as the globally distributed panzootic lineage of Bd.
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Affiliation(s)
- Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil.
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Daniel Medina
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil
- Sistema Nacional de Investigación, SENACYT, Building 205, City of Knowledge, Clayton, Panama, Republic of Panama
- Department of Biology, and Center for Infectious Disease Dynamics, One Health Microbiome Center, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Luisa P Ribeiro
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil
| | - David Rodriguez
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA
| | - Thomas S Jenkinson
- Department of Biological Sciences, California State University-East Bay, Hayward, CA, 94542, USA
| | - C Guilherme Becker
- Department of Biology, and Center for Infectious Disease Dynamics, One Health Microbiome Center, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil
| | - Jessica L Hite
- School of Veterinary Medicine, Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
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25
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Marini D, Di Nicola MR, Crocchianti V, Notomista T, Iversen D, Coppari L, Di Criscio M, Brouard V, Dorne JLCM, Rüegg J, Marenzoni ML. Pilot survey reveals ophidiomycosis in dice snakes Natrix tessellata from Lake Garda, Italy. Vet Res Commun 2023; 47:1707-1719. [PMID: 37118129 PMCID: PMC10485108 DOI: 10.1007/s11259-023-10129-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/20/2023] [Indexed: 04/30/2023]
Abstract
Ophidiomycosis is an emerging infectious disease caused by the fungus Ophidiomyces ophidiicola (Oo). To date, Oo presence or associated disease condition has been recorded in wild and/or captive snakes from North America, Europe, Asia and Australia, but the data is still scarce outside the Nearctic. Although Italy is a country with a high snake biodiversity in the European panorama, and animals with clinical signs compatible with Oo infection have been documented, to date no investigations have reported the disease in the wild. Therefore, a pilot survey for the Italian territory was performed in conjunction with setting up a complete diagnostic workflow including SYBR Green-based real-time PCR assay for the detection of Oo genomic and mitochondrial DNA combined with histopathology of scale clips. Oo presence was investigated in 17 wild snake specimens from four different species. Four snakes were sampled in a targeted location where the mycosis was suspected via citizen science communications (i.e. North of the Lake Garda), whereas other ophidians were collected following opportunistic sampling. Oo genomic and mitochondrial DNA were detected and sequenced from all four Lake Garda Natrix tessellata, including three juveniles with macroscopic signs such as discolouration and skin crusts. From histopathological examination of scale clips, the three young positive individuals exhibited ulceration, inflammation and intralesional hyphae consistent with Oo infection, and two of them also showed the presence of arthroconidial tufts and solitary cylindrical arthrospores, allowing "Ophidiomycosis and Oo shedder" categorisation. For the remaining snake samples, the real-time PCR tested negative for Oo. This pilot survey permitted to localise for the first time Oo infection in free-ranging ophidians from Italy. Ophidiomycosis from Lake Garda highlights the need to increase sampling efforts in this area as well as in other northern Italian lakes to assess the occurrence of the pathogen, possible risk factors of the infection, its impact on host population fitness and the disease ecology of Oo in European snakes.
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Affiliation(s)
- Daniele Marini
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18A, Uppsala, 75236, Sweden.
- Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia, 06126, Italy.
| | - Matteo R Di Nicola
- Unit of Dermatology, IRCCS San Raffaele Hospital, Via Olgettina 60, Milan, 20132, Italy
- Asociación Herpetológica Española, Apartado de correos 191, Leganés, Madrid, 28911, Spain
| | - Veronica Crocchianti
- Service d'Anatomie Pathologique, VetAgro Sup, Campus Vétérinaire, 1 Avenue Bourgelat, Marcy l'Etoile, 69280, France
| | | | | | - Luca Coppari
- Studio Naturalistico Hyla s.r.l, Via Baroncino, 11, Tuoro sul Trasimeno, PG, 06069, Italy
| | - Michela Di Criscio
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18A, Uppsala, 75236, Sweden
| | - Vanessa Brouard
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18A, Uppsala, 75236, Sweden
| | - Jean-Lou C M Dorne
- Methodology and Scientific Support Unit, European Food Safety Authority (EFSA), Via Carlo Magno 1A, Parma, 43126, Italy
| | - Joëlle Rüegg
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18A, Uppsala, 75236, Sweden
| | - Maria Luisa Marenzoni
- Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, Perugia, 06126, Italy
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26
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Miller AJ, Gass J, Jo MC, Bishop L, Petereit J, Woodhams DC, Voyles J. Towards the generation of gnotobiotic larvae as a tool to investigate the influence of the microbiome on the development of the amphibian immune system. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220125. [PMID: 37305911 PMCID: PMC10258664 DOI: 10.1098/rstb.2022.0125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/28/2022] [Indexed: 06/13/2023] Open
Abstract
The immune equilibrium model suggests that exposure to microbes during early life primes immune responses for pathogen exposure later in life. While recent studies using a range of gnotobiotic (germ-free) model organisms offer support for this theory, we currently lack a tractable model system for investigating the influence of the microbiome on immune system development. Here, we used an amphibian species (Xenopus laevis) to investigate the importance of the microbiome in larval development and susceptibility to infectious disease later in life. We found that experimental reductions of the microbiome during embryonic and larval stages effectively reduced microbial richness, diversity and altered community composition in tadpoles prior to metamorphosis. In addition, our antimicrobial treatments resulted in few negative effects on larval development, body condition, or survival to metamorphosis. However, contrary to our predictions, our antimicrobial treatments did not alter susceptibility to the lethal fungal pathogen Batrachochytrium dendrobatidis (Bd) in the adult life stage. While our treatments to reduce the microbiome during early development did not play a critical role in determining susceptibility to disease caused by Bd in X. laevis, they nevertheless indicate that developing a gnotobiotic amphibian model system may be highly useful for future immunological investigations. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
