1
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McEachran MC, Harvey JA, Mummah RO, Bletz MC, Teitelbaum CS, Rosenblatt E, Rudolph FJ, Arce F, Yin S, Prosser DJ, Mosher BA, Mullinax JM, DiRenzo GV, Couret J, Runge MC, Grant EHC, Cook JD. Reframing wildlife disease management problems with decision analysis. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2024; 38:e14284. [PMID: 38785034 DOI: 10.1111/cobi.14284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 01/30/2024] [Accepted: 02/09/2024] [Indexed: 05/25/2024]
Abstract
Contemporary wildlife disease management is complex because managers need to respond to a wide range of stakeholders, multiple uncertainties, and difficult trade-offs that characterize the interconnected challenges of today. Despite general acknowledgment of these complexities, managing wildlife disease tends to be framed as a scientific problem, in which the major challenge is lack of knowledge. The complex and multifactorial process of decision-making is collapsed into a scientific endeavor to reduce uncertainty. As a result, contemporary decision-making may be oversimplified, rely on simple heuristics, and fail to account for the broader legal, social, and economic context in which the decisions are made. Concurrently, scientific research on wildlife disease may be distant from this decision context, resulting in information that may not be directly relevant to the pertinent management questions. We propose reframing wildlife disease management challenges as decision problems and addressing them with decision analytical tools to divide the complex problems into more cognitively manageable elements. In particular, structured decision-making has the potential to improve the quality, rigor, and transparency of decisions about wildlife disease in a variety of systems. Examples of management of severe acute respiratory syndrome coronavirus 2, white-nose syndrome, avian influenza, and chytridiomycosis illustrate the most common impediments to decision-making, including competing objectives, risks, prediction uncertainty, and limited resources.
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Affiliation(s)
- Margaret C McEachran
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
| | - Johanna A Harvey
- Department of Environmental Science and Technology, University of Maryland, College Park, Maryland, USA
| | - Riley O Mummah
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
| | - Molly C Bletz
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
| | - Claire S Teitelbaum
- Akima Systems Engineering, Herndon, Virginia, USA
- Contractor to Eastern Ecological Science Center at Patuxent Research Refuge, U.S. Geological Survey, Laurel, Maryland, USA
| | - Elias Rosenblatt
- Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, USA
| | - F Javiera Rudolph
- Department of Ecosystem Sciences and Management, Pennsylvania State University, Center Valley, Pennsylvania, USA
| | - Fernando Arce
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Starkville, Mississippi, USA
| | - Shenglai Yin
- School of Biological Sciences, Center for Earth Observation and Modeling, University of Oklahoma, Norman, Oklahoma, USA
| | - Diann J Prosser
- Eastern Ecological Science Center at Patuxent Research Refuge, U.S. Geological Survey, Laurel, Maryland, USA
| | - Brittany A Mosher
- Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, USA
| | - Jennifer M Mullinax
- Department of Environmental Science and Technology, University of Maryland, College Park, Maryland, USA
| | - Graziella V DiRenzo
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
- Massachusetts Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jannelle Couret
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Michael C Runge
- Eastern Ecological Science Center at Patuxent Research Refuge, U.S. Geological Survey, Laurel, Maryland, USA
| | - Evan H Campbell Grant
- Eastern Ecological Science Center at the S.O. Conte Research Laboratory, U.S. Geological Survey, Turners Falls, Massachusetts, USA
| | - Jonathan D Cook
- Eastern Ecological Science Center at Patuxent Research Refuge, U.S. Geological Survey, Laurel, Maryland, USA
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2
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Marini D, Szczygieł P, Kurek K, Di Nicola MR, Dorne JLCM, Marenzoni ML, Rüegg J, Bury S, Kiraga Ł. Retrospective Detection of Ophidiomyces ophidiicola from Snake Moults Collected in Bieszczady Mountains, Poland. Microorganisms 2024; 12:1467. [PMID: 39065236 PMCID: PMC11279008 DOI: 10.3390/microorganisms12071467] [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: 06/30/2024] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
Ophidiomyces ophidiicola, the causative agent of ophidiomycosis, poses a potential threat to wild snakes worldwide. This study aimed to retrospectively investigate the prevalence of O. ophidiicola in archived snake moults collected from the San River Valley in the Bieszczady Mountains, Poland, from 2010 to 2012. Using qPCR for O. ophidiicola detection and conventional PCR for clade characterisation, we analysed 58 moults and one road-killed specimen of Zamenis longissimus and Natrix natrix. A novel combination of primers (ITS2L) was used to simultaneously confirm SYBR Green-based qPCR results and perform genotyping. O. ophidiicola has been detected from two Z. longissimus and one N. natrix specimens. The identified clade (I-B) is consistent with those found in wild snakes of eastern Europe and San River Valley, indicating that O. ophidiicola has been present in this region for at least a decade. This study underscores the value of historical samples in understanding the long-term presence of pathogens and highlights the potential role of environmental reservoirs in the persistence of O. ophidiicola. Our findings are crucial for informing conservation strategies for the endangered Aesculapian snake populations in Poland, emphasising the need for ongoing monitoring and habitat management to mitigate the potential impact of ophidiomycosis.
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Affiliation(s)
- Daniele Marini
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden; (D.M.); (J.R.)
- Department of Veterinary Medicine, University of Perugia, 06126 Perugia, Italy;
| | - Piotr Szczygieł
- Scientific Society of Veterinary Medicine Students, Faculty of Veterinary Medicine, Warsaw University of Life Sciences—SGGW, 02-776 Warsaw, Poland;
| | - Katarzyna Kurek
- Department of Wildlife Conservation, Institute of Nature Conservation Polish Academy of Science, 31-120 Cracow, Poland;
| | - Matteo Riccardo Di Nicola
- Faculty of Veterinary Medicine, Department of Pathobiology, Pharmacology and Zoological Medicine, Wildlife Health Ghent, Ghent University, 9820 Merelbeke, Belgium
- Unit of Dermatology and Cosmetology, IRCCS San Raffaele Hospital, 20132 Milan, Italy
- Asociación Herpetológica Española, 28911 Leganés, Spain
| | - Jean-Lou C. M. Dorne
- Methodology and Scientific Support Unit, European Food Safety Authority (EFSA), 43126 Parma, Italy;
| | | | - Joëlle Rüegg
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden; (D.M.); (J.R.)
| | - Stanisław Bury
- Department of Comparative Anatomy, Institute of Zoology and Biomedical Research, Jagiellonian University, 30-387 Cracow, Poland;
- NATRIX Herpetological Association, 52-010 Wrocław, Poland
| | - Łukasz Kiraga
- Division of Pharmacology and Toxicology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences—SGGW, 02-786 Warsaw, Poland;
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3
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Lastra González D, Nishikawa K, Eto K, Terui S, Kamimura R, Viñuela Rodríguez N, Yoshikawa N, Tominaga A. Lack of variations in the salamander chytrid fungus, Batrachochytrium salamandrivorans, at its alleged origin: Updating its Japanese distribution with new evidence. PLoS One 2024; 19:e0305228. [PMID: 38870137 PMCID: PMC11175521 DOI: 10.1371/journal.pone.0305228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 05/27/2024] [Indexed: 06/15/2024] Open
Abstract
The chytrid fungus Batrachochytrium salamandrivorans [Bsal] is causing declines in the amphibian populations. After a decade of mapping the pathogen in Europe, where it is causing dramatic outbreaks, and North America, where its arrival would affect to the salamander's biodiversity hotspot, little is known about its current status in Asia, from presumably is native. Japan has several species considered as potential carriers, but no regulation is implemented against Bsal spreading. Previous Bsal known presence detected various cases on the Okinawa Island, southwestern Japan. Previous studies on its sister species, B. dendrobatidis presented a high genomic variation in this area and particularly on Cynops ensicauda. Here, we have done the largest monitoring to date in Japan on the Cynops genus, focusing on Okinawa Island and updating its distribution and providing more information to unravel the still unknown origin of Bsal. Interestingly, we have provided revealing facts about different detectability depending on the used molecular techniques and changes in its Japanese distribution. All in all, the Bsal presence in Japan, together with its low variability in the sequenced amplicons, and the lack of apparent mortalities, may indicate that this part of Asia has a high diversity of chytrids.
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Affiliation(s)
- David Lastra González
- Department of Natural Sciences, Faculty of Education, University of the Ryukyus, Nishihara, Okinawa, Japan
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague – Suchdol, Czech Republic
| | - Kanto Nishikawa
- Graduate School of Global Environmental Studies, Kyoto University, Yoshida Hon-machi, Sakyo, Japan
| | - Koshiro Eto
- Kitakyushu Museum of Natural History & Human History, Kitakyushu, Fukuoka, Japan
| | - Shigeharu Terui
- Environment Grasp Promotion Network-PEG, Nonprofit Organization, Kushiro-shi, Hokkaido, Japan
| | - Ryo Kamimura
- Graduate school of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Nuria Viñuela Rodríguez
- Molecular Invertebrate Systematics and Ecology [MISE] Lab, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Natsuhiko Yoshikawa
- Department of Zoology, National Museum of Nature and Science, Tokyo, Tsukuba, Ibaraki, Japan
| | - Atsushi Tominaga
- Department of Natural Sciences, Faculty of Education, University of the Ryukyus, Nishihara, Okinawa, Japan
- Graduate school of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa, Japan
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4
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Böning P, Lötters S, Barzaghi B, Bock M, Bok B, Bonato L, Ficetola GF, Glaser F, Griese J, Grabher M, Leroux C, Munimanda G, Manenti R, Ludwig G, Preininger D, Rödel MO, Seibold S, Smith S, Tiemann L, Thein J, Veith M, Plewnia A. Alpine salamanders at risk? The current status of an emerging fungal pathogen. PLoS One 2024; 19:e0298591. [PMID: 38758948 PMCID: PMC11101120 DOI: 10.1371/journal.pone.0298591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 01/28/2024] [Indexed: 05/19/2024] Open
Abstract
Amphibians globally suffer from emerging infectious diseases like chytridiomycosis caused by the continuously spreading chytrid fungi. One is Batrachochytrium salamandrivorans (Bsal) and its disease ‒ the 'salamander plague' ‒ which is lethal to several caudate taxa. Recently introduced into Western Europe, long distance dispersal of Bsal, likely through human mediation, has been reported. Herein we study if Alpine salamanders (Salamandra atra and S. lanzai) are yet affected by the salamander plague in the wild. Members of the genus Salamandra are highly susceptible to Bsal leading to the lethal disease. Moreover, ecological modelling has shown that the Alps and Dinarides, where Alpine salamanders occur, are generally suitable for Bsal. We analysed skin swabs of 818 individuals of Alpine salamanders and syntopic amphibians at 40 sites between 2017 to 2022. Further, we compiled those with published data from 319 individuals from 13 sites concluding that Bsal infections were not detected. Our results suggest that the salamander plague so far is absent from the geographic ranges of Alpine salamanders. That means that there is still a chance to timely implement surveillance strategies. Among others, we recommend prevention measures, citizen science approaches, and ex situ conservation breeding of endemic salamandrid lineages.
