1
|
Forrest MJ, Halstead BJ, Grear DA, Kleeman PM, Todd BD, Miano OJ, Urquhart KD. KEEPING THE HEAT ON: WEIGHTED SURVEILLANCE FOR CHYTRID FUNGUS (BATRACHOCHYTRIUM DENDROBATIDIS) IN DIXIE VALLEY TOADS (ANAXYRUS [= BUFO] WILLIAMSI). J Wildl Dis 2023; 59:557-568. [PMID: 37486870 DOI: 10.7589/jwd-d-22-00049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 03/09/2023] [Indexed: 07/26/2023]
Abstract
Introduced fungal pathogens have caused declines and extinctions of naïve wildlife populations across vertebrate classes. Consequences of introduced pathogens to hosts with small ranges might be especially severe because of limited redundancy to rescue populations and lower abundance that may limit the resilience of populations to perturbations like disease introduction. As a complement to biosecurity measures to prevent the spread of pathogens, surveillance programs may enable early detection of pathogens, when management actions to limit the effects of pathogens on naïve hosts might be most beneficial. We analyzed surveillance data for the endangered and narrowly endemic Dixie Valley toad (Anaxyrus [= Bufo] williamsi) from two time periods (2011-2014 and 2019-2021) to estimate the minimum detectable prevalence of the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd). We assessed if detection efficiency could be improved by using samples from both Dixie Valley toads and co-occurring introduced American bullfrogs (Lithobates catesbeianus) and literature-derived surveillance weights. We further evaluated a weighted surveillance design to increase the efficiency of surveillance efforts for Bd within the toad's small (<6 km2) range. We found that monitoring adult and larval American bullfrogs would probably detect Bd more efficiently than monitoring Dixie Valley toads alone. Given that no Bd was detected, minimum detectable prevalence of Bd was <3% in 2011-2014, and <5% (Dixie Valley toads only) and <10% (American bullfrogs only) in 2019-2021. Optimal management for Bd depends on the mechanisms underlying its apparent absence from the range of Dixie Valley toads, but a balanced surveillance scheme that includes sampling American bullfrogs to increase the likelihood of detecting Bd, and adult Dixie Valley toads to ensure broad spatial coverage where American bullfrogs do not occur, would probably result in efficient surveillance, which might permit timely management of Bd if it is detected.
Collapse
Affiliation(s)
- Matthew J Forrest
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
- Co-primary authors
| | - Brian J Halstead
- US Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, California 95620, USA
- Co-primary authors
| | - Daniel A Grear
- US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, Wisconsin 53711, USA
| | - Patrick M Kleeman
- US Geological Survey, Western Ecological Research Center, Point Reyes Field Station, 1 Bear Valley Road, Point Reyes Station, California 94956, USA
| | - Brian D Todd
- Department of Wildlife, Fish, and Conservation Biology, University of California-Davis, One Shields Avenue, Davis, California 95616, USA
| | - Oliver J Miano
- Department of Wildlife, Fish, and Conservation Biology, University of California-Davis, One Shields Avenue, Davis, California 95616, USA
| | - Kris D Urquhart
- Nevada Department of Wildlife, 380 West B Street, Fallon, Nevada 89406, USA
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Dampened virulence and limited proliferation of Batrachochytrium salamandrivorans during subclinical infection of the troglobiont olm (Proteus anguinus). Sci Rep 2020; 10:16480. [PMID: 33020584 PMCID: PMC7536193 DOI: 10.1038/s41598-020-73800-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/15/2020] [Indexed: 11/25/2022] Open
Abstract
Emerging infections add to existing threats to the survival of amphibians worldwide. The olm (Proteus anguinus) is a vulnerable, troglobiont urodele species with a small European range and restricted to underground karstic systems. Population declines to emerging threats like the chytrid fungus Batrachochytrium salamandrivorans, are likely to go unnoticed due to inaccessibility of the species’ habitat. We here studied the interaction between olms and B. salamandrivorans. Experimental inoculation of olms resulted in low-level, asymptomatic but persistent infections, with limbs as predilection sites. The lack of exponential fungal growth in the olms’ epidermis correlated with limited fungal proliferation and dampened virulence gene expression after exposure to olm skin compounds. The olm is one of few western Palearctic urodeles that is tolerant to B. salamandrivorans infection and may act as a subterranean disease reservoir, yet costs of subclinical infection may compromise olm fitness on the long term.
