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Sun D, Ellepola G, Herath J, Meegaskumbura M. Ecological Barriers for an Amphibian Pathogen: A Narrow Ecological Niche for Batrachochytrium salamandrivorans in an Asian Chytrid Hotspot. J Fungi (Basel) 2023; 9:911. [PMID: 37755019 PMCID: PMC10532633 DOI: 10.3390/jof9090911] [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: 08/08/2023] [Revised: 09/02/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023] Open
Abstract
The chytrid fungal pathogens Batrachochytrium salamandrivorans (Bsal) and B. dendrobatidis (Bd) are driving amphibian extinctions and population declines worldwide. As their origins are believed to be in East/Southeast Asia, this region is crucial for understanding their ecology. However, Bsal screening is relatively limited in this region, particularly in hotspots where Bd lineage diversity is high. To address this gap, we conducted an extensive Bsal screening involving 1101 individuals from 36 amphibian species, spanning 17 natural locations and four captive facilities in the biodiversity-rich Guangxi Zhuang Autonomous Region (GAR). Our PCR assays yielded unexpected results, revealing the complete absence of Bsal in all tested samples including 51 individuals with Bd presence. To understand the potential distribution of Bsal, we created niche models, utilizing existing occurrence records from both Asia and Europe. These models estimated potential suitable habitats for Bsal largely in the northern and southwestern parts of the GAR. Although Bsal was absent in our samples, the niche models identified 10 study sites as being potentially suitable for this pathogen. Interestingly, out of these 10 sites, Bd was detected at 8. This suggests that Bsal and Bd could possibly co-exist in these habitats, if Bsal were present. Several factors seem to influence the distribution of Bsal in Asia, including variations in temperature, local caudate species diversity, elevation, and human population density. However, it is climate-related factors that hold the greatest significance, accounting for a notable 60% contribution. The models propose that the specific climatic conditions of arid regions, primarily seen in the GAR, play a major role in the distribution of Bsal. Considering the increased pathogenicity of Bsal at stable and cooler temperatures (10-15 °C), species-dependent variations, and the potential for seasonal Bd-Bsal interactions, we emphasize the importance of periodic monitoring for Bsal within its projected range in the GAR. Our study provides deeper insights into Bsal's ecological niche and the knowledge generated will facilitate conservation efforts in amphibian populations devastated by chytrid pathogens across 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 530000, China; (D.S.)
| | - Gajaba Ellepola
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530000, China; (D.S.)
- Department of Zoology, Faculty of Science, University of Peradeniya, Peradeniya, Kandy 20400, Sri Lanka
| | - Jayampathi Herath
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530000, China; (D.S.)
- School of Biomedical Sciences, International Institute of Health Sciences (IIHS), No. 704 Negombo Road, Welisara 71722, Sri Lanka
| | - Madhava Meegaskumbura
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530000, China; (D.S.)
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2
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Schilliger L, Paillusseau C, François C, Bonwitt J. Major Emerging Fungal Diseases of Reptiles and Amphibians. Pathogens 2023; 12:pathogens12030429. [PMID: 36986351 PMCID: PMC10053826 DOI: 10.3390/pathogens12030429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/16/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
Emerging infectious diseases (EIDs) are caused by pathogens that have undergone recent changes in terms of geographic spread, increasing incidence, or expanding host range. In this narrative review, we describe three important fungal EIDs with keratin trophism that are relevant to reptile and amphibian conservation and veterinary practice. Nannizziopsis spp. have been mainly described in saurians; infection results in thickened, discolored skin crusting, with eventual progression to deep tissues. Previously only reported in captive populations, it was first described in wild animals in Australia in 2020. Ophidiomyces ophidiicola (formely O. ophiodiicola) is only known to infect snakes; clinical signs include ulcerating lesions in the cranial, ventral, and pericloacal regions. It has been associated with mortality events in wild populations in North America. Batrachochytrium spp. cause ulceration, hyperkeratosis, and erythema in amphibians. They are a major cause of catastrophic amphibian declines worldwide. In general, infection and clinical course are determined by host-related characteristics (e.g., nutritional, metabolic, and immune status), pathogens (e.g., virulence and environmental survival), and environment (e.g., temperature, hygrometry, and water quality). The animal trade is thought to be an important cause of worldwide spread, with global modifications in temperature, hygrometry, and water quality further affecting fungal pathogenicity and host immune response.
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Affiliation(s)
- Lionel Schilliger
- Argos Veterinary Clinic of Paris Auteuil, 35 Rue Leconte de Lisle, 75016 Paris, France
- SpéNac Referral Center, 100 Boulevard de la Tour Maubourg, 75007 Paris, France
- Correspondence: ; Tel.: +33-188-616-831
| | - Clément Paillusseau
- Argos Veterinary Clinic of Paris Auteuil, 35 Rue Leconte de Lisle, 75016 Paris, France
- SpéNac Referral Center, 100 Boulevard de la Tour Maubourg, 75007 Paris, France
| | - Camille François
- Argos Veterinary Clinic of Paris Auteuil, 35 Rue Leconte de Lisle, 75016 Paris, France
- SpéNac Referral Center, 100 Boulevard de la Tour Maubourg, 75007 Paris, France
| | - Jesse Bonwitt
- Department of Anthropology, Durham University, South Rd., Durham DH1 3LE, UK
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3
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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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4
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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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5
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Cowgill M, Zink AG, Sparagon W, Yap TA, Sulaeman H, Koo MS, Vredenburg VT. Social Behavior, Community Composition, Pathogen Strain, and Host Symbionts Influence Fungal Disease Dynamics in Salamanders. Front Vet Sci 2021; 8:742288. [PMID: 34938792 PMCID: PMC8687744 DOI: 10.3389/fvets.2021.742288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/06/2021] [Indexed: 11/29/2022] Open
Abstract
The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), which can cause a fatal disease called chytridiomycosis, is implicated in the collapse of hundreds of host amphibian species. We describe chytridiomycosis dynamics in two co-occurring terrestrial salamander species, the Santa Lucia Mountains slender salamander, Batrachoseps luciae, and the arboreal salamander, Aneides lugubris. We (1) conduct a retrospective Bd-infection survey of specimens collected over the last century, (2) estimate present-day Bd infections in wild populations, (3) use generalized linear models (GLM) to identify biotic and abiotic correlates of infection risk, (4) investigate susceptibility of hosts exposed to Bd in laboratory trials, and (5) examine the ability of host skin bacteria to inhibit Bd in culture. Our historical survey of 2,866 specimens revealed that for most of the early 20th century (~1920–1969), Bd was not detected in either species. By the 1990s the proportion of infected specimens was 29 and 17% (B. luciae and A. lugubris, respectively), and in the 2010s it was 10 and 17%. This was similar to the number of infected samples from contemporary populations (2014–2015) at 10 and 18%. We found that both hosts experience signs of chytridiomycosis and suffered high Bd-caused mortality (88 and 71% for B. luciae and A. lugubris, respectively). Our GLM revealed that Bd-infection probability was positively correlated with intraspecific group size and proximity to heterospecifics but not to abiotic factors such as precipitation, minimum temperature, maximum temperature, mean temperature, and elevation, or to the size of the hosts. Finally, we found that both host species contain symbiotic skin-bacteria that inhibit growth of Bd in laboratory trials. Our results provide new evidence consistent with other studies showing a relatively recent Bd invasion of amphibian host populations in western North America and suggest that the spread of the pathogen may be enabled both through conspecific and heterospecific host interactions. Our results suggest that wildlife disease studies should assess host-pathogen dynamics that consider the interactions and effects of multiple hosts, as well as the historical context of pathogen invasion, establishment, and epizootic to enzootic transitions to better understand and predict disease dynamics.