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Affiliation(s)
- Philipp Böning
- Department of Biogeography, Trier University, Trier, Germany
| | - Stefan Lötters
- Department of Biogeography, Trier University, Trier, Germany
| | - Benedetta Barzaghi
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | - Marvin Bock
- Department of Biogeography, Trier University, Trier, Germany
| | - Bobby Bok
- St. Michael College, Zaandam, Netherlands
| | - Lucio Bonato
- Department of Biology, University of Padova, Padova, Italy
- National Biodiversity Future Center, Palermo, Italy
| | | | | | | | | | - Camille Leroux
- Centre d’Ecologie et des Sciences de la Conservation (CESCO), Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Sorbonne Université, Paris, France
- Auddicé Biodiversité–ZAC du Chevalement, Roost-Warendin, France
- Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Gopikrishna Munimanda
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Raoul Manenti
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | | | | | - Mark-Oliver Rödel
- Museum für Naturkunde–Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| | - Sebastian Seibold
- Forest Zoology, Technische Universität Dresden, Tharandt, Germany
- Berchtesgaden National Park, Berchtesgaden, Germany
- Ecosystem Dynamics and Forest Management, Technical University of Munich, Freising, Germany
| | - Steve Smith
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Laura Tiemann
- Department of Neurology, TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Jürgen Thein
- Büro für Faunistik und Umweltbildung, Haßfurt, Germany
| | - Michael Veith
- Department of Biogeography, Trier University, Trier, Germany
| | - Amadeus Plewnia
- Department of Biogeography, Trier University, Trier, Germany
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5
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McGrath-Blaser SE, McGathey N, Pardon A, Hartmann AM, Longo AV. Invasibility of a North American soil ecosystem to amphibian-killing fungal pathogens. Proc Biol Sci 2024; 291:20232658. [PMID: 38628130 PMCID: PMC11021929 DOI: 10.1098/rspb.2023.2658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
North American salamanders are threatened by intercontinental spread of chytridiomycosis, a deadly disease caused by the fungal pathogen Batrachochytrium salamandrivorans (Bsal). To predict potential dispersal of Bsal spores to salamander habitats, we evaluated the capacity of soil microbial communities to resist invasion. We determined the degree of habitat invasibility using soils from five locations throughout the Great Smoky Mountains National Park, a region with a high abundance of susceptible hosts. Our experimental design consisted of replicate soil microcosms exposed to different propagule pressures of the non-native pathogen, Bsal, and an introduced but endemic pathogen, B. dendrobatidis (Bd). To compare growth and competitive interactions, we used quantitative PCR, live/dead cell viability assays, and full-length 16S rRNA sequencing. We found that soil microcosms with intact bacterial communities inhibited both Bsal and Bd growth, but inhibitory capacity diminished with increased propagule pressure. Bsal showed greater persistence than Bd. Linear discriminant analysis (LDA) identified the family Burkolderiaceae as increasing in relative abundance with the decline of both pathogens. Although our findings provide evidence of environmental filtering in soils, such barriers weakened in response to pathogen type and propagule pressure, showing that habitats vary their invasibility based on properties of their local microbial communities.
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Affiliation(s)
| | - Natalie McGathey
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Allison Pardon
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Arik M. Hartmann
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Ana V. Longo
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
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6
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Talavera A, Palmada-Flores M, Burriel-Carranza B, Valbuena-Ureña E, Mochales-Riaño G, Adams DC, Tejero-Cicuéndez H, Soler-Membrives A, Amat F, Guinart D, Carbonell F, Obon E, Marquès-Bonet T, Carranza S. Genomic insights into the Montseny brook newt ( Calotriton arnoldi), a Critically Endangered glacial relict. iScience 2024; 27:108665. [PMID: 38226169 PMCID: PMC10788218 DOI: 10.1016/j.isci.2023.108665] [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: 08/14/2023] [Revised: 10/09/2023] [Accepted: 12/05/2023] [Indexed: 01/17/2024] Open
Abstract
The Montseny brook newt (Calotriton arnoldi), considered the most endangered amphibian in Europe, is a relict salamandrid species endemic to a small massif located in northeastern Spain. Although conservation efforts should always be guided by genomic studies, those are yet scarce among urodeles, hampered by the extreme sizes of their genomes. Here, we present the third available genome assembly for the order Caudata, and the first genomic study of the species and its sister taxon, the Pyrenean brook newt (Calotriton asper), combining whole-genome and ddRADseq data. Our results reveal significant demographic oscillations which accurately mirrored Europe's climatic history. Although severe bottlenecks have led to depauperate genomic diversity and long runs of homozygosity along a gigantic genome, inbreeding might have been avoided by assortative mating strategies. Other life history traits, however, seem to have been less advantageous, and the lack of land dispersal has driven to exceptional levels of population fragmentation.
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Affiliation(s)
- Adrián Talavera
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
| | - Marc Palmada-Flores
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
| | - Bernat Burriel-Carranza
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
- Museu de Ciències Naturals de Barcelona, Pº Picasso s/n, Parc Ciutadella, 08003 Barcelona, Spain
| | | | | | - Dean C. Adams
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50010, USA
| | - Héctor Tejero-Cicuéndez
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
- Department of Biodiversity, Ecology and Evolution, Faculty of Biology, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Anna Soler-Membrives
- Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Fèlix Amat
- Àrea d’Herpetologia, BiBIO, Museu de Granollers – Ciències Naturals. Palaudàries 102, Granollers, Barcelona, Spain
| | - Daniel Guinart
- Servei de Gestió de Parcs Naturals, Diputació de Barcelona, Spain
| | - Francesc Carbonell
- Centre de fauna salvatge de Torreferrussa (Forestal Catalana, SA), Santa Perpètua de Mogoda, Spain
| | - Elena Obon
- Centre de fauna salvatge de Torreferrussa (Forestal Catalana, SA), Santa Perpètua de Mogoda, Spain
| | - Tomàs Marquès-Bonet
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
- Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Salvador Carranza
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
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7
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Porco D, Purnomo CA, Glesener L, Proess R, Lippert S, Jans K, Colling G, Schneider S, Stassen R, Frantz AC. eDNA-based monitoring of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans with ddPCR in Luxembourg ponds: taking signals below the Limit of Detection (LOD) into account. BMC Ecol Evol 2024; 24:4. [PMID: 38178008 PMCID: PMC10768104 DOI: 10.1186/s12862-023-02189-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 12/09/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) are two pathogenic fungi that are a significant threat to amphibian communities worldwide. European populations are strongly impacted and the monitoring of the presence and spread of these pathogens is crucial for efficient decision-making in conservation management. RESULTS Here we proposed an environmental DNA (eDNA) monitoring of these two pathogenic agents through droplet digital PCR (ddPCR) based on water samples from 24 ponds in Luxembourg. In addition, amphibians were swabbed in eight of the targeted ponds in order to compare the two approaches at site-level detection. This study allowed the development of a new method taking below-Limit of Detection (LOD) results into account thanks to the statistical comparison of the frequencies of false positives in no template controls (NTC) and below-LOD results in technical replicates. In the eDNA-based approach, the use of this method led to an increase in Bd and Bsal detection of 28 and 50% respectively. In swabbing, this resulted in 8% more positive results for Bd. In some samples, the use of technical replicates allowed to recover above-LOD signals and increase Bd detection by 35 and 33% respectively for eDNA and swabbing, and Bsal detection by 25% for eDNA. CONCLUSIONS These results confirmed the usefulness of technical replicates to overcome high levels of stochasticity in very low concentration samples even for a highly sensitive technique such as ddPCR. In addition, it showed that below-LOD signals could be consistently recovered and the corresponding amplification events assigned either to positive or negative detection via the method developed here. This methodology might be particularly worth pursuing in pathogenic agents' detection as false negatives could have important adverse consequences. In total, 15 ponds were found positive for Bd and four for Bsal. This study reports the first record of Bsal in Luxembourg.
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Affiliation(s)
- David Porco
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg.
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg.
| | - Chanistya Ayu Purnomo
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Liza Glesener
- Naturschutzsyndikat SICONA, 12, rue de Capellen, L-8393 Olm, Luxembourg, Luxembourg
| | - Roland Proess
- Umweltplanungsbüro Ecotop, 45, Schlassuecht, L-7435 Hollenfels, Luxembourg, Luxembourg
| | - Stéphanie Lippert
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Kevin Jans
- Natur&ëmwelt Fondation Hëllef fir d'Natur, 5, Route de Luxembourg, L-1899, Kockelscheuer, Luxembourg
| | - Guy Colling
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Simone Schneider
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Naturschutzsyndikat SICONA, 12, rue de Capellen, L-8393 Olm, Luxembourg, Luxembourg
| | - Raf Stassen
- Biota.lu, 9a, Rue Principale, L-6990, Hostert, Luxembourg
| | - Alain C Frantz
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg
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8
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Milles A, Banitz T, Bielcik M, Frank K, Gallagher CA, Jeltsch F, Jepsen JU, Oro D, Radchuk V, Grimm V. Local buffer mechanisms for population persistence. Trends Ecol Evol 2023; 38:1051-1059. [PMID: 37558537 DOI: 10.1016/j.tree.2023.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 06/22/2023] [Accepted: 06/29/2023] [Indexed: 08/11/2023]
Abstract
Assessing and predicting the persistence of populations is essential for the conservation and control of species. Here, we argue that local mechanisms require a better conceptual synthesis to facilitate a more holistic consideration along with regional mechanisms known from metapopulation theory. We summarise the evidence for local buffer mechanisms along with their capacities and emphasise the need to include multiple buffer mechanisms in studies of population persistence. We propose an accessible framework for local buffer mechanisms that distinguishes between damping (reducing fluctuations in population size) and repelling (reducing population declines) mechanisms. We highlight opportunities for empirical and modelling studies to investigate the interactions and capacities of buffer mechanisms to facilitate better ecological understanding in times of ecological upheaval.