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Affiliation(s)
| | - Jordan Gass
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Myung Chul Jo
- Environmental Health and Safety, University of Nevada, Reno, NV 89557, USA
| | - Lucas Bishop
- Nevada Bioinformatics Center, University of Nevada, Reno, NV 89557, USA
| | - Juli Petereit
- Nevada Bioinformatics Center, University of Nevada, Reno, NV 89557, USA
| | | | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, NV 89557, USA
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Hollanders M, Grogan LF, McCallum HI, Brannelly LA, Newell DA. Limited impact of chytridiomycosis on juvenile frogs in a recovered species. Oecologia 2023:10.1007/s00442-023-05406-w. [PMID: 37349661 DOI: 10.1007/s00442-023-05406-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 06/12/2023] [Indexed: 06/24/2023]
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused catastrophic frog declines on several continents, but disease outcome is mediated by a number of factors. Host life stage is an important consideration and many studies have highlighted the vulnerability of recently metamorphosed or juvenile frogs compared to adults. The majority of these studies have taken place in a laboratory setting, and there is a general paucity of longitudinal field studies investigating the influence of life stage on disease outcome. In this study, we assessed the effect of endemic Bd on juvenile Mixophyes fleayi (Fleay's barred frog) in subtropical eastern Australian rainforest. Using photographic mark-recapture, we made 386 captures of 116 individuals and investigated the effect of Bd infection intensity on the apparent mortality rates of frogs using a multievent model correcting for infection state misclassification. We found that neither Bd infection status nor infection intensity predicted mortality in juvenile frogs, counter to the expectation that early life stages are more vulnerable to disease, despite average high infection prevalence (0.35, 95% HDPI [0.14, 0.52]). Additionally, we found that observed infection prevalence and intensity were somewhat lower for juveniles than adults. Our results indicate that in this Bd-recovered species, the realized impacts of chytridiomycosis on juveniles were apparently low, likely resulting in high recruitment contributing to population stability. We highlight the importance of investigating factors relating to disease outcome in a field setting and make recommendations for future studies.
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Affiliation(s)
- Matthijs Hollanders
- Faculty of Science and Engineering, Southern Cross University, Lismore, NSW, Australia.
| | - Laura F Grogan
- Centre for Planetary Health and Food Security, and School of Environment and Science, Griffith University, Southport, QLD, Australia
| | - Hamish I McCallum
- Centre for Planetary Health and Food Security, and School of Environment and Science, Griffith University, Southport, QLD, Australia
| | - Laura A Brannelly
- Veterinary BioSciences, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, VIC, Australia
| | - David A Newell
- Faculty of Science and Engineering, Southern Cross University, Lismore, NSW, Australia
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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. FRONTIERS IN CONSERVATION SCIENCE 2023. [DOI: 10.3389/fcosc.2023.1069490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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McDonald CA, Becker CG, Lambertini C, Toledo LF, Haddad CFB, Zamudio KR. Host immune responses to enzootic and invasive pathogen lineages vary in magnitude, timing, and efficacy. Mol Ecol 2023; 32:2252-2270. [PMID: 36799008 DOI: 10.1111/mec.16890] [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: 08/12/2022] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Infectious diseases of wildlife continue to pose a threat to biodiversity worldwide, yet pathogens are far from uniform in virulence or host disease outcome. Within the same pathogen species, virulence can vary considerably depending on strain or lineage, in turn eliciting variable host responses. One pathogen that has caused extensive biodiversity loss is the amphibian-killing fungus, Batrachochytrium dendrobatidis (Bd), which is comprised of a globally widespread hypervirulent lineage (Bd-GPL), and multiple geographically restricted, enzootic lineages. Whereas host immunogenomic responses to Bd-GPL have been characterized in a number of amphibian species, immunogenomic responses to geographically restricted, enzootic Bd lineages are less clear. To examine lineage-specific host immune responses to Bd, we exposed a species of pumpkin toadlet, Brachycephalus pitanga, which is endemic to Brazil's Southern Atlantic Forest, to either the Bd-GPL or the enzootic Bd-Asia-2/Brazil (hereafter Bd-Brazil) lineage. Using temporal samples from early, mid, and late infection stages, we quantified functional immunogenomic responses over the course of infection using differential gene expression tests and coexpression network analyses. Host immune responses varied significantly with Bd lineage. Relative to controls, toadlet responses to Bd-Brazil were weak at early infection (25 genes significantly differentially expressed), peaked by mid-stage infection (414 genes), and were nearly fully resolved by late-stage infection (nine genes). In contrast, responses to Bd-GPL were magnified and delayed; toadlets significantly differentially expressed 111 genes early, 87 genes at mid-stage infection, and 726 genes by late-stage infection relative to controls. Given that infection intensity did not vary between mid- and late-stage disease in either Bd-Brazil or Bd-GPL treatments, this suggests that pumpkin toadlets may be at least partially tolerant to the enzootic Bd-Brazil lineage. In contrast, late-stage immune activation against Bd-GPL was consistent with immune dysregulation previously observed in other species. Our results demonstrate that both the timing of immune response and the particular immune pathways activated are specific to Bd lineage. Within regions where multiple Bd lineages co-occur, and given continued global Bd movement, these differential host responses may influence not only individual disease outcome, but transmission dynamics at the population and community levels.