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Affiliation(s)
- Mae Cowgill
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Andrew G Zink
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Wesley Sparagon
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, UUniversity of Hawai'i at Mānoa, HI, United States
| | - Tiffany A Yap
- Center for Biological Diversity, Oakland, CA, United States
| | - Hasan Sulaeman
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Michelle S Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, United States.,Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, United States
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6
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Woodhams DC, Madison JD, Bletz MC, McCartney J, LaBumbard BC, Whetstone R, McDonnell NB, Preissler K, Sabino-Pinto J, Piovia-Scott J. Responsible biosecurity and risk mitigation for laboratory research on emerging pathogens of amphibians. DISEASES OF AQUATIC ORGANISMS 2021; 147:141-148. [PMID: 34913442 DOI: 10.3354/dao03636] [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: 06/14/2023]
Abstract
The increasing study of emerging wildlife pathogens and a lack of policy or legislation regulating their translocation and use has heightened concerns about laboratory escape, species spillover, and subsequent epizootics among animal populations. Responsible self-regulation by research laboratories, in conjunction with institutional-level safeguards, has an important role in mitigating pathogen transmission and spillover, as well as potential interspecies pathogenesis. A model system in disease ecology that highlights these concerns and related amelioration efforts is research focused on amphibian emerging infectious diseases. Whereas laboratory escape of amphibian pathogens has not been reported and may be rare compared with introduction events from trade or human globalization, the threat that novel disease outbreaks with mass mortality effects pose to wild populations warrants thorough biosecurity measures to ensure containment and prevent spillover. Here, we present a case study of the laboratory biosecurity concerns for the emerging amphibian fungal pathogen Batrachochytrium salamandrivorans. We conclude that proactive biosecurity strategies are needed to integrate researcher and institutional oversight of aquatic wildlife pathogens generally, and we call for increased national and international policy and legislative enforcement. Furthermore, taking professional responsibility beyond current regulations is needed as development of legal guidance can be slow at national and international levels. We outline the need for annual laboratory risk assessments, comprehensive training for all laboratory personnel, and appropriate safeguards specific to pathogens under study. These strategies are critical for upholding the integrity and credibility of the scientific community and maintaining public support for research on wildlife diseases.
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Affiliation(s)
- Douglas C Woodhams
- Biology Department, University of Massachusetts Boston, Boston, MA 02125, USA
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7
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García‐Rodríguez A, Basanta MD, García‐Castillo MG, Zumbado‐Ulate H, Neam K, Rovito S, Searle CL, Parra‐Olea G. Anticipating the potential impacts of
Batrachochytrium salamandrivorans
on Neotropical salamander diversity. Biotropica 2021. [DOI: 10.1111/btp.13042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Adrián García‐Rodríguez
- Departamento de Zoología Instituto de Biología Universidad Nacional Autónoma de México Ciudad de México México
- BioInvasions, Global Change, Macroecology‐Group Department of Botany and Biodiversity Research University of Vienna Vienna Austria
| | - M. Delia Basanta
- Departamento de Zoología Instituto de Biología Universidad Nacional Autónoma de México Ciudad de México México
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos México
| | - Mirna G. García‐Castillo
- Universidad Politécnica de Huatusco Huatusco Veracruz México
- Facultad de Ciencias Biológicas y Agropecuarias Región: Orizaba–Córdoba Universidad Veracruzana Amatlán de los Reyes Veracruz México
| | | | - Kelsey Neam
- Global Wildlife Conservation Austin Texas USA
- Amphibian Specialist Group IUCN Species Survival Commission USA
| | - Sean Rovito
- Unidad de Genómica Avanzada (Langebio) CINVESTAV Irapuato México
| | - Catherine L. Searle
- Department of Biological Sciences Purdue University West Lafayette Indiana USA
| | - Gabriela Parra‐Olea
- Departamento de Zoología Instituto de Biología Universidad Nacional Autónoma de México Ciudad de México México
- Amphibian Specialist Group IUCN Species Survival Commission USA
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8
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Kelly M, Pasmans F, Muñoz JF, Shea TP, Carranza S, Cuomo CA, Martel A. Diversity, multifaceted evolution, and facultative saprotrophism in the European Batrachochytrium salamandrivorans epidemic. Nat Commun 2021; 12:6688. [PMID: 34795258 PMCID: PMC8602665 DOI: 10.1038/s41467-021-27005-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 10/28/2021] [Indexed: 01/06/2023] Open
Abstract
While emerging fungi threaten global biodiversity, the paucity of fungal genome assemblies impedes thoroughly characterizing epidemics and developing effective mitigation strategies. Here, we generate de novo genomic assemblies for six outbreaks of the emerging pathogen Batrachochytrium salamandrivorans (Bsal). We reveal the European epidemic currently damaging amphibian populations to comprise multiple, highly divergent lineages demonstrating isolate-specific adaptations and metabolic capacities. In particular, we show extensive gene family expansions and acquisitions, through a variety of evolutionary mechanisms, and an isolate-specific saprotrophic lifecycle. This finding both explains the chytrid's ability to divorce transmission from host density, producing Bsal's enigmatic host population declines, and is a key consideration in developing successful mitigation measures.
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Affiliation(s)
- Moira Kelly
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium.
| | - Frank Pasmans
- grid.5342.00000 0001 2069 7798Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - Jose F. Muñoz
- grid.66859.34Broad Institute of MIT and Harvard, Cambridge, 02142 MA USA
| | - Terrance P. Shea
- grid.66859.34Broad Institute of MIT and Harvard, Cambridge, 02142 MA USA
| | - Salvador Carranza
- grid.507636.10000 0004 0424 5398Institute of Evolutionary Biology (CSIC-UPF), 08003 Barcelona, Spain
| | - Christina A. Cuomo
- grid.66859.34Broad Institute of MIT and Harvard, Cambridge, 02142 MA USA
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium.
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9
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Bernard RF, Grant EHC. Rapid Assessment Indicates Context‐Dependent Mitigation for Amphibian Disease Risk. WILDLIFE SOC B 2021. [DOI: 10.1002/wsb.1198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Riley F. Bernard
- Department of Zoology and Physiology University of Wyoming Laramie WY 82071 USA
| | - Evan H. Campbell Grant
- United States Geological Survey, Eastern Ecological Science Center S. O. Conte Anadromous Fish Laboratory Turners Falls MA 01376 USA
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10
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Pereira KE, Woodley SK. Skin defenses of North American salamanders against a deadly salamander fungus. Anim Conserv 2021. [DOI: 10.1111/acv.12666] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- K. E. Pereira
- Department of Biological Sciences Duquesne University Pittsburgh PA USA
| | - S. K. Woodley
- Department of Biological Sciences Duquesne University Pittsburgh PA USA
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11
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Lastra González D, Baláž V, Chajma P, Vojar J. Surveying for Batrachochytrium salamandrivorans presence in Spanish captive collections of amphibians. DISEASES OF AQUATIC ORGANISMS 2020; 142:99-103. [PMID: 33269721 DOI: 10.3354/dao03535] [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: 06/12/2023]
Abstract
Batrachochytrium salamandrivorans (Bsal), a pathogenic fungus causing the fatal disease chytridiomycosis in amphibians, was likely introduced to Europe through the trade in pet salamanders from Asia and then escaped into wild populations. Among European countries, Spain has a large number of private breeders and keepers of pet salamanders, and cases of Bsal in wild and captive populations already have been confirmed there. However, surveillance for the pathogen in Spanish collections of amphibians is sparse. Therefore, assisted by private owners and breeders, we surveyed 10 amphibian collections and analysed a total of 317 samples for presence of Bsal. All of our analyses yielded negative results. However, this apparent lack of Bsal cases in captivity should not encourage relaxation of vigilance, quarantine efforts or good practices. Because amphibian collections represent highly dynamic environments (animals are coming in and out), the pathogen could easily be introduced into a collection by new individuals. Any case of Bsal infection in captive animals could lead to its further spread to wild populations of susceptible species, potentially decimating them, and thus should be prevented.