Collapse
|
4
|
Sette CM, Vredenburg VT, Zink AG. Differences in Fungal Disease Dynamics in Co-occurring Terrestrial and Aquatic Amphibians. ECOHEALTH 2020; 17:302-314. [PMID: 33237500 DOI: 10.1007/s10393-020-01501-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 09/14/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
The fungal pathogen, Batrachochytrium dendrobatidis (Bd), has devastated biodiversity and ecosystem health and is implicated as a driver of mass amphibian extinctions. This 100-year study investigates which environmental factors contribute to Bd prevalence in a fully terrestrial species, and determines whether infection patterns differ between a fully terrestrial amphibian and more aquatic host species. We performed a historical survey to quantify Bd prevalence in 1127 Batrachoseps gregarius museum specimens collected from 1920 to 2000, and recent data from 16 contemporary (live-caught) B. gregarius populations from the southwestern slopes of the Sierra Nevada mountains in California, USA. We compared these results to Bd detection rates in 1395 historical and 1033 contemporary specimens from 10 species of anurans and 427 historical Taricha salamander specimens collected throughout the Sierra Nevada mountains. Our results indicate that Bd dynamics in the entirely terrestrial species, B. gregarius, differ from aquatic species in the same region in terms of both seasonal patterns of Bd abundance and in the possible timing of Bd epizootics.
Collapse
Affiliation(s)
- Carla M Sette
- University of California, Santa Cruz, EEB/CBB mailstop, UCSC/Coastal Biology Building, 130 McAllister Way, Santa Cruz, CA, 95060, USA.
| | | | | |
Collapse
|
5
|
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.
Collapse
|
6
|
Jacinto-Maldonado M, García-Peña G, Paredes-León R, Saucedo B, Sarmiento-Silva R, García A, Martínez-Gómez D, Ojeda M, Del Callejo E, Suzán G. Chiggers (Acariformes: Trombiculoidea) do not increase rates of infection by Batrachochytrium dendrobatidis fungus in the endemic Dwarf Mexican Treefrog Tlalocohyla smithii (Anura: Hylidae). Int J Parasitol Parasites Wildl 2020; 11:163-173. [PMID: 32099787 PMCID: PMC7031141 DOI: 10.1016/j.ijppaw.2019.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/16/2019] [Accepted: 12/16/2019] [Indexed: 12/29/2022]
Abstract
Amphibian populations are globally declining at an alarming rate, and infectious diseases are among the main causes of their decline. Two micro-parasites, the fungus Batrachochytrium dendrobatidis (Bd) and the virus Ranavirus (RV) have caused mass mortality of amphibians and population declines. Other, less understood epizootics are caused by macro-parasites, such as Trombiculoidea chiggers. Infection with chiggers can affect frog behavior and survival. Furthermore, synergistic effects of co-infection with both macro and micro-parasites may lead to higher morbidity. To better understand these potential synergies, we investigated the presence and co-infection by chiggers, Bd and RV in the endemic frog Tlalocohyla smithii (T. smithii). Co-infection of Bd, RV, and/or chiggers is expected in habitats that are suitable for their co-occurrence; and if infection with one parasite facilitates infection with the others. On the other hand, co-infection could decrease if these parasites were to differ in their micro-environmental requirements (i.e. niche apportionment). A total of 116 frogs of T. smithii were studied during 2014 and 2016 in three streams within the Chamela-Cuixmala Biosphere Reserve in Jalisco, Mexico. Our results show that 31% of the frogs were infected with Trombiculoidea chiggers (Hannemania sp. and Eutrombicula alfreddugesi); Hannemania prevalence increased with air temperature and decreased in sites with high canopies and with water pH values above 8.5 and below 6.7. Bd prevalence was 2.6%, RV prevalence was 0%, and none of the frogs infected with chiggers were co-infected with Bd. Together, this study suggests that chiggers do not facilitate infection with Bd, as these are apportioned in different micro-habitats. Nevertheless, the statistical power to assure this is low. We recommend further epidemiological monitoring of multiple parasites in different geographical locations in order to provide insight on the true hazards, risks and conservation options for amphibian populations.