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Affiliation(s)
- Coby A McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - C Guilherme Becker
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia Unicamp, Campinas, São Paulo, Brazil
| | - L Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia Unicamp, Campinas, São Paulo, Brazil
| | - Célio F B Haddad
- Departamento de Biodiversidade e Centro de Aquicultura (CAUNESP), Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, Brazil
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA.,Department of Integrative Biology, The University of Texas at Austin, Austin, Texas, USA
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Kaganer AW, Ossiboff RJ, Keith NI, Schuler KL, Comizzoli P, Hare MP, Fleischer RC, Gratwicke B, Bunting EM. Immune priming prior to pathogen exposure sheds light on the relationship between host, microbiome and pathogen in disease. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220810. [PMID: 36756057 PMCID: PMC9890126 DOI: 10.1098/rsos.220810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 01/04/2023] [Indexed: 06/18/2023]
Abstract
Dynamic interactions between host, pathogen and host-associated microbiome dictate infection outcomes. Pathogens including Batrachochytrium dendrobatidis (Bd) threaten global biodiversity, but conservation efforts are hindered by limited understanding of amphibian host, Bd and microbiome interactions. We conducted a vaccination and infection experiment using Eastern hellbender salamanders (Cryptobranchus alleganiensis alleganiensis) challenged with Bd to observe infection, skin microbial communities and gene expression of host skin, pathogen and microbiome throughout the experiment. Most animals survived high Bd loads regardless of their vaccination status and vaccination did not affect pathogen load, but host gene expression differed based on vaccination. Oral vaccination (exposure to killed Bd) stimulated immune gene upregulation while topically and sham-vaccinated animals did not significantly upregulate immune genes. In early infection, topically vaccinated animals upregulated immune genes but orally and sham-vaccinated animals downregulated immune genes. Bd increased pathogenicity-associated gene expression in late infection when Bd loads were highest. The microbiome was altered by Bd, but there was no correlation between anti-Bd microbe abundance or richness and pathogen burden. Our observations suggest that hellbenders initially generate a vigorous immune response to Bd, which is ineffective at controlling disease and is subsequently modulated. Interactions with antifungal skin microbiota did not influence disease progression.
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Affiliation(s)
- Alyssa W. Kaganer
- Department of Natural Resources and the Environment, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
| | - Robert J. Ossiboff
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Nicole I. Keith
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Biology Department, Hamilton College, Clinton, NY, 13323, USA
| | - Krysten L. Schuler
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Pierre Comizzoli
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
| | - Matthew P. Hare
- Department of Natural Resources and the Environment, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA
| | - Robert C. Fleischer
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Front Royal, VA, 22630, USA
| | - Elizabeth M. Bunting
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
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31
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Hollanders M, Grogan LF, Nock CJ, McCallum HI, Newell DA. Recovered frog populations coexist with endemic Batrachochytrium dendrobatidis despite load-dependent mortality. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2724. [PMID: 36054297 PMCID: PMC10078584 DOI: 10.1002/eap.2724] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/15/2022] [Accepted: 06/22/2022] [Indexed: 05/15/2023]
Abstract
Novel infectious diseases, particularly those caused by fungal pathogens, pose considerable risks to global biodiversity. The amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has demonstrated the scale of the threat, having caused the greatest recorded loss of vertebrate biodiversity attributable to a pathogen. Despite catastrophic declines on several continents, many affected species have experienced population recoveries after epidemics. However, the potential ongoing threat of endemic Bd in these recovered or recovering populations is still poorly understood. We investigated the threat of endemic Bd to frog populations that recovered after initial precipitous declines, focusing on the endangered rainforest frog Mixophyes fleayi. We conducted extensive field surveys over 4 years at three independent sites in eastern Australia. First, we compared Bd infection prevalence and infection intensities within frog communities to reveal species-specific infection patterns. Then, we analyzed mark-recapture data of M. fleayi to estimate the impact of Bd infection intensity on apparent mortality rates and Bd infection dynamics. We found that M. fleayi had lower infection intensities than sympatric frogs across the three sites, and cleared infections at higher rates than they gained infections throughout the study period. By incorporating time-varying individual infection intensities, we show that healthy M. fleayi populations persist despite increased apparent mortality associated with infrequent high Bd loads. Infection dynamics were influenced by environmental conditions, with Bd prevalence, infection intensity, and rates of gaining infection associated with lower temperatures and increased rainfall. However, mortality remained constant year-round despite these fluctuations in Bd infections, suggesting major mortality events did not occur over the study period. Together, our results demonstrate that while Bd is still a potential threat to recovered populations of M. fleayi, high rates of clearing infections and generally low average infection loads likely minimize mortality caused by Bd. Our results are consistent with pathogen resistance contributing to the coexistence of M. fleayi with endemic Bd. We emphasize the importance of incorporating infection intensity into disease models rather than infection status alone. Similar population and infection dynamics likely exist within other recovered amphibian-Bd systems around the globe, promising longer-term persistence in the face of endemic chytridiomycosis.
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Affiliation(s)
- Matthijs Hollanders
- Faculty of Science and EngineeringSouthern Cross UniversityLismoreNew South WalesAustralia
| | - Laura F. Grogan
- Centre for Planetary Health and Food Security, School of Environment and ScienceGriffith UniversityGold CoastQueenslandAustralia
| | - Catherine J. Nock
- Faculty of Science and EngineeringSouthern Cross UniversityLismoreNew South WalesAustralia
| | - Hamish I. McCallum
- Centre for Planetary Health and Food Security, School of Environment and ScienceGriffith UniversityGold CoastQueenslandAustralia
| | - David A. Newell
- Faculty of Science and EngineeringSouthern Cross UniversityLismoreNew South WalesAustralia
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32
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Greenspan SE, Peloso P, Fuentes-González JA, Bletz M, Lyra ML, Machado IF, Martins RA, Medina D, Moura-Campos D, Neely WJ, Preuss J, Sturaro MJ, Vaz RI, Navas CA, Toledo LF, Tozetti AM, Vences M, Woodhams DC, Haddad CFB, Pienaar J, Becker CG. Low microbiome diversity in threatened amphibians from two biodiversity hotspots. Anim Microbiome 2022; 4:69. [PMID: 36582011 PMCID: PMC9801548 DOI: 10.1186/s42523-022-00220-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 12/13/2022] [Indexed: 12/31/2022] Open
Abstract
Microbial diversity positively influences community resilience of the host microbiome. However, extinction risk factors such as habitat specialization, narrow environmental tolerances, and exposure to anthropogenic disturbance may homogenize host-associated microbial communities critical for stress responses including disease defense. In a dataset containing 43 threatened and 90 non-threatened amphibian species across two biodiversity hotspots (Brazil's Atlantic Forest and Madagascar), we found that threatened host species carried lower skin bacterial diversity, after accounting for key environmental and host factors. The consistency of our findings across continents suggests the broad scale at which low bacteriome diversity may compromise pathogen defenses in species already burdened with the threat of extinction.