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Affiliation(s)
- D Lastra González
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Prague - Suchdol, Czech Republic
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12
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Instant killing of pathogenic chytrid fungi by disposable nitrile gloves prevents disease transmission between amphibians. PLoS One 2020; 15:e0241048. [PMID: 33119670 PMCID: PMC7595420 DOI: 10.1371/journal.pone.0241048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/07/2020] [Indexed: 12/03/2022] Open
Abstract
To prevent transmission of the pathogenic chytrid fungi Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), hygiene protocols prescribe the single use of disposable gloves for handling amphibians. We discovered that rinse water from nitrile gloves instantly kills 99% of Bd and Bsal zoospores. Transmission experiments using midwife toads (Alytes obstetricans) and Bd, and Alpine newts (Ichthyosaura alpestris) and Bsal, show that the use of the same pair of gloves for 2 subsequent individuals does not result in significant transmission of any chytrid fungus. In contrast, handling infected amphibians bare-handed caused transmission of Bsal in 4 out of 10 replicates, but did not result in transmission of Bd. Based on the manufacturer’s information, high resolution mass spectrometry (HRMS) and colorimetric tests, calcium lactate and calcium nitrate were identified as compounds with antifungal activity against both Bd and Bsal. These findings corroborate the importance of wearing gloves as an important sanitary measure in amphibian disease prevention. If the highly recommended single use of gloves is not possible, handling multiple post-metamorphic amphibians with the same pair of nitrile gloves should still be preferred above bare-handed manipulation.
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13
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Batrachochytrium salamandrivorans (Bsal) not detected in an intensive survey of wild North American amphibians. Sci Rep 2020; 10:13012. [PMID: 32747670 PMCID: PMC7400573 DOI: 10.1038/s41598-020-69486-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 05/22/2020] [Indexed: 11/22/2022] Open
Abstract
The salamander chytrid fungus (Batrachochytrium salamandrivorans [Bsal]) is causing massive mortality of salamanders in Europe. The potential for spread via international trade into North America and the high diversity of salamanders has catalyzed concern about Bsal in the U.S. Surveillance programs for invading pathogens must initially meet challenges that include low rates of occurrence on the landscape, low prevalence at a site, and imperfect detection of the diagnostic tests. We implemented a large-scale survey to determine if Bsal was present in North America designed to target taxa and localities where Bsal was determined highest risk to be present based on species susceptibility and geography. Our analysis included a Bayesian model to estimate the probability of occurrence of Bsal given our prior knowledge of the occurrence and prevalence of the pathogen. We failed to detect Bsal in any of 11,189 samples from 594 sites in 223 counties within 35 U.S. states and one site in Mexico. Our modeling indicates that Bsal is highly unlikely to occur within wild amphibians in the U.S. and suggests that the best proactive response is to continue mitigation efforts against the introduction and establishment of the disease and to develop plans to reduce impacts should Bsal establish.
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14
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Malagon DA, Melara LA, Prosper OF, Lenhart S, Carter ED, Fordyce JA, Peterson AC, Miller DL, Gray MJ. Host density and habitat structure influence host contact rates and Batrachochytrium salamandrivorans transmission. Sci Rep 2020; 10:5584. [PMID: 32221329 PMCID: PMC7101388 DOI: 10.1038/s41598-020-62351-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 03/11/2020] [Indexed: 12/22/2022] Open
Abstract
Batrachochytrium salamandrivorans (Bsal) is an emerging invasive pathogen that is highly pathogenic to salamander species. Modeling infection dynamics in this system can facilitate proactive efforts to mitigate this pathogen's impact on North American species. Given its widespread distribution and high abundance, the eastern newt (Notophthalmus viridescens) has the potential to significantly influence Bsal epidemiology. We designed experiments to 1) estimate contact rates given different host densities and habitat structure and 2) estimate the probability of transmission from infected to susceptible individuals. Using parameter estimates from data generated during these experiments, we modeled infection and disease outcomes for a population of newts using a system of differential equations. We found that host contact rates were density-dependent, and that adding habitat structure reduced contacts. The probability of Bsal transmission given contact between newts was very high (>90%) even at early stages of infection. Our simulations show rapid transmission of Bsal among individuals following pathogen introduction, with infection prevalence exceeding 90% within one month and >80% mortality of newts in three months. Estimates of basic reproductive rate (R0) of Bsal for eastern newts were 1.9 and 3.2 for complex and simple habitats, respectively. Although reducing host density and increasing habitat complexity might decrease transmission, these management strategies may be ineffective at stopping Bsal invasion in eastern newt populations due to this species’ hyper-susceptibility.
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Affiliation(s)
- Daniel A Malagon
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - Luis A Melara
- Department of Mathematics, Shippensburg University, Shippensburg, PA, 17257, USA
| | - Olivia F Prosper
- Department of Mathematics, University of Kentucky, Lexington, KY, 40506, USA.,Department of Mathematics, University of Tennessee, Knoxville, TN, 37996, USA
| | - Suzanne Lenhart
- Department of Mathematics, University of Tennessee, Knoxville, TN, 37996, USA
| | - Edward Davis Carter
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - J A Fordyce
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Anna C Peterson
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - Debra L Miller
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA.,Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, 37996, USA
| | - Matthew J Gray
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA.
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15
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Bates KA, Shelton JMG, Mercier VL, Hopkins KP, Harrison XA, Petrovan SO, Fisher MC. Captivity and Infection by the Fungal Pathogen Batrachochytrium salamandrivorans Perturb the Amphibian Skin Microbiome. Front Microbiol 2019; 10:1834. [PMID: 31507541 PMCID: PMC6716147 DOI: 10.3389/fmicb.2019.01834] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/25/2019] [Indexed: 12/13/2022] Open
Abstract
The emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal) is responsible for the catastrophic decline of European salamanders and poses a threat to amphibians globally. The amphibian skin microbiome can influence disease outcome for several host-pathogen systems, yet little is known of its role in Bsal infection. In addition, many experimental in-vivo amphibian disease studies to date have relied on specimens that have been kept in captivity for long periods without considering the influence of environment on the microbiome and how this may impact the host response to pathogen exposure. We characterized the impact of captivity and exposure to Bsal on the skin bacterial and fungal communities of two co-occurring European newt species, the smooth newt, Lissotriton vulgaris and the great-crested newt, Triturus cristatus. We show that captivity led to significant losses in bacterial and fungal diversity of amphibian skin, which may be indicative of a decline in microbe-mediated protection. We further demonstrate that in both L. vulgaris and T. cristatus, Bsal infection was associated with changes in the composition of skin bacterial communities with possible negative consequences to host health. Our findings advance current understanding of the role of host-associated microbiota in Bsal infection and highlight important considerations for ex-situ amphibian conservation programmes.