Collapse
Affiliation(s)
- M. Jacinto-Maldonado
- The Complexity Sciences Center C3 Universidad Nacional Autónoma de México, Av. Universidad, 3000, Mexico City, Mexico
- Faculty of Veterinary Medicine, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 3000, Mexico City, Mexico
| | - G.E. García-Peña
- The Complexity Sciences Center C3 Universidad Nacional Autónoma de México, Av. Universidad, 3000, Mexico City, Mexico
- Faculty of Veterinary Medicine, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 3000, Mexico City, Mexico
| | - R. Paredes-León
- National Mite Collection, Biology Institute, Universidad Nacional Autónoma de México, Mexico
| | - B. Saucedo
- Animal Health Trust, Lanwades Park, CB87UU, Newmarket, United Kingdom
| | - R.E. Sarmiento-Silva
- Faculty of Veterinary Medicine, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 3000, Mexico City, Mexico
| | - A. García
- Chamela Biological Station, Biology Institute, San Patricio Melaque, 48980, La Huerta, Jalisco, Mexico
| | - D. Martínez-Gómez
- Department of Agriculture and Animal Production, Universidad Autónoma Metropolitana. Unit of Xochimilco. Prol, Canal de Miramontes, 3855, Mexico City, Mexico
| | - M. Ojeda
- National Mite Collection, Biology Institute, Universidad Nacional Autónoma de México, Mexico
| | - E. Del Callejo
- The Complexity Sciences Center C3 Universidad Nacional Autónoma de México, Av. Universidad, 3000, Mexico City, Mexico
| | - G. Suzán
- Faculty of Veterinary Medicine, Universidad Nacional Autónoma de México (UNAM), Av. Universidad, 3000, Mexico City, Mexico
| |
Collapse
|
7
|
Bolom‐Huet R, Pineda E, Díaz‐Fleischer F, Muñoz‐Alonso AL, Galindo‐González J. Known and estimated distribution in Mexico of
Batrachochytrium dendrobatidis,
a pathogenic fungus of amphibians. Biotropica 2019. [DOI: 10.1111/btp.12697] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | - Eduardo Pineda
- Red de Biología y Conservación de Vertebrados Instituto de Ecología A. C. Xalapa Veracruz México
| | | | | | | |
Collapse
|
8
|
Sunny A, Duarte-deJesus L, Aguilera-Hernández A, Ramírez-Corona F, Suárez-Atilano M, Percino-Daniel R, Manjarrez J, Monroy-Vilchis O, González-Fernández A. Genetic diversity and demography of the critically endangered Roberts' false brook salamander (Pseudoeurycea robertsi) in Central Mexico. Genetica 2019; 147:149-164. [PMID: 30879155 DOI: 10.1007/s10709-019-00058-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 03/11/2019] [Indexed: 11/28/2022]
Abstract
Land use changes are threatening the maintenance of biodiversity. Genetic diversity is one of the main indicators of biological diversity and is highly important as it shapes the capability of populations to respond to environmental changes. We studied eleven populations of Pseudoeurycea robertsi, a micro-endemic and critically endangered species from the Nevado de Toluca Volcano, a mountain that is part of the Trans-Mexican Volcanic Belt, Mexico. We sequenced the mitochondrial cytochrome b gene from 71 individuals and genotyped 9 microsatellites from 150 individuals. Our results based on the cytochrome b showed two divergent lineages, with moderate levels of genetic diversity and a recently historical demographic expansion. Microsatellite-based results indicated low levels of heterozygosity for all populations and few alleles per locus, as compared with other mole salamander species. We identified two genetically differentiated subpopulations with a significant level of genetic structure. These results provide fundamental data for the development of management plans and conservation efforts for this critically endangered species.
Collapse
Affiliation(s)
- Armando Sunny
- Centro de Investigación en Ciencias Biológicas Aplicadas, Universidad Autónoma del Estado de México, Instituto Literario #100, Colonia Centro, 50000, Toluca, Mexico State, Mexico.