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Affiliation(s)
- Sasha E. Greenspan
- grid.411015.00000 0001 0727 7545Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487 USA
| | - Pedro Peloso
- grid.452671.30000 0001 2175 1274Programa de Pós Gradução em Zoologia, Universidade Federal do Pará/Museu Paraense Emílio Goeldi, Belém, Pará 66077-530 Brazil ,Instituto Boitatá de Etnobiologia e Conservação da Fauna, Goiânia, Goiás 74085-480 Brazil
| | - Jesualdo A. Fuentes-González
- grid.65456.340000 0001 2110 1845The Department of Biology and the Institute of Environment, Florida International University, Miami, FL 33199 USA
| | - Molly Bletz
- grid.266685.90000 0004 0386 3207Department of Biology, University of Massachusetts Boston, Boston, MA 02125 USA
| | - Mariana L. Lyra
- grid.410543.70000 0001 2188 478XDepartment of Biodiversity and Aquaculture Center (CAUNESP), Universidade Estadual Paulista, Rio Claro, São Paulo 13506-900 Brazil
| | - Ibere F. Machado
- Instituto Boitatá de Etnobiologia e Conservação da Fauna, Goiânia, Goiás 74085-480 Brazil
| | - Renato A. Martins
- grid.411247.50000 0001 2163 588XPrograma de Pós-Graduação em Conservação da Fauna, Universidade Federal de São Carlos, São Carlos, São Paulo 13565-905 Brazil
| | - Daniel Medina
- Sistema Nacional de Investigación, SENACYT; City of Knowledge, Clayton, Panama, Republic of Panama ,grid.29857.310000 0001 2097 4281Department of Biology, The Pennsylvania State University, University Park, PA 16803 USA
| | - Diego Moura-Campos
- grid.411087.b0000 0001 0723 2494Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo 13083-862 Brazil ,grid.1001.00000 0001 2180 7477Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, 2601 Australia
| | - Wesley J. Neely
- grid.411015.00000 0001 0727 7545Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487 USA
| | - Jackson Preuss
- grid.412292.e0000 0004 0417 7532Departamento de Ciências da Vida, Universidade do Oeste de Santa Catarina, São Miguel Do Oeste, Santa Catarina 89900-000 Brazil
| | - Marcelo J. Sturaro
- grid.411249.b0000 0001 0514 7202Departamento de Ecologia e Biologia Evolutiva, Universidade Federal de São Paulo, Diadema, São Paulo 09972-270 Brazil
| | - Renata I. Vaz
- grid.11899.380000 0004 1937 0722Departamento de Fisiologia Geral, Instituto de Biociencias, Universidade de São Paulo, São Paulo, São Paulo 05508-090 Brazil
| | - Carlos A. Navas
- grid.11899.380000 0004 1937 0722Departamento de Fisiologia Geral, Instituto de Biociencias, Universidade de São Paulo, São Paulo, São Paulo 05508-090 Brazil
| | - Luís Felipe Toledo
- grid.411087.b0000 0001 0723 2494Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo 13083-862 Brazil
| | - Alexandro M. Tozetti
- grid.412302.60000 0001 1882 7290Programa de Pos-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, Rio Grande Do Sul 93022-750 Brazil
| | - Miguel Vences
- grid.6738.a0000 0001 1090 0254Zoological Institute, Braunschweig University of Technology, Mendelssohnstr. 4, Brunswick, Germany
| | - Douglas C. Woodhams
- grid.266685.90000 0004 0386 3207Department of Biology, University of Massachusetts Boston, Boston, MA 02125 USA
| | - Célio F. B. Haddad
- grid.410543.70000 0001 2188 478XDepartment of Biodiversity and Aquaculture Center (CAUNESP), Universidade Estadual Paulista, Rio Claro, São Paulo 13506-900 Brazil
| | - Jason Pienaar
- grid.65456.340000 0001 2110 1845The Department of Biology and the Institute of Environment, Florida International University, Miami, FL 33199 USA
| | - C. Guilherme Becker
- grid.29857.310000 0001 2097 4281Department of Biology, The Pennsylvania State University, University Park, PA 16803 USA
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Strachinis I, Marschang RE, Lymberakis P, Karagianni KM, Azmanis P. Infectious disease threats to amphibians in Greece: new localities positive for Batrachochytrium dendrobatidis. DISEASES OF AQUATIC ORGANISMS 2022; 152:127-138. [PMID: 36519684 DOI: 10.3354/dao03712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In the early 2000s, numerous cases of European amphibian population declines and mass die-offs started to emerge. Investigating those events led to the discovery that wild European amphibians were confronted with grave disease threats caused by introduced pathogens, namely the amphibian and the salamander chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal) and ranaviruses. In Greece, Bd was previously documented among wild amphibian populations in 2 different locations and 3 different species. However, no disease-related mass declines or mortality events have been reported. In this work, we build upon previous findings with new, subsequently obtained data, resulting in a 225-sample dataset of 14 species from 17 different locations throughout Greece, in order to examine the occurrence status of all 3 pathogens responsible for emerging infectious diseases in European amphibians. No positive samples for Bsal or ranavirus were recorded in any location. We confirmed the presence of Bd in 4 more localities and in 4 more species, including 1 urodelan (Macedonian crested newt Triturus macedonicus) and 1 introduced anuran (American bullfrog Lithobates catesbeianus). All insular localities were negative for Bd, except for Crete, where Bd was identified in 2 different locations. Again, no mass declines or die-offs were recorded in any Bd-positive area or elsewhere. However, given the persistence of Bd across Greece over the past ~20 yr, monitoring efforts should continue, and ideally be further expanded.