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Affiliation(s)
- Kieran A Bates
- Department of Zoology, University of Oxford, Oxford, United Kingdom.,Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom.,Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Jennifer M G Shelton
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
| | - Victoria L Mercier
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
| | - Kevin P Hopkins
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Xavier A Harrison
- Institute of Zoology, Zoological Society of London, London, United Kingdom.,College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Silviu O Petrovan
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Froglife, Peterborough, United Kingdom
| | - Matthew C Fisher
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
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16
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Apparent absence of Batrachochytrium salamandrivorans in wild urodeles in the United Kingdom. Sci Rep 2019; 9:2831. [PMID: 30862900 PMCID: PMC6414544 DOI: 10.1038/s41598-019-39338-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 01/18/2019] [Indexed: 11/09/2022] Open
Abstract
Whether an infectious disease threat to wildlife arises from pathogen introduction or the increased incidence of an already-present agent informs mitigation policy and actions. The prior absence of a pathogen can be difficult to establish, particularly in free-living wildlife. Subsequent to the epidemic emergence of the fungus, Batrachochytrium salamandrivorans (Bsal), in mainland Europe in 2010 and prior to its detection in captive amphibians in the United Kingdom (UK), we tested archived skin swabs using a Bsal-specific qPCR. These samples had been collected in 2011 from 2409 wild newts from ponds across the UK. All swabs were negative for Bsal. Bayesian hierarchical modelling suggests that Bsal was absent from, or present at very low levels in, these ponds at the time of sampling. Additionally, surveillance of newt mortality incidents, 2013-2017, failed to detect Bsal. As this pathogen has been shown to be widespread in British captive amphibian collections, there is an urgent need to raise awareness of the importance of effective biosecurity measures, especially amongst people with captive amphibians, to help minimise the risk of Bsal spreading to the wild. Continued and heightened wild amphibian disease surveillance is a priority to provide an early warning system for potential incursion events.
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17
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Basanta MD, Rebollar EA, Parra-Olea G. Potential risk of Batrachochytrium salamandrivorans in Mexico. PLoS One 2019; 14:e0211960. [PMID: 30753218 PMCID: PMC6372179 DOI: 10.1371/journal.pone.0211960] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/24/2019] [Indexed: 02/07/2023] Open
Abstract
The recent decline in populations of European salamanders caused by the chytrid fungus Batrachochytrium salamandrivorans (Bsal) has generated worldwide concern, as it is a major threat to amphibians. Evaluation of the areas most suitable for the establishment of Bsal combined with analysis of the distribution of salamander species could be used to generate and implement biosecurity measures and protect biodiversity at sites with high salamander diversity. In this study, we identified the areas most suitable for the establishment of Bsal in Mexico. Mexico has the second-highest salamander species diversity in the world; thus, we identified areas moderately to highly suitable for the establishment of Bsal with high salamander diversity as potential hotspots for surveillance. Central and Southern Mexico were identified as high-risk zones, with 13 hotspots where 30% of Mexican salamander species occur, including range-restricted species and endangered species. We propose that these hotspots should be thoroughly monitored for the presence of Bsal to prevent the spread of the pathogen if it is introduced to the country.
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Affiliation(s)
- M. Delia Basanta
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, AP, Tercer Circuito Exterior s/ n, Ciudad Universitaria, Ciudad de México, México
- Posgrado en Ciencias Biológicas, Unidad de Posgrado, Edificio A, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, C.P., Ciudad de México, México
| | - Eria A. Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Gabriela Parra-Olea
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, AP, Tercer Circuito Exterior s/ n, Ciudad Universitaria, Ciudad de México, México
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18
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Fitzpatrick LD, Pasmans F, Martel A, Cunningham AA. Epidemiological tracing of Batrachochytrium salamandrivorans identifies widespread infection and associated mortalities in private amphibian collections. Sci Rep 2018; 8:13845. [PMID: 30218076 PMCID: PMC6138723 DOI: 10.1038/s41598-018-31800-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 08/23/2018] [Indexed: 12/17/2022] Open
Abstract
The amphibian chytrid fungus Batrachochytrium salamandrivorans (Bsal) infects newts and salamanders (urodele amphibians), in which it can cause fatal disease. This pathogen has caused dramatic fire salamander population declines in Belgium, the Netherlands and Germany since its discovery in 2010. Thought to be native to Asia, it has been hypothesised that Bsal was introduced to Europe with the importation of infected amphibians for the commercial pet trade. Following the discovery of Bsal in captive amphibians in the United Kingdom in 2015, we used contact-tracing to identify epidemiologically-linked private amphibian collections in Western Europe. Of 16 linked collections identified, animals were tested from 11 and urodeles tested positive for Bsal in seven, including the identification of the pathogen in Spain for the first time. Mortality of Bsal-positive individuals was observed in five collections. Our results indicate that Bsal is likely widespread within the private amphibian trade, at least in Europe. These findings are important for informing policy regarding Bsal control strategies.
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Affiliation(s)
- Liam D Fitzpatrick
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Andrew A Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
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19
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Asymptomatic infection of the fungal pathogen Batrachochytrium salamandrivorans in captivity. Sci Rep 2018; 8:11767. [PMID: 30082745 PMCID: PMC6078946 DOI: 10.1038/s41598-018-30240-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 07/14/2018] [Indexed: 12/30/2022] Open
Abstract
One of the most important factors driving amphibian declines worldwide is the infectious disease, chytridiomycosis. Two fungi have been associated with this disease, Batrachochytrium dendrobatidis and B. salamandrivorans (Bsal). The latter has recently driven Salamandra salamandra populations to extirpation in parts of the Netherlands, and Belgium, and potentially also in Germany. Bsal has been detected in the pet trade, which has been hypothesized to be the pathway by which it reached Europe, and which may continuously contribute to its spread. In the present study, 918 amphibians belonging to 20 captive collections in Germany and Sweden were sampled to explore the extent of Bsal presence in captivity. The fungus was detected by quantitative Polymerase Chain Reaction (qPCR) in ten collections, nine of which lacked clinical symptoms. 23 positives were confirmed by independent processing of duplicate swabs, which were analysed in a separate laboratory, and/or by sequencing ITS and 28 S gene segments. These asymptomatic positives highlight the possibility of Bsal being widespread in captive collections, and is of high conservation concern. This finding may increase the likelihood of the pathogen being introduced from captivity into the wild, and calls for according biosecurity measures. The detection of Bsal-positive alive specimens of the hyper-susceptible fire salamander could indicate the existence of a less aggressive Bsal variant or the importance of environmental conditions for infection progression.
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20
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Standish I, Leis E, Schmitz N, Credico J, Erickson S, Bailey J, Kerby J, Phillips K, Lewis T. Optimizing, validating, and field testing a multiplex qPCR for the detection of amphibian pathogens. DISEASES OF AQUATIC ORGANISMS 2018; 129:1-13. [PMID: 29916388 DOI: 10.3354/dao03230] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Amphibian populations worldwide are facing numerous threats, including the emergence and spread of infectious diseases. In the past 2 decades, Batrachochytrium dendrobatidis (Bd), a parasitic fungus, and a group of viruses comprising the genus Ranavirus have become widespread and resulted in mass mortality events and extirpations worldwide. In 2013, another novel fungus, B. salamandrivorans (Bsal), was attributed to dramatic declines in populations of fire salamander Salamandra salamandra in the Netherlands. Experimental infections demonstrated that Bsal is highly pathogenic to numerous salamander genera. In an effort to prevent the introduction of Bsal to North America, the US Fish and Wildlife Service (USFWS) listed 201 salamander species as injurious wildlife under the Lacey Act. To determine infection status and accurately assess amphibian health, the development of a sensitive and specific diagnostic assay was needed. We describe the optimization and validation of a multiplex quantitative polymerase chain reaction (qPCR) protocol for the simultaneous detection of Bd, Bsal, and frog virus 3-like ranaviruses. A synthetic genome template (gBlock®) containing the target genes from all 3 pathogens served as the positive control and allowed accurate quantification of pathogen genes. The assay was validated in the field using an established non-lethal swabbing technique to survey local amphibian populations throughout a range of habitats. This multiplex qPCR demonstrates high reproducibility, sensitivity, and was capable of detecting both Bd and ranavirus in numerous locations, species, and life stages. Bsal was not detected at any point during these sampling efforts.