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Affiliation(s)
- Alexander Milles
- Department of Plant Ecology and Nature Conservation, University of Potsdam, Am Muhlenberg 3, 14476, Potsdam-Golm, Germany; Department of Ecological Modelling, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany; Nationalparkamt Hunsrück-Hochwald, Research, Biotope- and Wildlife Management, Brückener Straße 24, 55765 Birkenfeld, Germany.
| | - Thomas Banitz
- Department of Ecological Modelling, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - Milos Bielcik
- Freie Universität Berlin, Institute of Biology, Altensteinstr. 6, 14195 Berlin, Germany; Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195 Berlin, Germany
| | - Karin Frank
- Department of Ecological Modelling, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany; University of Osnabrück, Institute for Environmental Systems Research, Barbarastr. 12, 49076 Osnabrück, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstr. 4, 04103 Leipzig, Germany
| | - Cara A Gallagher
- Department of Plant Ecology and Nature Conservation, University of Potsdam, Am Muhlenberg 3, 14476, Potsdam-Golm, Germany
| | - Florian Jeltsch
- Department of Plant Ecology and Nature Conservation, University of Potsdam, Am Muhlenberg 3, 14476, Potsdam-Golm, Germany; Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195 Berlin, Germany
| | - Jane Uhd Jepsen
- Department of Arctic Ecology, Norwegian Institute for Nature Research, Fram Centre, Hjalmar Johansens gt.14, 9007 Tromsø, Norway
| | - Daniel Oro
- Centre d'Estudis Avançats de Blanes (CEAB - CSIC), Acces Cala Sant Francesc 14, 17300 Blanes, Girona, Spain.
| | - Viktoriia Radchuk
- Ecological Dynamics Department, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - Volker Grimm
- Department of Plant Ecology and Nature Conservation, University of Potsdam, Am Muhlenberg 3, 14476, Potsdam-Golm, Germany; Department of Ecological Modelling, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstr. 4, 04103 Leipzig, Germany
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9
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Chen G, Lau A, Wan B, Poon ESK, Fung HS, Lee WH, Sung YH, Sin SYW. OCCURRENCE OF PATHOGENIC CHYTRID FUNGI BATRACHOCHYTRIUM SALAMANDRIVORANS AND BATRACHOCHYTRIUM DENDROBATIDIS IN THE HONG KONG NEWT (PARAMESOTRITON HONGKONGENSIS) AND OTHER WILD AND IMPORTED AMPHIBIANS IN A SUBTROPICAL ASIAN REGION. J Wildl Dis 2023; 59:709-721. [PMID: 37768785 DOI: 10.7589/jwd-d-22-00145] [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: 09/27/2022] [Accepted: 05/26/2023] [Indexed: 09/30/2023]
Abstract
One of the major threats for the massive loss in global amphibian diversity is chytridiomycosis, caused by chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Following its discovery in 2013, Bsal has emerged as a severe threat to the global survival of urodelans. In 2018, a study reported a high prevalence of Bsal (65.6%) in the Hong Kong newts (Paramesotriton hongkongensis, Near Threatened) of a southern China population adjacent to Hong Kong (HK). Uncertainty regarding the Bsal infection status of P. hongkongensis inhabiting HK raised deep concern over the risk of introducing Bsal from that population. We screened the skin swabs from wild individuals of P. hongkongensis, 15 sympatric amphibian species, and 16 imported amphibian species in HK for chytrids. We found that both Bsal and Bd occur in low prevalences in P. hongkongensis (Bsal 1.7%, 5/293; Bd 0.34%, 1/293), Hong Kong cascade frog, Amolops hongkongensis, family Ranidae (Bsal only, 5.26%, 1/19), and Asian common toad, Duttaphrynus melanostictus, family Bufonidae (Bsal only, 5.88%, 1/17), populations of HK, with infected individuals being asymptomatic, suggesting a potential role of these species as reservoirs of Bsal. Conversely, Bd, but not Bsal, was present on 13.2% (9/68) of imported amphibians, indicating a high chytrid introduction risk posed by international amphibian trade. Long-term surveillance of the presence of Bd and Bsal in wild and captive amphibians would be advisable, and we recommend that import and export of nonnative chytrid carriers should be prevented, especially to those regions with amphibian populations naïve to Bd and Bsal.
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Affiliation(s)
- Guoling Chen
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, China
| | - Anthony Lau
- Science Unit, Lingnan University, Tuen Mun, Hong Kong, China
| | - Bowen Wan
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, China
| | - Emily Shui Kei Poon
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, China
| | - Hon Shing Fung
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, China
| | - Wing Ho Lee
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, China
| | - Yik-Hei Sung
- Science Unit, Lingnan University, Tuen Mun, Hong Kong, China
| | - Simon Yung Wa Sin
- School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, China
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10
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Erens J, Preissler K, Speybroeck J, Beukema W, Spitzen-van der Sluijs A, Stark T, Laudelout A, Kinet T, Schmidt BR, Martel A, Steinfartz S, Pasmans F. Divergent population responses following salamander mass mortalities and declines driven by the emerging pathogen Batrachochytrium salamandrivorans. Proc Biol Sci 2023; 290:20230510. [PMID: 37752840 PMCID: PMC10523083 DOI: 10.1098/rspb.2023.0510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 08/31/2023] [Indexed: 09/28/2023] Open
Abstract
Understanding wildlife responses to novel threats is vital in counteracting biodiversity loss. The emerging pathogen Batrachochytrium salamandrivorans (Bsal) causes dramatic declines in European salamander populations, and is considered an imminent threat to global amphibian biodiversity. However, real-life disease outcomes remain largely uncharacterized. We performed a multidisciplinary assessment of the longer-term impacts of Bsal on highly susceptible fire salamander (Salamandra salamandra) populations, by comparing four of the earliest known outbreak sites to uninfected sites. Based on large-scale monitoring efforts, we found population persistence in strongly reduced abundances to over a decade after Bsal invasion, but also the extinction of an initially small-sized population. In turn, we found that host responses varied, and Bsal detection remained low, within surviving populations. Demographic analyses indicated an ongoing scarcity of large reproductive adults with potential for recruitment failure, while spatial comparisons indicated a population remnant persisting within aberrant habitat. Additionally, we detected no early signs of severe genetic deterioration, yet nor of increased host resistance. Beyond offering additional context to Bsal-driven salamander declines, results highlight how the impacts of emerging hypervirulent pathogens can be unpredictable and vary across different levels of biological complexity, and how limited pathogen detectability after population declines may complicate surveillance efforts.
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Affiliation(s)
- Jesse Erens
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | | | | | - Wouter Beukema
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
- Reptile, Amphibian & Fish Conservation Netherlands (RAVON), Nijmegen, the Netherlands
| | - Annemarieke Spitzen-van der Sluijs
- Reptile, Amphibian & Fish Conservation Netherlands (RAVON), Nijmegen, the Netherlands
- Institute for Water and Wetland Research, Animal Ecology and Physiology, Radboud University, Nijmegen, the Netherlands
| | - Tariq Stark
- Reptile, Amphibian & Fish Conservation Netherlands (RAVON), Nijmegen, the Netherlands
| | | | | | - Benedikt R. Schmidt
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- Info fauna karch, Neuchâtel, Switzerland
| | - An Martel
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | | | - Frank Pasmans
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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11
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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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12
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Hardman RH, Ammar S, Gerhold R, Sutton W, Carter ED, Snyder S, Neto JDS, Tarkington M, Gray MJ, Miller DL. Coccidiosis in Wild Eastern Newts (Notophthalmus viridescens): An Unexpected Finding in Consecutive Mortality Events in Tennessee, USA. J Wildl Dis 2023; 59:479-486. [PMID: 37179488 DOI: 10.7589/jwd-d-22-00107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/13/2023] [Indexed: 05/15/2023]
Abstract
Wildlife diseases are a major threat for species conservation, and there is a growing need to implement more comprehensive disease response programs to better identify these diseases of concern. During March 2017, we observed moribund and dead eastern newts, Notophthalmus viridescens, in a single pond in middle Tennessee. All moribund individuals were emaciated. We euthanized and processed all individuals immediately on-site and later performed histopathology and quantitative PCR for ranavirus, the protist Perkinsea, and chytrid fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans. One newt was positive for ranavirus. Histopathology showed no evidence of ranavirosis but did reveal overwhelming coccidiosis. Overlapping partial sequences of coccidian 18S subunit DNA showed a 96.4% match with Eimeria steinhausi, suggesting that lesions were due to a previously undescribed Eimeria sp. In 2019, two more moribund newts were encountered at the same pond. Histopathology revealed the same suspicious parasitic organisms, and one individual was positive for B. dendrobatidis. Further research on how seasonal and other environmental parameters may influence coccidia-associated morbidity and mortality is warranted. These events highlight the importance of histopathologic evaluation of mortality events and provide guidance for investigation of future outbreaks.
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Affiliation(s)
- Rebecca H Hardman
- University of Tennessee, Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, 427 Plant Biotechnology Building 2505 E. J. Chapman Dr., Knoxville, Tennessee 37996, USA
- University of Tennessee, College of Veterinary Medicine, Department of Biomedical and Diagnostic Sciences, 2407 River Dr., Knoxville, Tennessee 37996, USA
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 100 8th Ave. SE, St. Petersburg, Florida 33701, USA
| | - Sawsan Ammar
- University of Tennessee, College of Veterinary Medicine, Department of Biomedical and Diagnostic Sciences, 2407 River Dr., Knoxville, Tennessee 37996, USA
- The University of Sadat City, College of Veterinary Medicine, Sadat City, Menofia 32511 Egypt
| | - Richard Gerhold
- University of Tennessee, Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, 427 Plant Biotechnology Building 2505 E. J. Chapman Dr., Knoxville, Tennessee 37996, USA
- University of Tennessee, College of Veterinary Medicine, Department of Biomedical and Diagnostic Sciences, 2407 River Dr., Knoxville, Tennessee 37996, USA
| | - William Sutton
- Wildlife Ecology Laboratory, Tennessee State University, Department of Agricultural and Environmental Sciences, 3500 John A. Merritt Blvd., Farrell-Westbrook Building, Nashville, Tennessee 37209, USA
| | - E Davis Carter
- University of Tennessee, Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, 427 Plant Biotechnology Building 2505 E. J. Chapman Dr., Knoxville, Tennessee 37996, USA
| | - Shawn Snyder
- Wildlife Ecology Laboratory, Tennessee State University, Department of Agricultural and Environmental Sciences, 3500 John A. Merritt Blvd., Farrell-Westbrook Building, Nashville, Tennessee 37209, USA
| | - Jeronimo da Silva Neto
- Wildlife Ecology Laboratory, Tennessee State University, Department of Agricultural and Environmental Sciences, 3500 John A. Merritt Blvd., Farrell-Westbrook Building, Nashville, Tennessee 37209, USA
| | - Meredith Tarkington
- University of Tennessee, Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, 427 Plant Biotechnology Building 2505 E. J. Chapman Dr., Knoxville, Tennessee 37996, USA
| | - Matthew J Gray
- University of Tennessee, Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, 427 Plant Biotechnology Building 2505 E. J. Chapman Dr., Knoxville, Tennessee 37996, USA
| | - Debra L Miller
- University of Tennessee, Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, 427 Plant Biotechnology Building 2505 E. J. Chapman Dr., Knoxville, Tennessee 37996, USA
- University of Tennessee, College of Veterinary Medicine, Department of Biomedical and Diagnostic Sciences, 2407 River Dr., Knoxville, Tennessee 37996, USA
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13
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Sun D, Ellepola G, Herath J, Meegaskumbura M. The two chytrid pathogens of amphibians in Eurasia-climatic niches and future expansion. BMC Ecol Evol 2023; 23:26. [PMID: 37370002 DOI: 10.1186/s12862-023-02132-y] [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: 06/17/2022] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND Climate affects the thermal adaptation and distribution of hosts, and drives the spread of Chytridiomycosis-a keratin-associated infectious disease of amphibians caused by the sister pathogens Batrachochytrium dendrobatidi (Bd) and B. salamandrivorans (Bsal). We focus on their climate-pathogen relationships in Eurasia, the only region where their geographical distributions overlap. Eurasia harbours invaded and native areas of both pathogens and the natural habitats where they co-exist, making it an ideal region to examine their environmental niche correlations. Our understanding of how climate change will affect their distribution is broadened by the differences in climate correlates and niche characteristics between Bd and Bsal in Asia and Europe. This knowledge has potential conservation implications, informing future spread of the disease in different regions. RESULTS We quantified the environmental niche overlap between Bd and Bsal in Eurasia using niche analyses. Results revealed partial overlap in the niche with a unique 4% of non-overlapping values for Bsal, suggesting segregation along certain climate axes. Bd tolerates higher temperature fluctuations, while Bsal requires more stable, lower temperature and wetter conditions. Projections of their Realized Climatic Niches (RCNs) to future conditions show a larger expansion of suitable ranges (SRs) for Bd compared to Bsal in both Asia and Europe, with their centroids shifting in different directions. Notably, both pathogens' highly suitable areas in Asia are expected to shrink significantly, especially under the extreme climate scenarios. In Europe, they are expected to expand significantly. CONCLUSIONS Climate change will impact or increase disease risk to amphibian hosts, particularly in Europe. Given the shared niche space of the two pathogens across available climate gradients, as has already been witnessed in Eurasia with an increased range expansion and niche overlap due to climate change, we expect that regions where Bsal is currently absent but salamanders are present, and where Bd is already prevalent, may be conducive for the spread of Bsal.