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Affiliation(s)
- Ilias Strachinis
- Department of Genetics, Development and Molecular Biology, School of Biology, Faculty of Natural Sciences, Aristotle University of Thessaloniki, 54636, Greece
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Lambertini C, Ernetti JR, Missassi AFR, Jorge RF, da Silva Leite D, Lima AP, Toledo LF. Chytrid fungus in amphibians from the lowland Brazilian Amazon. DISEASES OF AQUATIC ORGANISMS 2022; 152:115-125. [PMID: 36519683 DOI: 10.3354/dao03709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Infectious diseases are one of the main threats to biodiversity. The fungus Batrachochytrium dendrobatidis (Bd) is associated with several amphibian losses around the globe, and environmental conditions may dictate the success of pathogen spread. The Brazilian Amazon has been considered climatically unsuitable for chytrid fungus, but additional information on Bd dynamics in this ecoregion is still lacking. We sampled 462 amphibians (449 anurans, 4 caudatans and 9 caecilians), representing 57 species from the Brazilian Amazon, and quantified Bd infections using qPCR. We tested whether abiotic variables predicted the risk of Bd infections, and tested for relationships between biotic variables and Bd. Finally, we experimentally tested the effects of Bd strains CLFT 156 and CLFT 102 (from the southern and northern Atlantic Forest, respectively) on Atelopus manauensis. We detected higher Bd prevalence than those previously reported for the Brazilian Amazon, and positive individuals in all 3 orders of amphibians sampled. Both biotic and abiotic predictors were related to prevalence, and no variable explained infection load. Moreover, we detected higher Bd prevalence in forested than open areas, while the host's reproductive biology was not a factor. We detected higher mortality in the experimental group infected with CLFT 156, probably because this strain was isolated from a region characterized by discrepant climatic conditions (latitudinally more distant) when compared with the host's sampling site in Amazon. The lowland Brazilian Amazon is still underexplored and future studies targeting all amphibian orders are essential to better understand Bd infection dynamics in this region.
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Affiliation(s)
- Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo 13083-862, Brazil
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Bolom‐Huet R, Pineda E, Andrade‐Torres A, Díaz‐Fleischer F, Muñoz AL, Galindo‐González J. Chytrid prevalence and infection intensity in treefrogs from three environments with different degrees of conservation in Mexico. Biotropica 2022. [DOI: 10.1111/btp.13186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- René Bolom‐Huet
- Centro de Investigaciones en Ciencias Biológicas Aplicadas Universidad Autónoma del Estado de México Toluca Estado de México Mexico
- Universidad Veracruzana – Instituto de Biotecnología y Ecología Aplicada (INBIOTECA) Xalapa, Veracruz Mexico
| | - Eduardo Pineda
- Instituto de Ecologia – Red de Biología y Conservación de Vertebrados Xalapa, Veracruz Mexico
| | - Antonio Andrade‐Torres
- Universidad Veracruzana – Instituto de Biotecnología y Ecología Aplicada (INBIOTECA) Xalapa, Veracruz Mexico
| | - Francisco Díaz‐Fleischer
- Universidad Veracruzana – Instituto de Biotecnología y Ecología Aplicada (INBIOTECA) Xalapa, Veracruz Mexico
| | - Antonio L. Muñoz
- ECOSUR – Conservación de la Biodiversidad San Cristobal de las Casas, Chiapas Mexico
| | - Jorge Galindo‐González
- Universidad Veracruzana – Instituto de Biotecnología y Ecología Aplicada (INBIOTECA) Xalapa, Veracruz Mexico
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36
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Adams AJ, Bushell J, Grasso RL. To treat or not to treat? Experimental pathogen exposure, treatment, and release of a threatened amphibian. Ecosphere 2022. [DOI: 10.1002/ecs2.4294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Andrea J. Adams
- Resources Management and Science Division Yosemite National Park El Portal California USA
- Earth Research Institute University of California Santa Barbara California USA
| | | | - Robert L. Grasso
- Resources Management and Science Division Yosemite National Park El Portal California USA
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37
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Hollanders M, Royle JA. Know what you don't know: Embracing state uncertainty in disease‐structured multistate models. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Matthijs Hollanders
- Faculty of Science and Engineering Southern Cross University Lismore New South Wales Australia
| | - J. Andrew Royle
- U.S. Geological Survey, Patuxent Wildlife Research Center Laurel Maryland USA
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38
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Hulting KA, Mason SD, Story CM, Keller GS. Wetland cohesion is associated with increased probability of infection by the amphibian chytrid fungus Batrachochytrium dendrobatidis. DISEASES OF AQUATIC ORGANISMS 2022; 151:97-109. [PMID: 36226838 DOI: 10.3354/dao03692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) poses a substantial threat to amphibian populations. Understanding the landscape conditions that facilitate Bd transmission and persistence is crucial for predicting Bd trends in amphibian populations. Here, we investigated the interactions between land use, wetland connectivity, and Bd occurrence and infection intensity. In northeastern Massachusetts, we sampled Pseudacris crucifer, Lithobates sylvaticus, L. clamitans, and L. pipiens from 24 sites. We found an overall 30.6% Bd prevalence at our sites, with prevalence differing among species. Bd occurrence increased with wetland-patch cohesion, potentially due to microclimate shifts from decreased forest or changes in host movement. Bd infection intensity was not mediated by landscape context. Overall, our results highlight the importance of landscape structure for Bd dynamics, suggesting that certain landscapes may facilitate transmission and harbor Bd more than others. To mitigate the impacts of Bd on amphibian populations, conservation efforts should account for interactions between Bd and landscape variables.