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Affiliation(s)
- Isaac Standish
- US Fish and Wildlife Service, Midwest Fisheries Center, La Crosse Fish Health Center, Onalaska, WI 54650, USA
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21
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Cunningham AA, Daszak P, Wood JLN. One Health, emerging infectious diseases and wildlife: two decades of progress? Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0167. [PMID: 28584175 PMCID: PMC5468692 DOI: 10.1098/rstb.2016.0167] [Citation(s) in RCA: 256] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2017] [Indexed: 01/29/2023] Open
Abstract
Infectious diseases affect people, domestic animals and wildlife alike, with many pathogens being able to infect multiple species. Fifty years ago, following the wide-scale manufacture and use of antibiotics and vaccines, it seemed that the battle against infections was being won for the human population. Since then, however, and in addition to increasing antimicrobial resistance among bacterial pathogens, there has been an increase in the emergence of, mostly viral, zoonotic diseases from wildlife, sometimes causing fatal outbreaks of epidemic proportions. Concurrently, infectious disease has been identified as an increasing threat to wildlife conservation. A synthesis published in 2000 showed common anthropogenic drivers of disease threats to biodiversity and human health, including encroachment and destruction of wildlife habitat and the human-assisted spread of pathogens. Almost two decades later, the situation has not changed and, despite improved knowledge of the underlying causes, little has been done at the policy level to address these threats. For the sake of public health and wellbeing, human-kind needs to work better to conserve nature and preserve the ecosystem services, including disease regulation, that biodiversity provides while also understanding and mitigating activities which lead to disease emergence. We consider that holistic, One Health approaches to the management and mitigation of the risks of emerging infectious diseases have the greatest chance of success. This article is part of the themed issue ‘One Health for a changing world: zoonoses, ecosystems and human well-being’.
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Affiliation(s)
- Andrew A Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Peter Daszak
- Ecohealth Alliance, 460 West 34th Street, New York, NY 10001, USA
| | - James L N Wood
- Department of Veterinary Medicine, Disease Dynamics Unit, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
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22
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Yuan Z, Martel A, Wu J, Van Praet S, Canessa S, Pasmans F. Widespread occurrence of an emerging fungal pathogen in heavily traded Chinese urodelan species. Conserv Lett 2018. [DOI: 10.1111/conl.12436] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Zhiyong Yuan
- Key Laboratory for Forest Resources Conservation and Utilisation in the Southwest Mountains of China, Ministry of Education; Southwest Forestry University; Yunnan 650224 China
- Key Laboratory of Forest Disaster Warning and Control of Yunnan Province; Southwest Forestry University; Kunming Yunnan 650224 China
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine; Ghent University; Salisburylaan 133 Merelbeke 9820 Belgium
| | - Jun Wu
- Nanjing Institute of Environmental Sciences; Ministry of Environmental Protection of China; Nanjing Jiangsu 210042 China
| | - Sarah Van Praet
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine; Ghent University; Salisburylaan 133 Merelbeke 9820 Belgium
| | - Stefano Canessa
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine; Ghent University; Salisburylaan 133 Merelbeke 9820 Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine; Ghent University; Salisburylaan 133 Merelbeke 9820 Belgium
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23
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Thomas V, Blooi M, Van Rooij P, Van Praet S, Verbrugghe E, Grasselli E, Lukac M, Smith S, Pasmans F, Martel A. Recommendations on diagnostic tools for Batrachochytrium salamandrivorans. Transbound Emerg Dis 2018; 65:e478-e488. [PMID: 29341499 DOI: 10.1111/tbed.12787] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Indexed: 02/05/2023]
Abstract
Batrachochytrium salamandrivorans (Bsal) poses a major threat to amphibian, and more specifically caudata, diversity. Bsal is currently spreading through Europe, and mitigation measures aimed at stopping its spread and preventing its introduction into naïve environments are urgently needed. Screening for presence of Bsal and diagnosis of Bsal-induced disease in amphibians are essential core components of effective mitigation plans. Therefore, the aim of this study was to present an overview of all Bsal diagnostic tools together with their limitations and to suggest guidelines to allow uniform interpretation. Here, we investigate the use of different diagnostic tools in post-mortem detection of Bsal and whether competition between Bd and Bsal occurs in the species-specific Bd and Bsal duplex real-time PCR. We also investigate the diagnostic sensitivity, diagnostic specificity and reproducibility of the Bsal real-time PCR and show the use of immunohistochemistry in diagnosis of Bsal-induced chytridiomycosis in amphibian samples stored in formaldehyde. Additionally, we have drawn up guidelines for the use and interpretation of the different diagnostic tools for Bsal currently available, to facilitate standardization of execution and interpretation.
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Affiliation(s)
- V Thomas
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - M Blooi
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - P Van Rooij
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - S Van Praet
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - E Verbrugghe
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - E Grasselli
- Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, DISTAV, Universita di Genova, Genova, Italy
| | - M Lukac
- Department of Poultry Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - S Smith
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Austria
| | - F Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - A Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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24
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Yap TA, Nguyen NT, Serr M, Shepack A, Vredenburg VT. Batrachochytrium salamandrivorans and the Risk of a Second Amphibian Pandemic. ECOHEALTH 2017; 14:851-864. [PMID: 29147975 DOI: 10.1007/s10393-017-1278-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/07/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
Amphibians are experiencing devastating population declines globally. A major driver is chytridiomycosis, an emerging infectious disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Bd was described in 1999 and has been linked with declines since the 1970s, while Bsal is a more recently discovered pathogen that was described in 2013. It is hypothesized that Bsal originated in Asia and spread via international trade to Europe, where it has been linked to salamander die-offs. Trade in live amphibians thus represents a significant threat to global biodiversity in amphibians. We review the current state of knowledge regarding Bsal and describe the risk of Bsal spread. We discuss regional responses to Bsal and barriers that impede a rapid, coordinated global effort. The discovery of a second deadly emerging chytrid fungal pathogen in amphibians poses an opportunity for scientists, conservationists, and governments to improve global biosecurity and further protect humans and wildlife from a growing number of emerging infectious diseases.
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Affiliation(s)
- Tiffany A Yap
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Avenue, San Francisco, CA, 94132, USA.
- Museum of Vertebrate Zoology, University of California Berkeley, 3101 Valley Life Sciences Building, Berkeley, CA, 94720, USA.
| | - Natalie T Nguyen
- U.S. Geological Survey National Wildlife Health Center, 6006 Schroeder Rd., Madison, WI, 53711, USA
| | - Megan Serr
- Department of Biological Sciences, North Carolina State University, Thomas Hall, 1100 Brooks Avenue, Raleigh, NC, 27695, USA
| | - Alexander Shepack
- Zoology Department, Southern Illinois University Carbondale, 1125 Lincoln Drive, Carbondale, IL, 62901, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
- Museum of Vertebrate Zoology, University of California Berkeley, 3101 Valley Life Sciences Building, Berkeley, CA, 94720, USA
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25
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Klocke B, Becker M, Lewis J, Fleischer RC, Muletz-Wolz CR, Rockwood L, Aguirre AA, Gratwicke B. Batrachochytrium salamandrivorans not detected in U.S. survey of pet salamanders. Sci Rep 2017; 7:13132. [PMID: 29030586 PMCID: PMC5640657 DOI: 10.1038/s41598-017-13500-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 09/25/2017] [Indexed: 02/01/2023] Open
Abstract
We engaged pet salamander owners in the United States to screen their animals for two amphibian chytrid fungal pathogens Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). We provided pet owners with a sampling kit and instructional video to swab the skin of their animals. We received 639 salamander samples from 65 species by mail, and tested them for Bd and Bsal using qPCR. We detected Bd on 1.3% of salamanders (95% CI 0.0053–0.0267) and did not detect Bsal (95% CI 0.0000–0.0071). If Bsal is present in the U.S. population of pet salamanders, it occurs at a very low prevalence. The United States Fish and Wildlife Service listed 201 species of salamanders as “injurious wildlife” under the Lacey Act (18 U.S.C. § 42) on January 28, 2016, a precautionary action to prevent the introduction of Bsal to the U.S. through the importation of salamanders. This action reduced the number of salamanders imported to the U.S. from 2015 to 2016 by 98.4%. Our results indicate that continued precautions should be taken to prevent the introduction and establishment of Bsal in the U.S., which is a hotspot of salamander biodiversity.