| | - Luis Duarte-deJesus
- Centro de Investigación en Ciencias Biológicas Aplicadas, Universidad Autónoma del Estado de México, Instituto Literario #100, Colonia Centro, 50000, Toluca, Mexico State, Mexico
| | - Arlene Aguilera-Hernández
- Centro de Investigación en Ciencias Biológicas Aplicadas, Universidad Autónoma del Estado de México, Instituto Literario #100, Colonia Centro, 50000, Toluca, Mexico State, Mexico
| | - Fabiola Ramírez-Corona
- Taller de Sistemática y Biogeografía, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Mexico City, Mexico
| | - Marco Suárez-Atilano
- Departamento de Ecología de la Biodiversidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Mexico City, Mexico
| | - Ruth Percino-Daniel
- Departamento de Ecología de la Biodiversidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Mexico City, Mexico
| | - Javier Manjarrez
- Laboratorio de Biología Evolutiva, Facultad de Ciencias, Universidad Autónoma del Estado de México, Instituto Literario #100, Colonia Centro, 50000, Toluca, Mexico State, Mexico
| | - Octavio Monroy-Vilchis
- Centro de Investigación en Ciencias Biológicas Aplicadas, Universidad Autónoma del Estado de México, Instituto Literario #100, Colonia Centro, 50000, Toluca, Mexico State, Mexico
| | - Andrea González-Fernández
- Laboratorio de Biología Evolutiva, Facultad de Ciencias, Universidad Autónoma del Estado de México, Instituto Literario #100, Colonia Centro, 50000, Toluca, Mexico State, Mexico
| |
Collapse
|
9
|
Post-epizootic salamander persistence in a disease-free refugium suggests poor dispersal ability of Batrachochytrium salamandrivorans. Sci Rep 2018; 8:3800. [PMID: 29491409 PMCID: PMC5830533 DOI: 10.1038/s41598-018-22225-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 02/19/2018] [Indexed: 12/11/2022] Open
Abstract
Lack of disease spill-over between adjacent populations has been associated with habitat fragmentation and the absence of population connectivity. We here present a case which describes the absence of the spill-over of the chytrid fungus Batrachochytrium salamandrivorans (Bsal) between two connected subpopulations of fire salamanders (Salamandra salamandra). Based on neutrally evolving microsatellite loci, both subpopulations were shown to form a single genetic cluster, suggesting a shared origin and/or recent gene flow. Alpine newts (Ichthyosaura alpestris) and fire salamanders were found in the landscape matrix between the two sites, which are also connected by a stream and separated by no obvious physical barriers. Performing a laboratory trial using alpine newts, we confirmed that Bsal is unable to disperse autonomously. Vector-mediated dispersal may have been impeded by a combination of sub-optimal connectivity, limited dispersal ability of infected hosts and a lack of suitable dispersers following the rapid, Bsal-driven collapse of susceptible hosts at the source site. Although the exact cause remains unclear, the aggregate evidence suggests that Bsal may be a poorer disperser than previously hypothesized. The lack of Bsal dispersal between neighbouring salamander populations opens perspectives for disease management and stresses the necessity of implementing biosecurity measures preventing human-mediated spread.
Collapse
|
10
|
Blooi M, Laking AE, Martel A, Haesebrouck F, Jocque M, Brown T, Green S, Vences M, Bletz MC, Pasmans F. Host niche may determine disease-driven extinction risk. PLoS One 2017; 12:e0181051. [PMID: 28704480 PMCID: PMC5509289 DOI: 10.1371/journal.pone.0181051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 06/26/2017] [Indexed: 12/31/2022] Open
Abstract
The fungal pathogen Batrachochytrium dendrobatidis (Bd) drives declines and extinctions in amphibian communities. However, not all regions and species are equally affected. Here, we show that association with amphibian aquatic habitat types (bromeliad phytotelmata versus stream) across Central America results in the odds of being threatened by Bd being five times higher in stream microhabitats. This differential threat of Bd was supported in our study by a significantly lower prevalence of Bd in bromeliad-associated amphibian species compared to riparian species in Honduran cloud forests. Evidence that the bromeliad environment is less favorable for Bd transmission is exemplified by significantly less suitable physicochemical conditions and higher abundance of Bd-ingesting micro-eukaryotes present in bromeliad water. These factors may inhibit aquatic Bd zoospore survival and the development of an environmental reservoir of the pathogen. Bromeliad phytotelmata thus may act as environmental refuges from Bd, which contribute to protecting associated amphibian communities against chytridiomycosis-driven amphibian declines that threaten the nearby riparian communities.
Collapse
Affiliation(s)
- Mark Blooi
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Alexandra E. Laking
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- Operation Wallacea, Hope House, Old Bolingbroke, Lincolnshire, United Kingdom
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Merlijn Jocque
- Operation Wallacea, Hope House, Old Bolingbroke, Lincolnshire, United Kingdom
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Tom Brown
- Operation Wallacea, Hope House, Old Bolingbroke, Lincolnshire, United Kingdom
| | - Stephen Green
- Operation Wallacea, Hope House, Old Bolingbroke, Lincolnshire, United Kingdom
- Centre for Applied Zoology, Cornwall College Newquay, Cornwall, United Kingdom
| | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Molly C. Bletz
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| |
Collapse
|
11
|
Stark T, Laurijssens C, Weterings M, Martel A, Köhler G, Pasmans F. Prevalence of Batrachochytrium dendrobatidis in a Nicaraguan, micro-endemic Neotropical salamander, Bolitoglossa mombachoensis. AMPHIBIA-REPTILIA 2017. [DOI: 10.1163/15685381-00003077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Amphibians are the most threatened terrestrial vertebrates on the planet and are iconic in the global biodiversity crisis. Their global decline caused by the fungal agentBatrachochytrium dendrobatidis(Bd) is well known. Declines of Mesoamerican salamanders of the family Plethodontidae, mainly affecting high elevation species, have equally been attributed toBd. Here we report the prevalence ofBdin a population of a high elevationBolitoglossaspecies in Nicaragua, since its description in 1999 until 2011 in the absence of any obvious population declines. Our findings show a low prevalence in an environmental context where pathogen driven declines would be expected to occur.