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Affiliation(s)
- Katherine A Hulting
- Landscape Ecology Lab, Department of Life, Health, and Physical Sciences, Gordon College, Wenham, MA 01984, USA
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39
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Basanta MD, Avila-Akerberg V, Byrne AQ, Castellanos-Morales G, González Martínez TM, Maldonado-López Y, Rosenblum EB, Suazo-Ortuño I, Parra Olea G, Rebollar EA. The fungal pathogen Batrachochytrium salamandrivorans is not detected in wild and captive amphibians from Mexico. PeerJ 2022; 10:e14117. [PMID: 36213512 PMCID: PMC9536319 DOI: 10.7717/peerj.14117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/04/2022] [Indexed: 01/21/2023] Open
Abstract
The recent emergence of the pathogen Batrachochytrium salamandrivorans (Bsal) is associated with rapid population declines of salamanders in Europe and its arrival to new areas could cause dramatic negative effects on other amphibian populations and species. Amphibian species, present in areas with high amphibian diversity such as Mexico, could be highly threatened due to the arrival of Bsal, particularly salamander species which are more vulnerable to chytridiomycosis caused by this pathogen. Thus, immediate surveillance is needed as a strategy to efficiently contend with this emerging infectious disease. In this study, we analyzed 490 wild and captive amphibians from 48 species across 76 sites in the North, Central, and South of Mexico to evaluate the presence of Bsal. Amphibians were sampled in sites with variable degrees of amphibian richness and suitability for Bsal according to previous studies. From the 76 sampling sites, 10 of them were located in areas with high amphibian richness and potential moderate to high Bsal habitat suitability. We did not detect Bsal in any of the samples, and no signs of the disease were observed in any individual at the time of sampling. Our results suggest that Bsal has not yet arrived at the sampled sites or could be at low prevalence within populations with low occurrence probability. This is the first study that evaluates the presence of Bsal in different regions and amphibian species in Mexico, which is the second most diverse country in salamander species in the world. We highlight the risk and the importance of continuing surveillance of Bsal in Mexico and discuss control strategies to avoid the introduction and spread of Bsal in the country.
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Affiliation(s)
- M. Delia Basanta
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico,Facultad de Ciencias, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, Mexico,Department of Biology, University of Nevada Reno, Reno, Nevada, United States of America
| | - Victor Avila-Akerberg
- Instituto de Ciencias Agropecuarias y Rurales, Universidad Autónoma del Estado de México, Toluca, Estado de México, Mexico
| | - Allison Q. Byrne
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, United States of America
| | - Gabriela Castellanos-Morales
- Departamento de Conservación de la Biodiversidad, Colegio de la Frontera Sur Unidad, Villahermosa, Tabasco, México
| | | | - Yurixhi Maldonado-López
- CONACYT-Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Erica Bree Rosenblum
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, United States of America
| | - Ireri Suazo-Ortuño
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Gabriela Parra Olea
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Ciudad de México, Mexico
| | - Eria A. Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
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40
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Neely WJ, Greenspan SE, Stahl LM, Heraghty SD, Marshall VM, Atkinson CL, Becker CG. Habitat Disturbance Linked with Host Microbiome Dispersion and Bd Dynamics in Temperate Amphibians. MICROBIAL ECOLOGY 2022; 84:901-910. [PMID: 34671826 DOI: 10.1007/s00248-021-01897-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 10/08/2021] [Indexed: 06/13/2023]
Abstract
Anthropogenic habitat disturbances can dramatically alter ecological community interactions, including host-pathogen dynamics. Recent work has highlighted the potential for habitat disturbances to alter host-associated microbial communities, but the associations between anthropogenic disturbance, host microbiomes, and pathogens are unresolved. Amphibian skin microbial communities are particularly responsive to factors like temperature, physiochemistry, pathogen infection, and environmental microbial reservoirs. Through a field survey on wild populations of Acris crepitans (Hylidae) and Lithobates catesbeianus (Ranidae), we assessed the effects of habitat disturbance and connectivity on environmental bacterial reservoirs, Batrachochytrium dendrobatidis (Bd) infection, and skin microbiome composition. We found higher measures of microbiome dispersion (a measure of community variability) in A. crepitans from more disturbed ponds, supporting the hypothesis that disturbance increases stochasticity in biological communities. We also found that habitat disturbance limited microbiome similarity between locations for both species, suggesting greater isolation of bacterial assemblages in more disturbed areas. Higher disturbance was associated with lower Bd prevalence for A. crepitans, which could signify suboptimal microclimates for Bd in disturbed habitats. Combined, our findings show that reduced microbiome stability stemming from habitat disturbance could compromise population health, even in the absence of pathogenic infection.
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Affiliation(s)
- Wesley J Neely
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA.
| | - Sasha E Greenspan
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Leigha M Stahl
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Sam D Heraghty
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Vanessa M Marshall
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Carla L Atkinson
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - C Guilherme Becker
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
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41
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Fu M, Waldman B. Novel chytrid pathogen variants and the global amphibian pet trade. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2022; 36:e13938. [PMID: 35561039 DOI: 10.1111/cobi.13938] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 02/25/2022] [Indexed: 06/15/2023]
Abstract
Global wildlife trade spreads emerging infectious diseases that threaten biodiversity. The amphibian chytrid pathogen Batrachochytrium dendrobatidis (Bd) has caused population declines and species extinctions worldwide except in Asia. Fire-bellied toads (Bombina orientalis), exported in large numbers from Asia, are tolerant of Bd and carry hypervirulent ancestral chytrid BdAsia-1 variants. We assayed the virulence of a new isolate of BdAsia-1 on the model Australasian frog host Litoria caerulea. Infected individuals (n = 15) all showed rapid disease progression culminating in death, whereas sham-inoculated individuals (n = 10) presented no clinical signs of disease and all survived (log rank test, χ2 = 15.6, df = 1, p < 0.0001). The virulence of the new isolate of BdAsia-1 is comparable to the one we assayed previously (χ2 = 0.0, df = 1, p = 0.91). Internationally traded wildlife, even when they appear healthy, can carry hypervirulent variants of pathogens. Once new pathogen variants escape into the environment, native species that have had no opportunity to evolve resistance to them may perish. Our study suggests that hypervirulent pathogens are being spread by the international pet trade. Notifiable wildlife diseases attributable to locally endemic pathogens often fail to generate conservation concern so are rarely subject to border surveillance or import controls. Because of the danger novel variants pose, national border control agencies need to implement disease screening and quarantine protocols to ensure the safety of their endemic fauna.