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Affiliation(s)
- Blake Klocke
- Department of Environmental Science and Policy, George Mason University, Fairfax, Virginia, 22030, United States of America. .,Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, 20008, United States of America. .,Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, 20008, United States of America.
| | - Matthew Becker
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, 20008, United States of America.,Department of Biology and Chemistry, Liberty University, Lynchburg, Virginia, 24515, United States of America
| | - James Lewis
- Rainforest Trust, Warrenton, VA, 20187, United States of America
| | - Robert C Fleischer
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, 20008, United States of America
| | - Carly R Muletz-Wolz
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, 20008, United States of America
| | - Larry Rockwood
- Department of Environmental Science and Policy, George Mason University, Fairfax, Virginia, 22030, United States of America.,Department of Biology, George Mason University, Fairfax, Virginia, 22030, United States of America
| | - A Alonso Aguirre
- Department of Environmental Science and Policy, George Mason University, Fairfax, Virginia, 22030, United States of America
| | - Brian Gratwicke
- Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, 20008, United States of America
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26
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Van Rooij P, Pasmans F, Coen Y, Martel A. Efficacy of chemical disinfectants for the containment of the salamander chytrid fungus Batrachochytrium salamandrivorans. PLoS One 2017; 12:e0186269. [PMID: 29023562 PMCID: PMC5638399 DOI: 10.1371/journal.pone.0186269] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 09/28/2017] [Indexed: 12/11/2022] Open
Abstract
The recently emerged chytrid fungus Batrachochytrium salamandrivorans (Bsal) causes European salamander declines. Proper hygiene protocols including disinfection procedures are crucial to prevent disease transmission. Here, the efficacy of chemical disinfectants in killing Bsal was evaluated. At all tested conditions, Biocidal®, Chloramine-T®, Dettol medical®, Disolol®, ethanol, F10®, Hibiscrub®, potassium permanganate, Safe4®, sodium hypochlorite, and Virkon S®, were effective at killing Bsal. Concentrations of 5% sodium chloride or lower, 0.01% peracetic acid and 0.001–1% copper sulphate were inactive against Bsal. None of the conditions tested for hydrogen peroxide affected Bsal viability, while it did kill Batrachochytrium dendrobatidis (Bd). For Bsal, enzymatic breakdown of hydrogen peroxide by catalases and specific morphological features (clustering of sporangia, development of new sporangia within the original sporangium), were identified as fungal factors altering susceptibility to several of the disinfectants tested. Based on the in vitro results we recommend 1% Virkon S®, 4% sodium hypochlorite and 70% ethanol for disinfecting equipment in the field, lab or captive setting, with a minimal contact time of 5 minutes for 1% Virkon S® and 1 minute for the latter disinfectants. These conditions not only efficiently target Bsal, but also Bd and Ranavirus.
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Affiliation(s)
- Pascale Van Rooij
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Yanaika Coen
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- * E-mail:
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The Emerging Amphibian Fungal Disease, Chytridiomycosis: A Key Example of the Global Phenomenon of Wildlife Emerging Infectious Diseases. Microbiol Spectr 2017; 4. [PMID: 27337484 DOI: 10.1128/microbiolspec.ei10-0004-2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The spread of amphibian chytrid fungus, Batrachochytrium dendrobatidis, is associated with the emerging infectious wildlife disease chytridiomycosis. This fungus poses an overwhelming threat to global amphibian biodiversity and is contributing toward population declines and extinctions worldwide. Extremely low host-species specificity potentially threatens thousands of the 7,000+ amphibian species with infection, and hosts in additional classes of organisms have now also been identified, including crayfish and nematode worms.Soon after the discovery of B. dendrobatidis in 1999, it became apparent that this pathogen was already pandemic; dozens of countries and hundreds of amphibian species had already been exposed. The timeline of B. dendrobatidis's global emergence still remains a mystery, as does its point of origin. The reason why B. dendrobatidis seems to have only recently increased in virulence to catalyze this global disease event remains unknown, and despite 15 years of investigation, this wildlife pandemic continues primarily uncontrolled. Some disease treatments are effective on animals held in captivity, but there is currently no proven method to eradicate B. dendrobatidis from an affected habitat, nor have we been able to protect new regions from exposure despite knowledge of an approaching "wave" of B. dendrobatidis and ensuing disease.International spread of B. dendrobatidis is largely facilitated by the commercial trade in live amphibians. Chytridiomycosis was recently listed as a globally notifiable disease by the World Organization for Animal Health, but few countries, if any, have formally adopted recommended measures to control its spread. Wildlife diseases continue to emerge as a consequence of globalization, and greater effort is urgently needed to protect global health.
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Cunningham AA, Daszak P, Wood JLN. One Health, emerging infectious diseases and wildlife: two decades of progress? Philos Trans R Soc Lond B Biol Sci 2017. [DOI: 10.1098/rstb.2016.0167 https://doi.org/10.1098/rstb.2016.0167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Infectious diseases affect people, domestic animals and wildlife alike, with many pathogens being able to infect multiple species. Fifty years ago, following the wide-scale manufacture and use of antibiotics and vaccines, it seemed that the battle against infections was being won for the human population. Since then, however, and in addition to increasing antimicrobial resistance among bacterial pathogens, there has been an increase in the emergence of, mostly viral, zoonotic diseases from wildlife, sometimes causing fatal outbreaks of epidemic proportions. Concurrently, infectious disease has been identified as an increasing threat to wildlife conservation. A synthesis published in 2000 showed common anthropogenic drivers of disease threats to biodiversity and human health, including encroachment and destruction of wildlife habitat and the human-assisted spread of pathogens. Almost two decades later, the situation has not changed and, despite improved knowledge of the underlying causes, little has been done at the policy level to address these threats. For the sake of public health and wellbeing, human-kind needs to work better to conserve nature and preserve the ecosystem services, including disease regulation, that biodiversity provides while also understanding and mitigating activities which lead to disease emergence. We consider that holistic, One Health approaches to the management and mitigation of the risks of emerging infectious diseases have the greatest chance of success.
This article is part of the themed issue ‘One Health for a changing world: zoonoses, ecosystems and human well-being’.