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Affiliation(s)
- Dan Sun
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
| | - Gajaba Ellepola
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
- Department of Zoology, Faculty of Science, University of Peradeniya, Peradeniya, Kandy, 20400, Sri Lanka
| | - Jayampathi Herath
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
| | - Madhava Meegaskumbura
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China.
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14
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Gray MJ, Carter ED, Piovia-Scott J, Cusaac JPW, Peterson AC, Whetstone RD, Hertz A, Muniz-Torres AY, Bletz MC, Woodhams DC, Romansic JM, Sutton WB, Sheley W, Pessier A, McCusker CD, Wilber MQ, Miller DL. Broad host susceptibility of North American amphibian species to Batrachochytrium salamandrivorans suggests high invasion potential and biodiversity risk. Nat Commun 2023; 14:3270. [PMID: 37277333 DOI: 10.1038/s41467-023-38979-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 05/22/2023] [Indexed: 06/07/2023] Open
Abstract
Batrachochytrium salamandrivorans (Bsal) is a fungal pathogen of amphibians that is emerging in Europe and could be introduced to North America through international trade or other pathways. To evaluate the risk of Bsal invasion to amphibian biodiversity, we performed dose-response experiments on 35 North American species from 10 families, including larvae from five species. We discovered that Bsal caused infection in 74% and mortality in 35% of species tested. Both salamanders and frogs became infected and developed Bsal chytridiomycosis. Based on our host susceptibility results, environmental suitability conditions for Bsal, and geographic ranges of salamanders in the United States, predicted biodiversity loss is expected to be greatest in the Appalachian Region and along the West Coast. Indices of infection and disease susceptibility suggest that North American amphibian species span a spectrum of vulnerability to Bsal chytridiomycosis and most amphibian communities will include an assemblage of resistant, carrier, and amplification species. Predicted salamander losses could exceed 80 species in the United States and 140 species in North America.
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Affiliation(s)
- Matthew J Gray
- Center for Wildlife Health, School of Natural Resources, University of Tennessee, Knoxville, TN, USA.
| | - Edward Davis Carter
- Center for Wildlife Health, School of Natural Resources, University of Tennessee, Knoxville, TN, USA
| | - Jonah Piovia-Scott
- School of Biological Sciences, Washington State University, Vancouver, WA, USA
| | - J Patrick W Cusaac
- Center for Wildlife Health, School of Natural Resources, University of Tennessee, Knoxville, TN, USA
| | - Anna C Peterson
- Center for Wildlife Health, School of Natural Resources, University of Tennessee, Knoxville, TN, USA
| | - Ross D Whetstone
- Biology Department, University of Massachusetts Boston, Boston, MA, USA
| | - Andreas Hertz
- Biology Department, University of Massachusetts Boston, Boston, MA, USA
| | | | - Molly C Bletz
- Biology Department, University of Massachusetts Boston, Boston, MA, USA
| | - Douglas C Woodhams
- Biology Department, University of Massachusetts Boston, Boston, MA, USA
- Smithsonian Tropical Research Institute, Ancón, Panama
| | - John M Romansic
- School of Biological Sciences, Washington State University, Vancouver, WA, USA
| | - William B Sutton
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, TN, USA
| | - Wesley Sheley
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, USA
| | - Allan Pessier
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, USA
| | | | - Mark Q Wilber
- Center for Wildlife Health, School of Natural Resources, University of Tennessee, Knoxville, TN, USA
| | - Debra L Miller
- Center for Wildlife Health, School of Natural Resources, University of Tennessee, Knoxville, TN, USA
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, USA
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15
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Cavasos K, Poudyal NC, Brunner JL, Warwick AR, Jones J, Moherman N, George M, Willard JD, Brinks ZT, Gray MJ. Attitudes and Behavioral Intentions of Pet Amphibian Owners About Biosecurity Practices. ECOHEALTH 2023; 20:194-207. [PMID: 37486511 DOI: 10.1007/s10393-023-01645-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/28/2023] [Accepted: 04/28/2023] [Indexed: 07/25/2023]
Abstract
Global trade has been linked with the emergence of novel pathogens and declines in amphibian populations worldwide. The potential for pathogen transmission within and between collections of captive amphibians and spillover to wild populations makes it important to understand the motivations, knowledge, attitudes and behaviors of pet amphibian owners. We surveyed US pet amphibian owners to understand their characteristics and evaluated whether and how they were associated with behavioral intentions to adopt biosecurity practices. We found that the majority of pet amphibian owners are aware of the threat of emerging pathogens, concerned about potential spillover of pathogens from captive to wild populations and willing to adopt biosecurity practices to mitigate pathogen threats. Intentions to adopt such practices were driven more by psychosocial constructs such as attitudes, perceptions and beliefs than demographic characteristics. Pet amphibian owners also expressed a strong interest in acquiring, and willingness to pay a price premium for, certified disease-free animals. These findings advance our understanding of the characteristics, motivations and behaviors of pet owners, a key stakeholder in global amphibian trade, which could help to inform new policies and outreach strategies to engage them in mitigating pathogen threats. Moreover, our results imply the economic viability of a market-based program to promote pathogen-free, sustainable trade of amphibians.
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Affiliation(s)
- Kevin Cavasos
- School of Natural Resources, University of Tennessee, Knoxville, TN, 37996, USA
| | - Neelam C Poudyal
- School of Natural Resources, University of Tennessee, Knoxville, TN, 37996, USA.
| | - Jesse L Brunner
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Alexa R Warwick
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, 48824, USA
| | - Joshua Jones
- Pet Advocacy Network, Alexandria, VA, 22314, USA
| | | | | | | | | | - Matthew J Gray
- School of Natural Resources, University of Tennessee, Knoxville, TN, 37996, USA
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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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17
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Auliya M, Altherr S, Nithart C, Hughes A, Bickford D. Numerous uncertainties in the multifaceted global trade in frogs’ legs with the EU as the major consumer. NATURE CONSERVATION 2023. [DOI: 10.3897/natureconservation.51.93868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The commercial trade in frogs and their body parts is global, dynamic and occurs in extremely large volumes (in the thousands of tonnes/yr or billions of frogs/yr). The European Union (EU) remains the single largest importer of frogs’ legs, with most frogs still caught from the wild. Amongst the many drivers of species extinction or population decline (e.g. due to habitat loss, climate change, disease etc.), overexploitation is becoming increasingly more prominent. Due to global declines and extinctions, new attention is being focused on these markets, in part to try to ensure sustainability. While the trade is plagued by daunting realities of data deficiency and uncertainty and the conflicts of commercial interests associated with these data, it is clear is that EU countries are most responsible for the largest portion of the international trade in frogs’ legs of wild species. Over decades of exploitation, the EU imports have contributed to a decline in wild frog populations in an increasing number of supplying countries, such as India and Bangladesh, as well as Indonesia, Turkey and Albania more recently. However, there have been no concerted attempts by the EU and present export countries to ensure sustainability of this trade. Further work is needed to validate species identities, secure data on wild frog populations, establish reasonable monitored harvest/export quotas and disease surveillance and ensure data integrity, quality and security standards for frog farms. Herein, we call upon those countries and their representative governments to assume responsibility for the sustainability of the trade. The EU should take immediate action to channel all imports through a single centralised database and list sensitive species in the Annexes of the EU Wildlife Trade Regulation. Further, listing in CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) can enforce international trade restrictions. More joint efforts are needed to improve regional monitoring schemes before the commercial trade causes irreversible extinctions of populations and species of frogs.
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18
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Hardman RH, Reinert LK, Irwin KJ, Oziminski K, Rollins-Smith L, Miller DL. Disease state associated with chronic toe lesions in hellbenders may alter anti-chytrid skin defenses. Sci Rep 2023; 13:1982. [PMID: 36737574 PMCID: PMC9898527 DOI: 10.1038/s41598-023-28334-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Hellbenders (Cryptobranchus alleganiensis) are large, aquatic salamanders from the eastern United States. Both subspecies, eastern and Ozark hellbenders, have experienced declines resulting in federal listing of Ozark hellbenders. The globally distributed chytrid fungus, Batrachochytrium dendrobatidis (Bd) has been detected in both subspecies, and Batrachochytrium salamandrivorans (Bsal) poses a new threat if introduced into North America. Ozark hellbenders also suffer a high prevalence of toe lesions of unknown etiology, with changes in host immunocompetence hypothesized to contribute. Antimicrobial peptides (AMPs) secreted from dermal granular glands may play a role in hellbender health. We collected skin secretions from free-ranging hellbenders and enriched them for small cationic peptides used for growth inhibition assays against Bd and Bsal. Generalized linear mixed models revealed the presence of active toe lesions as the strongest and only significant predictor of decreased Bd inhibition by skin peptides. We also found skin secretions were more inhibitory of Bsal than Bd. MALDI-TOF mass spectrometry revealed candidate peptides responsible for anti-chytrid activity. Results support the hypothesis that hellbender skin secretions are important for innate immunity against chytrid pathogens, and decreased production or release of skin peptides may be linked to other sub-lethal effects of disease associated with toe lesions.