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Affiliation(s)
- Minjie Fu
- School of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Bruce Waldman
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma, USA
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42
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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] [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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43
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Basanta MD, Anaya‐Morales SL, Martínez‐Ugalde E, González Martínez TM, Ávila‐Akerberg VD, Trejo MV, Rebollar EA. Metamorphosis and seasonality are major determinants of chytrid infection in a paedomorphic salamander. Anim Conserv 2022. [DOI: 10.1111/acv.12824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. D. Basanta
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
- Department of Biology University of Nevada Reno Reno NV USA
| | - S. L. Anaya‐Morales
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
| | - E. Martínez‐Ugalde
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
| | - T. M. González Martínez
- Facultad de Ciencias Universidad Nacional Autónoma de México, Ciudad Universitaria Ciudad de México Mexico
| | - V. D. Ávila‐Akerberg
- Instituto de Ciencias Agropecuarias y Rurales Universidad Autónoma del Estado de México Toluca Estado de México Mexico
| | - M. V. Trejo
- Facultad de Ciencias Universidad Nacional Autónoma de México, Ciudad Universitaria Ciudad de México Mexico
| | - E. A. Rebollar
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
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44
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Cook K, Pope K, Cummings A, Piovia‐Scott J. In situ treatment of juvenile frogs for disease can reverse population declines. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Kimberly Cook
- School of Biological Sciences Washington State University Vancouver WA USA
| | - Karen Pope
- Pacific Southwest Research Station United States Forest Service California USA
| | - Adam Cummings
- Pacific Southwest Research Station United States Forest Service California USA
| | - Jonah Piovia‐Scott
- School of Biological Sciences Washington State University Vancouver WA USA
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45
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Le Sage EH, Ohmer MEB, LaBumbard BC, Altman KA, Reinert LK, Bednark JG, Bletz MC, Inman B, Lindauer A, McDonnell NB, Parker SK, Skerlec SM, Wantman T, Rollins‐Smith LA, Woodhams DC, Voyles J, Richards‐Zawacki CL. Localized carry‐over effects of pond drying on survival, growth, and pathogen defenses in amphibians. Ecosphere 2022. [DOI: 10.1002/ecs2.4224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Emily H. Le Sage
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Michel E. B. Ohmer
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | | | - Karie A. Altman
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Laura K. Reinert
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Jeffery G. Bednark
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Molly C. Bletz
- Department of Biology University of Massachusetts Boston Massachusetts USA
| | - Brady Inman
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
- Department of Biology University of Massachusetts Boston Massachusetts USA
| | - Alexa Lindauer
- Department of Biology University of Nevada Reno Nevada USA
| | - Nina B. McDonnell
- Department of Biology University of Massachusetts Boston Massachusetts USA
| | - Sadie K. Parker
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Samantha M. Skerlec
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Trina Wantman
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Louise A. Rollins‐Smith
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
- Department of Biological Sciences Vanderbilt University Nashville Tennessee USA
- Department of Pediatrics Vanderbilt University School of Medicine Nashville Tennessee USA
| | | | - Jamie Voyles
- Department of Biology University of Nevada Reno Nevada USA
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46
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Comparative host-pathogen associations of Snake Fungal Disease in sympatric species of water snakes (Nerodia). Sci Rep 2022; 12:12303. [PMID: 35853982 PMCID: PMC9295108 DOI: 10.1038/s41598-022-16664-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 07/13/2022] [Indexed: 11/09/2022] Open
Abstract
The ascomycete fungus Ophidiomyces ophiodiicola (Oo) is the causative agent of ophidiomycosis (Snake Fungal Disease), which has been detected globally. However, surveillance efforts in the central U.S., specifically Texas, have been minimal. The threatened and rare Brazos water snake (Nerodia harteri harteri) is one of the most range restricted snakes in the U.S. and is sympatric with two wide-ranging congeners, Nerodia erythrogaster transversa and Nerodia rhombifer, in north central Texas; thus, providing an opportunity to test comparative host-pathogen associations in this system. To accomplish this, we surveyed a portion of the Brazos river drainage (~ 400 river km) over 29 months and tested 150 Nerodia individuals for the presence of Oo via quantitative PCR and recorded any potential signs of Oo infection. We found Oo was distributed across the entire range of N. h. harteri, Oo prevalence was 46% overall, and there was a significant association between Oo occurrence and signs of infection in our sample. Models indicated adults had a higher probability of Oo infection than juveniles and subadults, and adult N. h. harteri had a higher probability of infection than adult N. rhombifer but not higher than adult N. e. transversa. High Oo prevalence estimates (94.4%) in adult N. h. harteri has implications for their conservation and management owing to their patchy distribution, comparatively low genetic diversity, and threats from anthropogenic habitat modification.
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47
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Estrada A, Medina D, Gratwicke B, Ibáñez R, Belden LK. Body condition, skin bacterial communities and disease status: insights from the first release trial of the limosa harlequin frog,
Atelopus limosus. Proc Biol Sci 2022; 289:20220586. [PMID: 35858072 PMCID: PMC9277274 DOI: 10.1098/rspb.2022.0586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Many endangered amphibian species survive in captive breeding facilities, but there have been few attempts to reintroduce captive-born individuals to rebuild wild populations. We conducted a soft-release trial of limosa harlequin frogs,
Atelopus limosus,
which are highly susceptible to the amphibian chytrid fungus
Batrachochytrium dendrobatidis
(Bd), to understand changes associated with the transition from captivity to the wild. Specifically, we assessed changes in body condition, skin-associated bacterial communities and disease status after release. Frogs were housed individually in field mesocosms and monitored for 27 days. Body condition did not significantly change in the mesocosms, and was similar to, or higher than, that of wild conspecifics at day 27. The skin bacteria of captive-born frogs, based on 16S rRNA gene amplicons, became similar to that of wild conspecifics after 27 days in mesocosms. Prevalence of Bd in wild conspecifics was 13–27%, and 15% of the
A. limosus
in mesocosms became infected with Bd, but no mortality of infected frogs was observed. We conclude that mesocosms are suitable for systematically and repeatedly monitoring amphibians during release trials, and that body condition, the skin microbiome, and Bd status can all change within one month of placement of captive-born individuals back into the wild.