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Affiliation(s)
- Andrew A. Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
| | - Peter Daszak
- Ecohealth Alliance, 460 West 34th Street, New York, NY 10001, USA
| | - James L. N. Wood
- Department of Veterinary Medicine, Disease Dynamics Unit, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
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Batrachochytrium salamandrivorans is the predominant chytrid fungus in Vietnamese salamanders. Sci Rep 2017; 7:44443. [PMID: 28287614 PMCID: PMC5347381 DOI: 10.1038/srep44443] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
The amphibian chytrid fungi, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), pose a major threat to amphibian biodiversity. Recent evidence suggests Southeast Asia as a potential cradle for both fungi, which likely resulted in widespread host-pathogen co-existence. We sampled 583 salamanders from 8 species across Vietnam in 55 locations for Bsal and Bd, determined scaled mass index as a proxy for fitness and collected environmental data. Bsal was found within 14 of the 55 habitats (2 of which it was detected in 2013), in 5 salamandrid species, with a prevalence of 2.92%. The globalized pandemic lineage of Bd was found within one pond on one species with a prevalence of 0.69%. Combined with a complete lack of correlation between infection and individual body condition and absence of indication of associated disease, this suggests low level pathogen endemism and Bsal and Bd co-existence with Vietnamese salamandrid populations. Bsal was more widespread than Bd, and occurs at temperatures higher than tolerated by the type strain, suggesting a wider thermal niche than currently known. Therefore, this study provides support for the hypothesis that these chytrid fungi may be endemic to Asia and that species within this region may act as a disease reservoir.
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Schmidt BR, Bozzuto C, Lötters S, Steinfartz S. Dynamics of host populations affected by the emerging fungal pathogen Batrachochytrium salamandrivorans. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160801. [PMID: 28405365 PMCID: PMC5383822 DOI: 10.1098/rsos.160801] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/03/2017] [Indexed: 06/07/2023]
Abstract
Emerging infectious diseases cause extirpation of wildlife populations. We use an epidemiological model to explore the effects of a recently emerged disease caused by the salamander-killing chytrid fungus Batrachochytrium salamandrivorans (Bsal) on host populations, and to evaluate which mitigation measures are most likely to succeed. As individuals do not recover from Bsal, we used a model with the states susceptible, latent and infectious, and parametrized the model using data on host and pathogen taken from the literature and expert opinion. The model suggested that disease outbreaks can occur at very low host densities (one female per hectare). This density is far lower than host densities in the wild. Therefore, all naturally occurring populations are at risk. Bsal can lead to the local extirpation of the host population within a few months. Disease outbreaks are likely to fade out quickly. A spatial variant of the model showed that the pathogen could potentially spread rapidly. As disease mitigation during outbreaks is unlikely to be successful, control efforts should focus on preventing disease emergence and transmission between populations. Thus, this emerging wildlife disease is best controlled through prevention rather than subsequent actions.
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Affiliation(s)
- Benedikt R. Schmidt
- Institut für Evolutionsbiologie und Umweltwissenschaften, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
- karch, Passage Maximilien-de-Meuron 6, 2000 Neuchâtel, Switzerland
| | - Claudio Bozzuto
- Wildlife Analysis GmbH, Oetlisbergstrasse 38, 8053 Zürich, Switzerland
| | - Stefan Lötters
- Institut für Biogeographie, Universität Trier, Universitätsring 15, 54296 Trier, Germany
| | - Sebastian Steinfartz
- Department of Evolutionary Biology, Technische Universität Braunschweig, Zoological Institute, Mendelssohnstrasse 4, 38106 Braunschweig, Germany
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Balàž V, Gortázar Schmidt C, Murray K, Carnesecchi E, Garcia A, Gervelmeyer A, Martino L, Munoz Guajardo I, Verdonck F, Zancanaro G, Fabris C. Scientific and technical assistance concerning the survival, establishment and spread of Batrachochytrium salamandrivorans (Bsal) in the EU. EFSA J 2017; 15:e04739. [PMID: 32625419 PMCID: PMC7010177 DOI: 10.2903/j.efsa.2017.4739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A new fungus, Batrachochytrium salamandrivorans (Bsal), was identified in wild populations of salamanders in the Netherlands and Belgium, and in kept salamander populations in Germany and the United Kingdom. EFSA assessed the potential of Bsal to affect the health of wild and kept salamanders in the EU, the effectiveness and feasibility of a movement ban of traded salamanders, the validity, reliability and robustness of available diagnostic methods for Bsal detection, and possible alternative methods and feasible risk mitigation measures to ensure safe international and EU trade of salamanders and their products. Bsal was isolated and characterised in 2013 from a declining fire salamander (Salamandra salamandra) population in the Netherlands. Based on the available evidence, it is likely that Bsal is a sufficient cause for the death of S. salamandra both in the laboratory and in the wild. Despite small sample sizes, the available experimental evidence indicates that Bsal is associated with disease and death in individuals of 12 European and 3 Asian salamander species, and with high mortality rate outbreaks in kept salamanders. Bsal experimental infection was detected in individuals of at least one species pertaining to the families Salamandridae, Plethodontidae, Hynobiidae and Sirenidae. Movement bans constitute key risk mitigation measures to prevent pathogen spread into naïve areas and populations. The effectiveness of a movement ban is mainly dependent on the import volumes, possibility of Bsal to remain viable outside susceptible/tolerant species, and the capacity to limit illegal movements. Duplex real-time PCR can be used to detect Bsal DNA, but has not been fully validated. Quarantining salamanders, enacting legislation that requires testing of animals to demonstrate freedom from Bsal, before movement can take place, restricting salamander movements, tracking all traded species, hygienic procedures/biosecurity measures before and during movements, and increasing public awareness are relevant measures for ensuring safe intra-EU and international trade of salamanders.
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Feldmeier S, Schefczyk L, Wagner N, Heinemann G, Veith M, Lötters S. Exploring the Distribution of the Spreading Lethal Salamander Chytrid Fungus in Its Invasive Range in Europe - A Macroecological Approach. PLoS One 2016; 11:e0165682. [PMID: 27798698 PMCID: PMC5087956 DOI: 10.1371/journal.pone.0165682] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 10/14/2016] [Indexed: 12/11/2022] Open
Abstract
The chytrid fungus Batrachochytrium salamandrivorans (Bsal) is a dangerous pathogen to salamanders and newts. Apparently native to Asia, it has recently been detected in Western Europe where it is expected to spread and to have dramatic effects on naïve hosts. Since 2010, Bsal has led to some catastrophic population declines of urodeles in the Netherlands and Belgium. More recently, it has been discovered in additional, more distant sites including sites in Germany. With the purpose to contribute to a better understanding of Bsal, we modelled its potential distribution in its invasive European range to gain insights about the factors driving this distribution. We computed Bsal Maxent models for two predictor sets, which represent different temporal resolutions, using three different background extents to account for different invasion stage scenarios. Beside 'classical' bioclimate, we employed weather data, which allowed us to emphasize predictors in accordance with the known pathogen's biology. The most important predictors as well as spatial predictions varied between invasion scenarios and predictor sets. The most reasonable model was based on weather data and the scenario of a recent pathogen introduction. It identified temperature predictors, which represent optimal growing conditions and heat limiting conditions, as the most explaining drivers of the current distribution. This model also predicted large areas in the study region as suitable for Bsal. The other models predicted considerably less, but shared some areas which we interpreted as most likely high risk zones. Our results indicate that growth relevant temperatures measured under laboratory conditions might also be relevant on a macroecological scale, if predictors with a high temporal resolution and relevance are used. Additionally, the conditions in our study area support the possibility of a further Bsal spread, especially when considering that our models might tend to underestimate the potential distribution of Bsal.