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Affiliation(s)
- Rebecca H Hardman
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA. .,Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, FL, 33701, USA.
| | - Laura K Reinert
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Kelly J Irwin
- Arkansas Game and Fish Commission, Benton, AR, 72015, USA
| | - Kendall Oziminski
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA
| | - Louise Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Debra L Miller
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA.,School of Natural of Resources, University of Tennessee, Knoxville, Tennessee, 37996, USA
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19
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Plewnia A, Lötters S, Veith M, Peters M, Böning P. Successful Drug-Mediated Host Clearance of Batrachochytrium salamandrivorans. Emerg Infect Dis 2023; 29:411-414. [PMID: 36692470 PMCID: PMC9881767 DOI: 10.3201/eid2902.221162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Skin fungi are among the most dangerous drivers of global amphibian declines, and few mitigation strategies are known. For Batrachochytrium salamandrivorans (Chytridiomycota), available treatments rely on temperature, partially combined with antifungal drugs. We report the clearance of B. salamandrivorans in 2 urodelan species using a solely drug-based approach.
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20
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Davis CL, Muñoz DJ, Amburgey SM, Dinsmore CR, Teitsworth EW, Miller DAW. Multistate model to estimate sex‐specific dispersal rates and distances for a wetland‐breeding amphibian population. Ecosphere 2023. [DOI: 10.1002/ecs2.4345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Courtney L. Davis
- Department of Ecosystem Science and Management Pennsylvania State University University Park Pennsylvania USA
- Intercollege Graduate Ecology Program, Pennsylvania State University University Park Pennsylvania USA
- Cornell Lab of Ornithology Cornell University Ithaca New York USA
| | - David J. Muñoz
- Department of Ecosystem Science and Management Pennsylvania State University University Park Pennsylvania USA
- Intercollege Graduate Ecology Program, Pennsylvania State University University Park Pennsylvania USA
| | - Staci M. Amburgey
- Washington Cooperative Fish and Wildlife Research Unit, School of Aquatic and Fishery Sciences University of Washington Seattle Washington USA
- Washington Department of Fish and Wildlife Olympia Washington USA
| | - Carli R. Dinsmore
- Department of Ecosystem Science and Management Pennsylvania State University University Park Pennsylvania USA
| | - Eric W. Teitsworth
- Department of Fisheries, Wildlife, and Conservation Biology North Carolina State University Raleigh North Carolina USA
| | - David A. W. Miller
- Department of Ecosystem Science and Management Pennsylvania State University University Park Pennsylvania USA
- Intercollege Graduate Ecology Program, Pennsylvania State University University Park Pennsylvania USA
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21
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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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22
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Womack MC, Steigerwald E, Blackburn DC, Cannatella DC, Catenazzi A, Che J, Koo MS, McGuire JA, Ron SR, Spencer CL, Vredenburg VT, Tarvin RD. State of the Amphibia 2020: A Review of Five Years of Amphibian Research and Existing Resources. ICHTHYOLOGY & HERPETOLOGY 2022. [DOI: 10.1643/h2022005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Molly C. Womack
- Department of Biology, Utah State University, Logan, Utah 84322; . ORCID: 0000-0002-3346-021X
| | - Emma Steigerwald
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - David C. Blackburn
- Department of Natural History, Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611; . ORCID: 0000-0002-1810-9886
| | - David C. Cannatella
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712; . ORCID: 0000-0001-8675-0520
| | | | - Jing Che
- State Key Laboratory of Genetic Resources and Evolution & Yunnan Key Laboratory of Biodiversity and Ecological Security of Gaoligong Mountain, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China; . ORCID: 0000-0003-4246-6
| | - Michelle S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Jimmy A. McGuire
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Santiago R. Ron
- Museo de Zoología, Escuela de Biología, Pontificia Universidad Católica del Ecuador, Quito, Ecuador; . ORCID: 0000-0001-6300-9350
| | - Carol L. Spencer
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Vance T. Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
| | - Rebecca D. Tarvin
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California 94720; (ES) ; (MSK) ; (JAM) ; (CS) ; (VTV) ; and (RDT)
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23
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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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24
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Minias P, Palomar G, Dudek K, Babik W. Salamanders reveal novel trajectories of amphibian MHC evolution. Evolution 2022; 76:2436-2449. [PMID: 36000494 DOI: 10.1111/evo.14601] [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: 07/14/2021] [Revised: 07/06/2022] [Accepted: 07/29/2022] [Indexed: 01/22/2023]
Abstract
Genes of the major histocompatibility complex (MHC) code for immune proteins that are crucial for pathogen recognition in vertebrates. MHC research in nonmodel taxa has long been hampered by its genomic complexity that makes the locus-specific genotyping challenging. The recent progress in sequencing and genotyping methodologies allows an extensive phylogenetic coverage in studies of MHC evolution. Here, we analyzed the peptide-binding region of MHC class I (MHC-I) in 30 species of salamanders from six families representative of Urodela phylogeny. This extensive dataset revealed an extreme diversity of MHC-I in salamanders, both in terms of sequence diversity (about 3000 variants) and architecture (2-22 gene copies per species). The signal of positive selection was moderate and consistent between both peptide-binding domains, but varied greatly between genera. Positions of positively selected sites mostly coincided with human peptide-binding sites, suggesting similar structural properties of MHC-I molecules across distant vertebrate lineages. Finally, we provided evidence for the common intraexonic recombination at MHC-I and for the role of life history traits in the processes of MHC-I expansion/contraction. Our study revealed novel evolutionary trajectories of amphibian MHC and it contributes to the understanding of the mechanisms that generated extraordinary MHC diversity throughout vertebrate evolution.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, 90-237, Poland
| | - Gemma Palomar
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, 30-387, Poland.,Parasitology Unit, Department of Biomedicine and Biotechnology, Faculty of Pharmacy, Universidad de Alcalá (UAH), Alcalá de Henares, Madrid, 28805, Spain
| | - Katarzyna Dudek
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, 30-387, Poland
| | - Wiesław Babik
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Kraków, 30-387, Poland
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25
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Ophidiomyces ophidiicola detection and infection: a global review on a potential threat to the world’s snake populations. EUR J WILDLIFE RES 2022. [DOI: 10.1007/s10344-022-01612-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AbstractOphidiomyces ophidiicola (Oo) is one of the most relevant fungal pathogens for snakes. It is the etiological agent of ophidiomycosis, an emerging disease causing dysecdysis, skin abnormalities, crusting cutaneous lesions, and ulcerations. Despite this major tegumentary “tropism”, Oo infection can be systemic and it is capable of inducing visceral lesions. Moreover, ophidiomycosis may lead to abnormalities of reproductive physiology, hunting behavior, and thermoregulation, thus increasing the risks of sublethal effects and predation on affected snakes. Oo seems horizontally transmitted and can induce postnatal mortality. This article reviews published data on Oo detection and infection in all snake species in countries around the world and categorizes these data using new classification parameters. The presence of this fungus has been recorded in 11 states (considering the USA as a whole); however, in four states, the mycosis has only been reported in snakes held in captivity. Detection and/or infection of Oo has been ascertained in 62 snake species, divided into nine families. The taxa have been categorized with diagnostic criteria in order to report, for each species, the highest rank of categorization resulting from all cases. Therefore, 20 species have been included within the class “Ophidiomycosis and Oo shedder”, 11 within “Ophidiomycosis”, 16 in “Apparent ophidiomycosis”, and 15 within “Ophidiomyces ophidiicola present”. We also discuss the significance and limits of case classifications and Oo’s impact on wild populations, and we suggest methods for preliminary surveillance. Standardized methods, interdisciplinary studies, and cooperation between various research institutions may facilitate further Oo screening studies, elucidate the unclear aspects of the disease, and protect ophidiofauna from this emerging threat at the global level.
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26
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Efficacy of Plant-Derived Fungicides at Inhibiting Batrachochytrium salamandrivorans Growth. J Fungi (Basel) 2022; 8:jof8101025. [PMID: 36294589 PMCID: PMC9605044 DOI: 10.3390/jof8101025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/23/2022] [Accepted: 09/27/2022] [Indexed: 11/21/2022] Open
Abstract
The emerging fungal amphibian pathogen, Batrachochytrium salamandrivorans (Bsal), is currently spreading across Europe and given its estimated invasion potential, has the capacity to decimate salamander populations worldwide. Fungicides are a promising in situ management strategy for Bsal due to their ability to treat the environment and infected individuals. However, antifungal drugs or pesticides could adversely affect the environment and non-target hosts, thus identifying safe, effective candidate fungicides for in situ treatment is needed. Here, we estimated the inhibitory fungicidal efficacy of five plant-derived fungicides (thymol, curcumin, allicin, 6-gingerol, and Pond Pimafix®) and one chemical fungicide (Virkon® Aquatic) against Bsal zoospores in vitro. We used a broth microdilution method in 48-well plates to test the efficacy of six concentrations per fungicide on Bsal zoospore viability. Following plate incubation, we performed cell viability assays and agar plate growth trials to estimate the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of each fungicide. All six fungicides exhibited inhibitory and fungicidal effects against Bsal growth, with estimated MIC concentrations ranging from 60 to 0.156 μg/mL for the different compounds. Allicin showed the greatest efficacy (i.e., lowest MIC and MFC) against Bsal zoospores followed by curcumin, Pond Pimafix®, thymol, 6-gingerol, and Virkon® Aquatic, respectively. Our results provide evidence that plant-derived fungicides are effective at inhibiting and killing Bsal zoospores in vitro and may be useful for in situ treatment. Additional studies are needed to estimate the efficacy of these fungicides at inactivating Bsal in the environment and treating Bsal-infected amphibians.