Collapse
Affiliation(s)
- Tariq Stark
- Van Hall Larenstein University of Applied Sciences, Agora 1, 8934 CJ Leeuwarden, The Netherlands
| | - Carlijn Laurijssens
- Van Hall Larenstein University of Applied Sciences, Agora 1, 8934 CJ Leeuwarden, The Netherlands
| | - Martijn Weterings
- Van Hall Larenstein University of Applied Sciences, Agora 1, 8934 CJ Leeuwarden, The Netherlands
- Wageningen University and Research Center, Resource Ecology Group, Droevendaalsesteeg 3a, 6708 PB Wageningen, The Netherlands
| | - An Martel
- Ghent University, Department of Pathology, Bacteriology and Avian Diseases, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Gunther Köhler
- Senckenberg, Forschungsinstitute und Naturmuseen, Senckenberganlag 25, Frankfurt a.M., Germany
| | - Frank Pasmans
- Ghent University, Department of Pathology, Bacteriology and Avian Diseases, Salisburylaan 133, 9820 Merelbeke, Belgium
| |
Collapse
|
12
|
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.
Collapse
|
13
|
Temperature treatments boost subclinical infections of Batrachochytrium dendrobatidis in a Mexican salamander (Pseudoeurycea leprosa). REV MEX BIODIVERS 2016. [DOI: 10.1016/j.rmb.2016.01.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
14
|
Yap TA, Gillespie L, Ellison S, Flechas SV, Koo MS, Martinez AE, Vredenburg VT. Invasion of the Fungal Pathogen Batrachochytrium dendrobatidis on California Islands. ECOHEALTH 2016; 13:145-150. [PMID: 26493624 DOI: 10.1007/s10393-015-1071-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Abstract
Batrachochytrium dendrobatidis (Bd), an amphibian fungal pathogen, has infected >500 species and caused extinctions or declines in >200 species worldwide. Despite over a decade of research, little is known about its invasion biology. To better understand this, we conducted a museum specimen survey (1910-1997) of Bd in amphibians on 11 California islands and found a pattern consistent with the emergence of Bd epizootics on the mainland, suggesting that geographic isolation did not prevent Bd invasion. We propose that suitable habitat, host diversity, and human visitation overcome isolation from the mainland and play a role in Bd invasion.
Collapse
Affiliation(s)
- Tiffany A Yap
- Institute of the Environment and Sustainability, University of California, La Kretz Hall, Suite 300, 619 Charles E Young Drive, Los Angeles, CA, 90095, USA
- Museum of Vertebrate Zoology, University of California, 3101 Valley Life Sciences Building #3160, Berkeley, CA, 94720, USA
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Lauren Gillespie
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Silas Ellison
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, Bogotá, AA 4976, Colombia
| | - Michelle S Koo
- Museum of Vertebrate Zoology, University of California, 3101 Valley Life Sciences Building #3160, Berkeley, CA, 94720, USA
| | - Ari E Martinez
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA
| | - Vance T Vredenburg
- Museum of Vertebrate Zoology, University of California, 3101 Valley Life Sciences Building #3160, Berkeley, CA, 94720, USA.
- Department of Biology, San Francisco State University, Hensill Hall, 1600 Holloway Ave., San Francisco, CA, 94132, USA.
| |
Collapse
|
15
|
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: 114] [Impact Index Per Article: 12.7] [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.