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Affiliation(s)
| | - Lukas Schefczyk
- Department of Environmental Meteorology, Trier University, Trier, Germany
| | - Norman Wagner
- Department of Biogeography, Trier University, Trier, Germany
| | - Günther Heinemann
- Department of Environmental Meteorology, Trier University, Trier, Germany
| | - Michael Veith
- Department of Biogeography, Trier University, Trier, Germany
| | - Stefan Lötters
- Department of Biogeography, Trier University, Trier, Germany
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Bell BD. A review of potential alpine newt (Ichthyosaura alpestris) impacts on native frogs in New Zealand. J R Soc N Z 2016. [DOI: 10.1080/03036758.2016.1216455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Spitzen-van der Sluijs A, Martel A, Asselberghs J, Bales EK, Beukema W, Bletz MC, Dalbeck L, Goverse E, Kerres A, Kinet T, Kirst K, Laudelout A, Marin da Fonte LF, Nöllert A, Ohlhoff D, Sabino-Pinto J, Schmidt BR, Speybroeck J, Spikmans F, Steinfartz S, Veith M, Vences M, Wagner N, Pasmans F, Lötters S. Expanding Distribution of Lethal Amphibian Fungus Batrachochytrium salamandrivorans in Europe. Emerg Infect Dis 2016; 22:1286-8. [PMID: 27070102 PMCID: PMC4918153 DOI: 10.3201/eid2207.160109] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Emerging fungal diseases can drive amphibian species to local extinction. During 2010–2016, we examined 1,921 urodeles in 3 European countries. Presence of the chytrid fungus Batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity.
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Richgels KLD, Russell RE, Adams MJ, White CL, Grant EHC. Spatial variation in risk and consequence of Batrachochytrium salamandrivorans introduction in the USA. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150616. [PMID: 26998331 PMCID: PMC4785982 DOI: 10.1098/rsos.150616] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/22/2016] [Indexed: 05/07/2023]
Abstract
A newly identified fungal pathogen, Batrachochytrium salamandrivorans(Bsal), is responsible for mass mortality events and severe population declines in European salamanders. The eastern USA has the highest diversity of salamanders in the world and the introduction of this pathogen is likely to be devastating. Although data are inevitably limited for new pathogens, disease-risk assessments use best available data to inform management decisions. Using characteristics of Bsalecology, spatial data on imports and pet trade establishments, and salamander species diversity, we identify high-risk areas with both a high likelihood of introduction and severe consequences for local salamanders. We predict that the Pacific coast, southern Appalachian Mountains and mid-Atlantic regions will have the highest relative risk from Bsal. Management of invasive pathogens becomes difficult once they are established in wildlife populations; therefore, import restrictions to limit pathogen introduction and early detection through surveillance of high-risk areas are priorities for preventing the next crisis for North American salamanders.
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Affiliation(s)
- Katherine L. D. Richgels
- US Geological Survey National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711, USA
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin—Madison, 2015 Linden Drive, Madison, WI 53706, USA
- Author for correspondence: Katherine L. D. Richgels e-mail:
| | - Robin E. Russell
- US Geological Survey National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711, USA
| | - Michael J. Adams
- US Geological Survey Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA
| | - C. LeAnn White
- US Geological Survey National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711, USA
| | - Evan H. Campbell Grant
- US Geological Survey Patuxent Wildlife Research Center, SO Conte Anadromous Fish Research Laboratory, 1 Migratory Way, Turner Falls, MA 01376, USA
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Van Rooij P, Martel A, Haesebrouck F, Pasmans F. Amphibian chytridiomycosis: a review with focus on fungus-host interactions. Vet Res 2015; 46:137. [PMID: 26607488 PMCID: PMC4660679 DOI: 10.1186/s13567-015-0266-0] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/05/2015] [Indexed: 01/30/2023] Open
Abstract
Amphibian declines and extinctions are emblematic for the current sixth mass extinction event. Infectious drivers of these declines include the recently emerged fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans (Chytridiomycota). The skin disease caused by these fungi is named chytridiomycosis and affects the vital function of amphibian skin. Not all amphibians respond equally to infection and host responses might range from resistant, over tolerant to susceptible. The clinical outcome of infection is highly dependent on the amphibian host, the fungal virulence and environmental determinants. B. dendrobatidis infects the skin of a large range of anurans, urodeles and caecilians, whereas to date the host range of B. salamandrivorans seems limited to urodeles. So far, the epidemic of B. dendrobatidis is mainly limited to Australian, neotropical, South European and West American amphibians, while for B. salamandrivorans it is limited to European salamanders. Other striking differences between both fungi include gross pathology and thermal preferences. With this review we aim to provide the reader with a state-of-the art of host-pathogen interactions for both fungi, in which new data pertaining to the interaction of B. dendrobatidis and B. salamandrivorans with the host’s skin are integrated. Furthermore, we pinpoint areas in which more detailed studies are necessary or which have not received the attention they merit.
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Affiliation(s)
- Pascale Van Rooij
- Laboratory of Veterinary Bacteriology and Mycology, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - An Martel
- Laboratory of Veterinary Bacteriology and Mycology, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Freddy Haesebrouck
- Laboratory of Veterinary Bacteriology and Mycology, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Frank Pasmans
- Laboratory of Veterinary Bacteriology and Mycology, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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Yap TA, Koo MS, Ambrose RF, Wake DB, Vredenburg VT. BIODIVERSITY. Averting a North American biodiversity crisis. Science 2015; 349:481-2. [PMID: 26228132 DOI: 10.1126/science.aab1052] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Tiffany A Yap
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA, USA. Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA. Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - Michelle S Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
| | - Richard F Ambrose
- Institute of the Environment and Sustainability, University of California, Los Angeles, CA, USA. Department of Environmental Health Sciences, University of California, Los Angeles, CA, USA
| | - David B Wake
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA. Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Vance T Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA. Department of Biology, San Francisco State University, San Francisco, CA, USA.
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Sabino-Pinto J, Bletz M, Hendrix R, Perl RB, Martel A, Pasmans F, Lötters S, Mutschmann F, Schmeller DS, Schmidt BR, Veith M, Wagner N, Vences M, Steinfartz S. First detection of the emerging fungal pathogen Batrachochytrium salamandrivorans in Germany. AMPHIBIA-REPTILIA 2015. [DOI: 10.1163/15685381-00003008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The emerging infectious disease chytridiomycosis is one of the major factors triggering global amphibian declines. A recently discovered species of chytrid fungus,Batrachochytrium salamandrivorans(Bsal), likely originated in East Asia, has led to massive declines in populations of fire salamanders (Salamandra salamandra) after its apparent introduction to the Netherlands and Belgium. Here, we report the first detection of this pathogen in Germany where it caused mass mortality of fire salamanders in a captive collection. Salamanders from this collection showed an almost 100% prevalence of infection withBsal. SupposedBsal-induced mortality occurred in multipleSalamandraspecies (S. salamandra,S. algira,S. corsica, andS. infraimmaculata), whileBsalinfection was confirmed in nine subspecies ofS. salamandraand inS. algira. Our study indicates that this pathogen can potentially infect all fire salamander species and subspecies. IfBsalspreads from captive collections to wild populations, then a similar devastating effect associated with high mortality should be expected.
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Affiliation(s)
- Joana Sabino-Pinto
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Molly Bletz
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Ralf Hendrix
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - R.G. Bina Perl
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Stefan Lötters
- Department of Biogeography, Trier University, Trier, Germany
| | - Frank Mutschmann
- Exomed – Institut für veterinärmedizinische Betreuung niederer Wirbeltiere und Exoten, Berlin, Germany
| | - Dirk S. Schmeller
- UFZ – Helmholtz Centre for Environmental Research, Department of Conservation Biology, Leipzig, Germany
| | - Benedikt R. Schmidt
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- KARCH, Neuchâtel, Switzerland
| | - Michael Veith
- Department of Biogeography, Trier University, Trier, Germany
| | - Norman Wagner
- Department of Biogeography, Trier University, Trier, Germany
| | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Sebastian Steinfartz
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
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