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Affiliation(s)
- Angie Estrada
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
| | - Daniel Medina
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
- Smithsonian Tropical Research Institute, Panama City, Panama
- Sistema Nacional de Investigación, SENACYT, Panama
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Roberto Ibáñez
- Smithsonian Tropical Research Institute, Panama City, Panama
- Sistema Nacional de Investigación, SENACYT, Panama
| | - Lisa K. Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
- Smithsonian Tropical Research Institute, Panama City, Panama
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Cortazar-Chinarro M, Meurling S, Schroyens L, Siljestam M, Richter-Boix A, Laurila A, Höglund J. Major Histocompatibility Complex Variation and Haplotype Associated Survival in Response to Experimental Infection of Two Bd-GPL Strains Along a Latitudinal Gradient. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.915271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
While both innate and adaptive immune system mechanisms have been implicated in resistance against the chytrid fungus Batrachochytrium dendrobatidis (Bd), studies on the role of specific MHC haplotypes on Bd infection are rare. Here, we studied variation in MHC Class IIB loci in the common toad Bufo bufo along a latitudinal gradient across Sweden. In general, Swedish toad populations had few MHC Class IIB haplotypes and MHC diversity declined from south (13 haplotypes) to the north (four haplotypes). The low diversity may compromise the ability of northern populations to fight emerging disease, such as Bd. In a laboratory experiment, we infected newly metamorphosed toads with two strains of the Global Pandemic Lineage of the fungus (Bd-GPL) and compared survival with sham controls. Bd-infected toads had lower survival compared to controls. Moreover, survival was dependent on the Bd-strain and northern toads had lower Bd-mediated survival than southern individuals. MHC diversity was lower in northern toads. All northern experimental animals were monomorphic for a single MHC haplotype, whereas we found seven different haplotypes in southern experimental animals. In southern toads, survival was dependent on both Bd-strain and MHC haplotype suggesting differential infection dynamics depending on both Bd-strain and host immune system characteristics.
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49
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Cramp RL, Ohmer MEB, Franklin CE. UV exposure causes energy trade-offs leading to increased chytrid fungus susceptibility in green tree frog larvae. CONSERVATION PHYSIOLOGY 2022; 10:coac038. [PMID: 35795017 PMCID: PMC9252104 DOI: 10.1093/conphys/coac038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/11/2022] [Accepted: 06/02/2022] [Indexed: 06/14/2023]
Abstract
Levels of ultraviolet (UV) radiation have increased in many parts of the world due to the anthropogenic destruction of the ozone layer. UV radiation is a potent immunosuppressant and can increase the susceptibility of animal hosts to pathogens. UV radiation can directly alter immune function via immunosuppression and photoimmunotolerance; however, UV may also influence pathogen defences by affecting the distribution of energy resources among competing physiological processes. Both defence against UV damage and repair of incurred damage, as well as the maintenance of immune defences and responding to an immune challenge, are energetically expensive. These competing demands for finite energy resources could trade off against one another, resulting in sub-optimal performance in one or both processes. We examined the potential for a disease-related energy trade-off in green tree frog (Litoria caerulea) larvae. Larvae were reared under high- or low-UV conditions for 12 weeks during which time we measured growth rates, metabolic rate and susceptibility to the amphibian fungal pathogen, Batrachochytrium dendrobatidis (Bd). We found that larvae exposed to high levels of UV radiation had higher rates of energy expenditure than those exposed to low UV levels; however, UV exposure did not affect growth rates or developmental timings. Larvae exposed to high UV radiation also experienced greater Bd infection rates and carried a higher infection burden than those not exposed to elevated UV radiation. We propose that the increased energetic costs of responding to UV radiation were traded off against immune defences to protect larval growth rates. These findings have important implications for the aetiology of some Bd-associated amphibian declines, particularly in montane environments where Bd infections are most severe and where UV levels are highest.
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Affiliation(s)
- Rebecca L Cramp
- Corresponding author: School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia. Tel: +61 7 3365 8539.
| | - Michel E B Ohmer
- Department of Biology, University of Mississippi, MS, 38677, USA
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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Rosa GM, Perez R, Richards LA, Richards‐Zawacki CL, Smilanich AM, Reinert LK, Rollins‐Smith LA, Wetzel DP, Voyles J. Seasonality of host immunity in a tropical disease system. Ecosphere 2022. [DOI: 10.1002/ecs2.4158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Gonçalo M. Rosa
- Department of Biology University of Nevada, Reno Reno Nevada USA
- Institute of Zoology Zoological Society of London London UK
- Centre for Ecology, Evolution and Environmental Changes Faculdade de Ciências da Universidade de Lisboa Lisbon Portugal
| | - Rachel Perez
- Department of Biology New Mexico Institute of Mining and Technology Socorro New Mexico USA
| | - Lora A. Richards
- Department of Biology University of Nevada, Reno Reno Nevada USA
| | | | | | - Laura K. Reinert
- Department of Pathology Microbiology and Immunology, Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Louise A. Rollins‐Smith
- Department of Pathology Microbiology and Immunology, Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Daniel P. Wetzel
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Jamie Voyles
- Department of Biology University of Nevada, Reno Reno Nevada USA
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