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27
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Moubarak M, Fischhoff IR, Han BA, Castellanos AA. A spatially explicit risk assessment of salamander populations to
Batrachochytrium salamandrivorans
in the United States. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
| | | | - Barbara A. Han
- Cary Institute of Ecosystem Studies Millbrook New York USA
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28
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Torres-Sánchez M, Villate J, McGrath-Blaser S, Longo AV. Panzootic chytrid fungus exploits diverse amphibian host environments through plastic infection strategies. Mol Ecol 2022; 31:4558-4570. [PMID: 35796691 DOI: 10.1111/mec.16601] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 11/29/2022]
Abstract
While some pathogens are limited to single species, others can colonize many hosts, likely contributing to the emergence of novel disease outbreaks. Despite this biodiversity threat, traits associated with host niche expansions are not well understood in multi-host pathogens. Here, we aimed to uncover functional machinery driving multi-host invasion by focusing on Batrachochytrium dendrobatidis (Bd), a pathogen that infects the skin of hundreds of amphibians worldwide. We performed a meta-analysis of Bd gene expression using data from published infection experiments and newly generated profiles. We analyzed Bd transcriptomic landscapes across the skin of 14 host species, reconstructed Bd isolates phylogenetic relationships, and inferred the origin and evolutionary history of differentially expressed genes under a phylogenetic framework comprising other 12 zoosporic fungi. Bd displayed plastic infection strategies when challenged by hosts with different disease susceptibility. Our analyses identified sets of differentially expressed genes under host environments with similar infection outcome. We stressed nutritional immunity and gene silencing as important processes required to overcome challenging skin environments in less susceptible hosts. Overall, Bd genes expressed during amphibian skin exploitation have arisen mainly via gene duplications with great family expansions, increasing the gene copy events previously described for this fungal species. Finally, we provide a comprehensive gene dataset that can be used to further examine eco-evolutionary hypotheses for this host-pathogen system. Our study supports the idea that host environments exert contrasting selective pressures, such that gene expression plasticity could be one of the evolutionary keys leading to the success of multi-host pathogens.
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Affiliation(s)
| | - Jennifer Villate
- Department of Biology, University of Florida, 32611, Gainesville, FL
| | | | - Ana V Longo
- Department of Biology, University of Florida, 32611, Gainesville, FL
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29
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Human impact modulates chytrid fungus occurrence in amphibians in the Brazilian Atlantic Forest. Perspect Ecol Conserv 2022. [DOI: 10.1016/j.pecon.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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30
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Crawshaw L, Buchanan T, Shirose L, Palahnuk A, Cai HY, Bennett AM, Jardine CM, Davy CM. Widespread occurrence of
Batrachochytrium dendrobatidis
in Ontario, Canada, and predicted habitat suitability for the emerging
Batrachochytrium salamandrivorans. Ecol Evol 2022; 12:e8798. [PMID: 35475183 PMCID: PMC9020443 DOI: 10.1002/ece3.8798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 03/06/2022] [Accepted: 03/16/2022] [Indexed: 12/30/2022] Open
Abstract
Chytridiomycosis, caused by the fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, is associated with massive amphibian mortality events worldwide and with some species’ extinctions. Previous ecological niche models suggest that B. dendrobatidis is not well‐suited to northern, temperate climates, but these predictions have often relied on datasets in which northern latitudes are underrepresented. Recent northern detections of B. dendrobatidis suggest that these models may have underestimated the suitability of higher latitudes for this fungus. We used qPCR to test for B. dendrobatidis in 1,041 non‐invasive epithelial swab samples from 18 species of amphibians collected across 735,345 km2 in Ontario and Akimiski Island (Nunavut), Canada. We detected the pathogen in 113 samples (10.9%) from 11 species. Only one specimen exhibited potential clinical signs of disease. We used these data to produce six Species Distribution Models of B. dendrobatidis, which classified half of the study area as potential habitat for the fungus. We also tested each sample for B. salamandrivorans, an emerging pathogen that is causing alarming declines in European salamanders, but is not yet detected in North America. We did not detect B. salamandrivorans in any of the samples, providing a baseline for future surveillance. We assessed the potential risk of future introduction by comparing salamander richness to temperature‐dependent mortality, predicted by a previous exposure study. Areas with the highest species diversity and predicted mortality risk extended 60,530 km2 across southern Ontario, highlighting the potential threat B. salamandrivorans poses to northern Nearctic amphibians. Preventing initial introduction will require coordinated, transboundary regulation of trade in amphibians (including frogs that can carry and disperse B. salamandrivorans), and surveillance of the pathways of introduction (e.g., water and wildlife). Our results can inform surveillance for both pathogens and efforts to mitigate the spread of chytridiomycosis through wild populations.
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Affiliation(s)
- Lauren Crawshaw
- Ontario Ministry of Northern Development, Mines, Natural Resources and Forestry Wildlife Research and Monitoring Section Trent University Peterborough ON Canada
| | - Tore Buchanan
- Ontario Ministry of Northern Development, Mines, Natural Resources and Forestry Wildlife Research and Monitoring Section Trent University Peterborough ON Canada
| | - Leonard Shirose
- Canadian Wildlife Health Cooperative Department of Pathobiology University of Guelph Guelph ON Canada
- Department of Pathobiology University of Guelph Guelph ON Canada
| | - Amanda Palahnuk
- Ontario Ministry of Northern Development, Mines, Natural Resources and Forestry Wildlife Research and Monitoring Section Trent University Peterborough ON Canada
| | - Hugh Y. Cai
- Animal Health Laboratory University of Guelph Guelph ON Canada
| | | | - Claire M. Jardine
- Canadian Wildlife Health Cooperative Department of Pathobiology University of Guelph Guelph ON Canada
- Department of Pathobiology University of Guelph Guelph ON Canada
| | - Christina M. Davy
- Ontario Ministry of Northern Development, Mines, Natural Resources and Forestry Wildlife Research and Monitoring Section Trent University Peterborough ON Canada
- Department of Biology Trent University Peterborough ON Canada
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31
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Lymphocyte Inhibition by the Salamander-Killing Chytrid Fungus, Batrachochytrium salamandrivorans. Infect Immun 2022; 90:e0002022. [PMID: 35130454 PMCID: PMC8929357 DOI: 10.1128/iai.00020-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Amphibian populations have been declining around the world for more than five decades, and the losses continue. Although causes are complex, major contributors to these declines are two chytrid fungi, Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, which both cause the disease termed chytridiomycosis. Previously, we showed that B. dendrobatidis impedes amphibian defenses by directly inhibiting lymphocytes in vitro and in vivo by release of soluble metabolites, including kynurenine (KYN), methylthioadenosine (MTA), and spermidine (SPD). Here, we show that B. salamandrivorans cells and cell-free supernatants also inhibit amphibian lymphocytes as well as a human T cell line. As we have shown for B. dendrobatidis, high-performance liquid chromatography (HPLC) and mass spectrometry revealed that KYN, MTA, and SPD are key metabolites found in the B. salamandrivorans supernatants. Production of inhibitory factors by B. salamandrivorans is limited to mature zoosporangia and can occur over a range of temperatures between 16°C and 26°C. Taken together, these results suggest that both pathogenic Batrachochytrium fungi have evolved similar mechanisms to inhibit lymphocytes in order to evade clearance by the amphibian immune system.
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32
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Hartmann AM, Maddox ML, Ossiboff RJ, Longo AV. Sustained Ranavirus Outbreak Causes Mass Mortality and Morbidity of Imperiled Amphibians in Florida. ECOHEALTH 2022; 19:8-14. [PMID: 35000043 DOI: 10.1007/s10393-021-01572-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
A persistent 2-month long outbreak of Ranavirus in a natural community of amphibians contributed to a mass die-off of gopher frog tadpoles (Lithobates capito) and severe disease in striped newts (Notophthalmus perstriatus) in Florida. Ongoing mortality in L. capito and disease signs in N. perstriatus continued for 5 weeks after the first observation. Hemorrhagic disease and necrosis were diagnosed from pathological examination of L. capito tadpoles. We confirmed detection of a frog virus 3 (FV3)-like Ranavirus via quantitative PCR in all species. Our findings highlight the susceptibility of these species to Rv and the need for long-term disease surveillance during epizootics.
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Affiliation(s)
- Arik M Hartmann
- Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL, 32611, USA.
| | - Max L Maddox
- Department of Wildlife Ecology and Conservation, College of Agriculture and Life Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Robert J Ossiboff
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Ana V Longo
- Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL, 32611, USA
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Sheley WC, Gray MJ, Wilber MQ, Cray C, Carter ED, Miller DL. Electrolyte imbalances and dehydration play a key role in Batrachochytrium salamandrivorans chytridiomycosis. Front Vet Sci 2022; 9:1055153. [PMID: 36713878 PMCID: PMC9880075 DOI: 10.3389/fvets.2022.1055153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Abstract
Introduction One of the most important emerging infectious diseases of amphibians is caused by the fungal pathogen Batrachochytrium salamandrivorans (Bsal). Bsal was recently discovered and is of global concern due to its potential to cause high mortality in amphibians, especially salamander species. To date, little has been reported on the pathophysiological effects of Bsal; however, studies of a similar fungus, B. dendrobatidis (Bd), have shown that electrolyte losses and immunosuppression likely play a key role in morbidity and mortality associated with this disease. The goal of this study was to investigate pathophysiological effects and immune responses associated with Bsal chytridiomycosis using 49 rough-skinned newts (Taricha granulosa) as the model species. Methods Taricha granulosa were exposed to a 1 × 107 per 10 mL dose of Bsal zoospores and allowed to reach various stages of disease progression before being humanely euthanized. At the time of euthanasia, blood was collected for biochemical and hematological analyses as well as protein electrophoresis. Ten standardized body sections were histologically examined, and Bsal-induced skin lesions were counted and graded on a scale of 1-5 based on severity. Results Results indicated that electrolyte imbalances and dehydration induced by damage to the epidermis likely play a major role in the pathogenesis of Bsal chytridiomycosis in this species. Additionally, Bsal-infected, clinically diseased T. granulosa exhibited a systemic inflammatory response identified through alterations in complete blood counts and protein electrophoretograms. Discussion Overall, these results provide foundational information on the pathogenesis of this disease and highlight the differences and similarities between Bsal and Bd chytridiomycosis.
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Affiliation(s)
- Wesley C. Sheley
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, United States
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
- *Correspondence: Wesley C. Sheley
| | - Matthew J. Gray
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - Mark Q. Wilber
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - Carolyn Cray
- Division of Comparative Pathology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - E. Davis Carter
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - Debra L. Miller
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, United States
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
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Cowgill M, Zink AG, Sparagon W, Yap TA, Sulaeman H, Koo MS, Vredenburg VT. Social Behavior, Community Composition, Pathogen Strain, and Host Symbionts Influence Fungal Disease Dynamics in Salamanders. Front Vet Sci 2021; 8:742288. [PMID: 34938792 PMCID: PMC8687744 DOI: 10.3389/fvets.2021.742288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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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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Recknagel H, Trontelj P. From Cave Dragons to Genomics: Advancements in the Study of Subterranean Tetrapods. Bioscience 2021; 72:254-266. [PMID: 35241972 PMCID: PMC8888124 DOI: 10.1093/biosci/biab117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Throughout most of the kingdom Animalia, evolutionary transitions from surface life to a life permanently bound to caves and other subterranean habitats have occurred innumerous times. Not so in tetrapods, where a mere 14 cave-obligate species—all plethodontid and proteid salamanders—are known. We discuss why cave tetrapods are so exceptional and why only salamanders have made the transition. Their evolution follows predictable and convergent, albeit independent pathways. Among the many known changes associated with transitions to subterranean life, eye degeneration, starvation resistance, and longevity are especially relevant to human biomedical research. Recently, sequences of salamander genomes have become available opening up genomic research for cave tetrapods. We discuss new genomic methods that can spur our understanding of the evolutionary mechanisms behind convergent phenotypic change, the relative roles of selective and neutral evolution, cryptic species diversity, and data relevant for conservation such as effective population size and demography.