Collapse
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.
| |
Collapse
|
16
|
Presence and prevalence of Batrachochytrium dendrobatidis in commercial amphibians in Mexico City. J Zoo Wildl Med 2015; 45:830-5. [PMID: 25632670 DOI: 10.1638/2014-0023.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In Mexico City, native and exotic amphibians are commonly sold through the pet trade. This study investigates the presence of Batrachochytrium dendrobatidis (Bd) in native amphibians being sold at two commercial markets and at a herpetarium in Mexico City. A total of 238 individuals (6 genera and 12 species) were tested for Bd using real-time polymerase chain reaction (PCR) analysis. There were 197 Bd-positive individuals (prevalence 82%) from five species of amphibians. Hyla eximia from the markets had very high Bd prevalence (100%; 76/76 and 99%; 88/89) but those from the herpetarium were Bd negative (0/12). Ambystoma mexicanum from the herpetarium also had a high Bd-positive prevalence (80%; 28/35). Though A. mexicanum is nearly extinct in the wild, a commercial market continues to flourish through the pet trade. Now that captive colonies of A. mexicanum are currently used for reintroduction programs, the authors recommend quarantine to reduce spread of Bd via movement of infected animals in the trade and between colonies and via disposal of wastewater from captive collections.
Collapse
|
17
|
Mendoza-Almeralla C, Burrowes P, Parra-Olea G. La quitridiomicosis en los anfibios de México: una revisión. REV MEX BIODIVERS 2015. [DOI: 10.7550/rmb.42588] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
18
|
BATRACHOCHYTRIUM DENDROBATIDISIN AQUATIC CAECILIANS (TYPHLONECTES NATANS): A SERIES OF CASES FROM TWO INSTITUTIONS. J Zoo Wildl Med 2013; 44:1002-9. [DOI: 10.1638/2012-0288r1.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
19
|
Duplex real-time PCR for rapid simultaneous detection of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans in Amphibian samples. J Clin Microbiol 2013; 51:4173-7. [PMID: 24108616 DOI: 10.1128/jcm.02313-13] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chytridiomycosis is a lethal fungal disease contributing to declines and extinctions of amphibian species worldwide. The currently used molecular screening tests for chytridiomycosis fail to detect the recently described species Batrachochytrium salamandrivorans. In this study, we present a duplex real-time PCR that allows the simultaneous detection of B. salamandrivorans and Batrachochytrium dendrobatidis. With B. dendrobatidis- and B. salamandrivorans-specific primers and probes, detection of the two pathogens in amphibian samples is possible, with a detection limit of 0.1 genomic equivalent of zoospores of both pathogens per PCR. The developed real-time PCR shows high degrees of specificity and sensitivity, high linear correlations (r(2) > 0.995), and high amplification efficiencies (>94%) for B. dendrobatidis and B. salamandrivorans. In conclusion, the described duplex real-time PCR can be used to detect DNA of B. dendrobatidis and B. salamandrivorans with highly reproducible and reliable results.
Collapse
|
20
|
Pasmans F, Van Rooij P, Blooi M, Tessa G, Bogaerts S, Sotgiu G, Garner TWJ, Fisher MC, Schmidt BR, Woeltjes T, Beukema W, Bovero S, Adriaensen C, Oneto F, Ottonello D, Martel A, Salvidio S. Resistance to chytridiomycosis in European plethodontid salamanders of the genus Speleomantes. PLoS One 2013; 8:e63639. [PMID: 23703511 PMCID: PMC3659026 DOI: 10.1371/journal.pone.0063639] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 04/04/2013] [Indexed: 11/18/2022] Open
Abstract
North America and the neotropics harbor nearly all species of plethodontid salamanders. In contrast, this family of caudate amphibians is represented in Europe and Asia by two genera, Speleomantes and Karsenia, which are confined to small geographic ranges. Compared to neotropical and North American plethodontids, mortality attributed to chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) has not been reported for European plethodontids, despite the established presence of Bd in their geographic distribution. We determined the extent to which Bd is present in populations of all eight species of European Speleomantes and show that Bd was undetectable in 921 skin swabs. We then compared the susceptibility of one of these species, Speleomantes strinatii, to experimental infection with a highly virulent isolate of Bd (BdGPL), and compared this to the susceptible species Alytes muletensis. Whereas the inoculated A. muletensis developed increasing Bd-loads over a 4-week period, none of five exposed S. strinatii were colonized by Bd beyond 2 weeks post inoculation. Finally, we determined the extent to which skin secretions of Speleomantes species are capable of killing Bd. Skin secretions of seven Speleomantes species showed pronounced killing activity against Bd over 24 hours. In conclusion, the absence of Bd in Speleomantes combined with resistance to experimental chytridiomycosis and highly efficient skin defenses indicate that the genus Speleomantes is a taxon unlikely to decline due to Bd.
Collapse
Affiliation(s)
- Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|