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Affiliation(s)
- Hans Recknagel
- University of Ljubljana, Slovenia, working, Biotechnical Faculty, Dept. of Biology, Subterranean Biology Lab
| | - Peter Trontelj
- University of Ljubljana, Slovenia, working, Biotechnical Faculty, Dept. of Biology, Subterranean Biology Lab
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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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38
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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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39
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Bletz MC, LaBumbard BC, Le Sage EH, Woodhams DC. Extraction-free detection of amphibian pathogens from water baths. DISEASES OF AQUATIC ORGANISMS 2021; 146:81-89. [PMID: 34617514 DOI: 10.3354/dao03621] [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: 06/13/2023]
Abstract
Detecting and quantifying pathogens with quick, cost-efficient and sensitive methods is needed across disease systems for addressing pertinent epidemiological questions. Typical methods rely on extracting DNA from collected samples. Here we develop and test an extraction-free method from water bath samples that is both sensitive and efficient for 2 major amphibian pathogens-Batrachochytrium dendrobatidis and B. salamandrivorans. We tested mock samples with known pathogen quantities as well as comparatively assessed detection from skin swabs and water baths from field sampled amphibians. Quantitative PCR (qPCR) directly on lyophilized water baths was able to reliably detect low loads of 10 and 1 zoospores for both pathogens, and detection rates were greater than those of swabs from field samples. Further concentration of samples did not improve detection, and collection container type did not influence pathogen load estimates. This method of lyophilization (i.e. freeze-drying) followed by direct qPCR offers an effective and efficient tool from detecting amphibian pathogens, which is crucial for surveillance efforts and estimating shedding rates for robust epidemiological understanding of transmission dynamics. Furthermore, water bath samples have multiple functions and can be used to evaluate mucosal function against pathogens and characterize mucosal components. The multifunctionality of water bath samples and reduced monetary costs and time expenditures make this method an optimal tool for amphibian disease research and may also prove to be useful in other wildlife disease systems.
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Affiliation(s)
- Molly C Bletz
- University of Massachusetts Boston, Department of Biology, 100 Morrissey Blvd, Boston, MA 02125, USA
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40
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Wang Y, Verbrugghe E, Meuris L, Chiers K, Kelly M, Strubbe D, Callewaert N, Pasmans F, Martel A. Epidermal galactose spurs chytrid virulence and predicts amphibian colonization. Nat Commun 2021; 12:5788. [PMID: 34608163 PMCID: PMC8490390 DOI: 10.1038/s41467-021-26127-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/09/2021] [Indexed: 02/08/2023] Open
Abstract
The chytrid fungal pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans cause the skin disease chytridiomycosis in amphibians, which is driving a substantial proportion of an entire vertebrate class to extinction. Mitigation of its impact is largely unsuccessful and requires a thorough understanding of the mechanisms underpinning the disease ecology. By identifying skin factors that mediate key events during the early interaction with B. salamandrivorans zoospores, we discovered a marker for host colonization. Amphibian skin associated beta-galactose mediated fungal chemotaxis and adhesion to the skin and initiated a virulent fungal response. Fungal colonization correlated with the skin glycosylation pattern, with cutaneous galactose content effectively predicting variation in host susceptibility to fungal colonization between amphibian species. Ontogenetic galactose patterns correlated with low level and asymptomatic infections in salamander larvae that were carried over through metamorphosis, resulting in juvenile mortality. Pronounced variation of galactose content within some, but not all species, may promote the selection for more colonization resistant host lineages, opening new avenues for disease mitigation.
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Affiliation(s)
- Yu Wang
- grid.5342.00000 0001 2069 7798Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Elin Verbrugghe
- grid.5342.00000 0001 2069 7798Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Leander Meuris
- grid.5342.00000 0001 2069 7798Center for Medical Biotechnology, Department of Biochemistry and Microbiology, VIB-Ghent University, Zwijnaarde, Belgium
| | - Koen Chiers
- grid.5342.00000 0001 2069 7798Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Moira Kelly
- grid.5342.00000 0001 2069 7798Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Diederik Strubbe
- grid.5342.00000 0001 2069 7798Terrestrial Ecology Unit, Department of Biology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Nico Callewaert
- grid.5342.00000 0001 2069 7798Center for Medical Biotechnology, Department of Biochemistry and Microbiology, VIB-Ghent University, Zwijnaarde, Belgium
| | - Frank Pasmans
- grid.5342.00000 0001 2069 7798Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - An Martel
- grid.5342.00000 0001 2069 7798Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Batrachochytrium salamandrivorans Can Devour More than Salamanders. J Wildl Dis 2021; 57:942-948. [PMID: 34516643 DOI: 10.7589/jwd-d-20-00214] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 03/12/2021] [Indexed: 11/20/2022]
Abstract
Batrachochytrium salamandrivorans is an emerging fungus that is causing salamander declines in Europe. We evaluated whether an invasive frog species (Cuban treefrog, Osteopilus septentrionalis) that is found in international trade could be an asymptomatic carrier when exposed to zoospore doses known to infect salamanders. We discovered that Cuban treefrogs could be infected with B. salamandrivorans and, surprisingly, that chytridiomycosis developed in animals at the two highest zoospore doses. To fulfill Koch's postulates, we isolated B. salamandrivorans from infected frogs, exposed eastern newts (Notophthalmus viridescens) to the isolate, and verified infection and disease by histopathology. This experiment represents the first documentation of B. salamandrivorans chytridiomycosis in a frog species and substantially expands the conservation threat and possible mobilization of this pathogen in trade.
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Sweeny AR, Albery GF, Becker DJ, Eskew EA, Carlson CJ. Synzootics. J Anim Ecol 2021; 90:2744-2754. [PMID: 34546566 DOI: 10.1111/1365-2656.13595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 09/14/2021] [Indexed: 12/30/2022]
Abstract
Ecologists increasingly recognise coinfection as an important component of emergent epidemiological patterns, connecting aspects of ecoimmunology, behaviour, ecosystem function and even extinction risk. Building on syndemic theory in medical anthropology, we propose the term 'synzootics' to describe co-occurring enzootic or epizootic processes that produce worse health outcomes in wild animals. Using framing from syndemic theory, we describe how the synzootic concept offers new insights into the ecology and evolution of infectious diseases. We then recommend a set of empirical criteria and lines of evidence that can be used to identify synzootics in nature. We conclude by exploring how synzootics could indirectly drive the emergence of novel pathogens in human populations.
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Affiliation(s)
- Amy R Sweeny
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Gregory F Albery
- Department of Biology, Georgetown University, Washington, District of Columbia, USA
| | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, Oklahoma, USA
| | - Evan A Eskew
- Department of Biology, Pacific Lutheran University, Tacoma, Washington, USA
| | - Colin J Carlson
- Center for Global Health Science and Security, Georgetown University Medical Center, Georgetown University, Washington, District of Columbia, USA
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Bosch J, Martel A, Sopniewski J, Thumsová B, Ayres C, Scheele BC, Velo-Antón G, Pasmans F. Batrachochytrium salamandrivorans Threat to the Iberian Urodele Hotspot. J Fungi (Basel) 2021; 7:jof7080644. [PMID: 34436183 PMCID: PMC8400424 DOI: 10.3390/jof7080644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/02/2021] [Accepted: 08/05/2021] [Indexed: 12/17/2022] Open
Abstract
The recent introduction of the chytrid fungus Batrachochytrium salamandrivorans into northeastern Spain threatens salamander diversity on the Iberian Peninsula. We assessed the current epidemiological situation with extensive field sampling of urodele populations. We then sought to delineate priority regions and identify conservation units for the Iberian Peninsula by estimating the susceptibility of Iberian urodeles using laboratory experiments, evidence from mortality events in nature and captivity and inference from phylogeny. None of the 1395 field samples, collected between 2015 and 2021 were positive for Bsal and no Bsal-associated mortality events were recorded, in contrast to the confirmed occurrence of Bsal outbreak previously described in 2018. We classified five of eleven Iberian urodele species as highly susceptible, predicting elevated mortality and population declines following potential Bsal emergence in the wild, five species as intermediately susceptible with variable disease outcomes and one species as resistant to disease and mortality. We identified the six conservation units (i.e., species or lineages within species) at highest risk and propose priority areas for active disease surveillance and field biosecurity measures. The magnitude of the disease threat identified here emphasizes the need for region-tailored disease abatement plans that couple active disease surveillance to rapid and drastic actions.
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Affiliation(s)
- Jaime Bosch
- Biodiversity Research Institute (IMIB), University of Oviedo-Principality of Asturias-CSIC, 33600 Mieres, Spain;
- Museo Nacional de Ciencias Naturales-CSIC, 28006 Madrid, Spain
- Correspondence: ; Tel.: +34-6-777-724-02
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, B9820 Merelbeke, Belgium; (A.M.); (F.P.)
| | - Jarrod Sopniewski
- Fenner School of Environment and Society, Australian National University, Canberra 2601, Australia; (J.S.); (B.C.S.)
| | - Barbora Thumsová
- Biodiversity Research Institute (IMIB), University of Oviedo-Principality of Asturias-CSIC, 33600 Mieres, Spain;
- Museo Nacional de Ciencias Naturales-CSIC, 28006 Madrid, Spain
- Asociación Herpetologica Española, 28006 Madrid, Spain;
| | - Cesar Ayres
- Asociación Herpetologica Española, 28006 Madrid, Spain;
| | - Ben C. Scheele
- Fenner School of Environment and Society, Australian National University, Canberra 2601, Australia; (J.S.); (B.C.S.)
| | - Guillermo Velo-Antón
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal;
- Grupo GEA, Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, 36310 Vigo, Spain
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, B9820 Merelbeke, Belgium; (A.M.); (F.P.)
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Fisher MC, Pasmans F, Martel A. Virulence and Pathogenicity of Chytrid Fungi Causing Amphibian Extinctions. Annu Rev Microbiol 2021; 75:673-693. [PMID: 34351790 DOI: 10.1146/annurev-micro-052621-124212] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ancient enzootic associations between wildlife and their infections allow evolution to innovate mechanisms of pathogenicity that are counterbalanced by host responses. However, erosion of barriers to pathogen dispersal by globalization leads to the infection of hosts that have not evolved effective resistance and the emergence of highly virulent infections. Global amphibian declines driven by the rise of chytrid fungi and chytridiomycosis are emblematic of emerging infections. Here, we review how modern biological methods have been used to understand the adaptations and counteradaptations that these fungi and their amphibian hosts have evolved. We explore the interplay of biotic and abiotic factors that modify the virulence of these infections and dissect the complexity of this disease system. We highlight progress that has led to insights into how we might in the future lessen the impact of these emerging infections. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial School of Public Health, Imperial College London, London W2 1PG, United Kingdom;
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
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Mutnale MC, Reddy GS, Vasudevan K. Bacterial Community in the Skin Microbiome of Frogs in a Coldspot of Chytridiomycosis Infection. MICROBIAL ECOLOGY 2021; 82:554-558. [PMID: 33442763 PMCID: PMC8384794 DOI: 10.1007/s00248-020-01669-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/03/2020] [Indexed: 06/12/2023]
Abstract
Chytridiomycosis is a fungal disease caused by the pathogens, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), which has caused declines in amphibian populations worldwide. Asia is considered as a coldspot of infection, since adult frogs are less susceptible to Bd-induced mortality or morbidity. Using the next-generation sequencing approach, we assessed the cutaneous bacterial community composition and presence of anti-Bd bacteria in six frog species from India using DNA isolated from skin swabs. All the six frog species sampled were tested using nested PCR and found Bd negative. We found a total of 551 OTUs on frog skin, of which the bacterial phyla such as Proteobacteria (56.15% average relative abundance) was dominated followed by Actinobacteria (21.98% average relative abundance) and Firmicutes (13.7% average relative abundance). The contribution of Proteobacteria in the anti-Bd community was highest and represented by 175 OTUs. Overall, the anti-Bd bacterial community dominated (51.7% anti-Bd OTUs) the skin microbiome of the frogs. The study highlights the putative role of frog skin microbiome in affording resistance to Bd infections in coldspots of infection.
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Affiliation(s)
- Milind C Mutnale
- Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Gundlapally S Reddy
- Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Karthikeyan Vasudevan
- Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India.
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ABSENCE OF BATRACHOCHYTRIUM SALAMANDRIVORANS IN A GLOBAL HOTSPOT FOR SALAMANDER BIODIVERSITY. J Wildl Dis 2021; 57:553-560. [PMID: 33984856 DOI: 10.7589/jwd-d-20-00218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/08/2021] [Indexed: 11/20/2022]
Abstract
Batrachochytrium salamandrivorans (Bsal) is an emerging fungal pathogen that affects salamander and newt populations in Asia and Europe. In the Western Hemisphere, Bsal represents a major threat to endemic amphibian populations, which have not evolved resistance to infection, and which could experience local extinction events such as those observed in European fire salamanders (Salamandra salamandra). We report findings of a survey focusing specifically on wild lungless salamanders in the southeastern US, the most biodiverse location for salamander species globally. Between May 2016 and July 2018, we conducted 25 surveys at 10 sites across three ecoregions in Tennessee, US. Using quantitative (q)PCR, we screened water samples and skin swabs from 137 salamanders in five plethodontid genera. Although single replicates of six samples amplified during qPCR cycling, no samples could be confirmed as positive for the presence of Bsal with 28S rRNA PCR and independent laboratory screening. It is probable that we found false positive results, as reported by other researchers using the same assay. We offer recommendations for future monitoring efforts.
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Beukema W, Erens J, Schulz V, Stegen G, Spitzen-van der Sluijs A, Stark T, Laudelout A, Kinet T, Kirschey T, Poulain M, Miaud C, Steinfartz S, Martel A, Pasmans F. Landscape epidemiology of Batrachochytrium salamandrivorans: reconciling data limitations and conservation urgency. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02342. [PMID: 33817953 DOI: 10.1002/eap.2342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 12/01/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Starting in 2010, rapid fire salamander (Salamandra salamandra) population declines in northwestern Europe heralded the emergence of Batrachochytrium salamandrivorans (Bsal), a salamander-pathogenic chytrid fungus. Bsal poses an imminent threat to global salamander diversity owing to its wide host range, high pathogenicity, and long-term persistence in ecosystems. While there is a pressing need to develop further research and conservation actions, data limitations inherent to recent pathogen emergence obscure necessary insights into Bsal disease ecology. Here, we use a hierarchical modeling framework to describe Bsal landscape epidemiology of outbreak sites in light of these methodological challenges. Using model selection and machine learning, we find that Bsal presence is associated with humid and relatively cool, stable climates. Outbreaks are generally located in areas characterized by low landscape heterogeneity and low steepness of slope. We further find an association between Bsal presence and high trail density, suggesting that human-mediated spread may increase risk for spillover between populations. We then use distribution modeling to show that favorable conditions occur in lowlands influenced by the North Sea, where increased survey effort is needed to determine how Bsal impacts local newt populations, but also in hill- and mountain ranges in northeastern France and the lower half of Germany. Finally, connectivity analyses suggest that these hill- and mountain ranges may act as stepping stones for further spread southward. Our results provide initial insight into regional environmental conditions underlying Bsal epizootics, present updated invasibility predictions for northwestern Europe, and lead us to discuss a wide variety of potential survey and research actions needed to advance future conservation and mitigation efforts.
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Affiliation(s)
- Wouter Beukema
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
- Naturalis Biodiversity Center, P.O. Box␣9517, Leiden, 2300RA, the Netherlands
| | - Jesse Erens
- Naturalis Biodiversity Center, P.O. Box␣9517, Leiden, 2300RA, the Netherlands
| | - Vanessa Schulz
- Molecular Evolution and Systematics of Animals, Institute of Biology, University of Leipzig, Talstrasse 33, Leipzig, 04103, Germany
- Technische Universität Braunschweig, Division of Evolutionary Biology, Zoological Institute, Mendelssohnstrasse 4, Braunschweig, 38106, Germany
| | - Gwij Stegen
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | | | - Tariq Stark
- Reptile, Amphibian & Fish Conservation Netherlands (RAVON), Toernooiveld 1, Nijmegen, 6525ED, the Netherlands
| | - Arnaud Laudelout
- Reptile, Amphibian & Fish Conservation Netherlands (RAVON), Toernooiveld 1, Nijmegen, 6525ED, the Netherlands
| | - Thierry Kinet
- Natagora, Traverse des Muses 1, Namur, 5000, Belgium
| | - Tom Kirschey
- Nature and Biodiversity Conservation Union (NABU), Charitéstrasse 3, Berlin, 10117, Germany
| | - Marie Poulain
- Biogeography and Vertebrate Ecology, CEFE, EPHE-PSL, CNRS, University of Montpellier, Paul Valéry University Montpellier III, 1919 route de Mende, Montpellier, 34293, France
| | - Claude Miaud
- Biogeography and Vertebrate Ecology, CEFE, EPHE-PSL, CNRS, University of Montpellier, Paul Valéry University Montpellier III, 1919 route de Mende, Montpellier, 34293, France
| | - Sebastian Steinfartz
- Molecular Evolution and Systematics of Animals, Institute of Biology, University of Leipzig, Talstrasse 33, Leipzig, 04103, Germany
| | - An Martel
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Frank Pasmans
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
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Bozzuto C, Canessa S, Koella JC. Exploring artificial habitat fragmentation to control invasion by infectious wildlife diseases. Theor Popul Biol 2021; 141:14-23. [PMID: 34139201 DOI: 10.1016/j.tpb.2021.06.001] [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: 01/21/2020] [Revised: 05/26/2021] [Accepted: 06/01/2021] [Indexed: 10/21/2022]
Abstract
One way to reduce the impacts of invading wildlife diseases is setting up fences that would reduce the spread of pathogens by limiting connectivity, similarly to exclusion fences that are commonly used to conserve threatened species against invasive predators. One of the problems with fences is that, while they may have the short-term benefit of impeding the spread of disease, this benefit may be offset by potential long-term ecological costs of fragmentation by fencing. However, managers facing situations where a pathogen has been detected near the habitat of a (highly) vulnerable species may be willing to explore such a trade-off. To aid such exploration quantitatively, we present a series of models trading off the benefits of fragmentation (potential reduction of disease impacts on susceptible individuals) against its costs (both financial and ecological, i.e. reduced viability in the patches created by fragmentation), and exploring the effects of fragmentation on non-target species richness. For all model variants we derive the optimal number of artificial patches. We show that pre-emptive disease fences may have benefits when the risk of disease exceeds the impacts of fragmentation, when fence failure rates are lower than a specific threshold, and when sufficient resources are available to implement optimal solutions. A useful step to initiate planning is to obtain information about the expected number of initial infection events and on the host's extinction threshold with respect to the focal habitat and management duration. Our approach can assist managers to identify whether the trade-offs support the decision to fence and how intensive fragmentation should be.
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Affiliation(s)
- Claudio Bozzuto
- Wildlife Analysis GmbH, Oetlisbergstrasse 38, 8053 Zurich, Switzerland.
| | - Stefano Canessa
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Jacob C Koella
- Laboratory of ecology and epidemiology of parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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Connectivity of Alpine newt populations (Ichthyosaura alpestris) exacerbates the risk of Batrachochytrium salamandrivorans outbreaks in European fire salamanders (Salamandra salamandra). CONSERV GENET 2021. [DOI: 10.1007/s10592-021-01377-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractThe pathogenic chytrid fungus Batrachochytrium salamandrivorans (Bsal) was introduced from Asia to Europe, most likely via the pet trade. It is currently causing a severe local decline in populations of the European fire salamanders (Salamandra salamandra). Laboratory tests confirmed that all infected individuals succumbed to the disease within two weeks. Furthermore, mass mortality events in the wild were observed in Germany, Belgium and the Netherlands. Some newt species, including the Alpine newt (Ichthyosaura alpestris), can also become infected with Bsal. However, they seem to be ‘tolerant’ and can often survive the disease, but maintain an infectious load, which they could spread among connected populations. It is, therefore, hypothesized that this species functions as a vector of the disease and threatens syntopic populations of susceptible species such as the European fire salamander. To assess the risk of Alpine newts as vectors for Bsal, we sampled 233 individuals from 50 sites in 2017 and performed a genetic population connectivity analysis using microsatellites. The results showed that populations of Alpine newts are not spatially structured, suggesting high gene flow across the study area. Tests for Bsal of all Alpine newts and 150 individuals of two other newt species confirmed five infected individuals. Infected newts can thus function as reservoirs and vectors of Bsal and spread it through dispersal. As a result, the risk of European fire salamander declines in this region is further exacerbated by the connectivity of syntopic Alpine newt populations.
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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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