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Rollins-Smith LA, Le Sage EH. Batrachochytrium fungi: stealth invaders in amphibian skin. Curr Opin Microbiol 2021; 61:124-132. [PMID: 33964650 DOI: 10.1016/j.mib.2021.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/07/2021] [Accepted: 04/15/2021] [Indexed: 10/21/2022]
Abstract
Amphibian populations around the world have been affected by two pathogenic fungi within the phylum Chytridiomycota. Batrachochytrium dendrobatidis (Bd) has infected hundreds of species and led to widespread declines and some species extinctions. Batrachochytrium salamandrivorans (Bsal) has devastated some native European salamanders, especially the iconic fire salamanders (Salamandra salamandra). Comparative genomic studies show that Bd is more diverse and widespread than previously thought, and global lineages occur together allowing for the development of hybrid lineages. New studies raise the concern of greater pathogenesis if both Bd and Bsal infect the same host. Although amphibians possess robust immune defenses, co-infected and many single-infected hosts seem unable to mount effective immune responses. A strong defense may actually be harmful. Analysis of Bd and Bsal secretions documents small metabolites that signal high density to limit their growth and to suppress adaptive immune defenses, thus enabling a stealth presence in the skin compartment.
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Affiliation(s)
- Louise A Rollins-Smith
- Departments of Pathology, Microbiology and Immunology and of Pediatrics, Vanderbilt University School of Medicine and Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA.
| | - Emily H Le Sage
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
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Plethodontid salamanders show variable disease dynamics in response to Batrachochytrium salamandrivorans chytridiomycosis. Biol Invasions 2021. [DOI: 10.1007/s10530-021-02536-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Borzée A, Kielgast J, Wren S, Angulo A, Chen S, Magellan K, Messenger KR, Hansen-Hendrikx CM, Baker A, Santos MMD, Kusrini M, Jiang J, Maslova IV, Das I, Park D, Bickford D, Murphy RW, Che J, Van Do T, Nguyen TQ, Chuang MF, Bishop PJ. Using the 2020 global pandemic as a springboard to highlight the need for amphibian conservation in eastern Asia. BIOLOGICAL CONSERVATION 2021; 255:108973. [PMID: 35125500 PMCID: PMC8798316 DOI: 10.1016/j.biocon.2021.108973] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/28/2020] [Accepted: 01/11/2021] [Indexed: 05/26/2023]
Abstract
UNLABELLED Emerging infectious diseases are on the rise in many different taxa, including, among others, the amphibian batrachochytrids, the snake fungal disease and the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) virus, responsible for Coronavirus disease 2019 (COVID-19) in mammals. Following the onset of the pandemic linked to COVID-19, eastern Asia has shown strong leadership, taking actions to regulate the trade of potential vector species in several regions. These actions were taken in response to an increase in public awareness, and the need for a quick reaction to mitigate against further pandemics. However, trade restrictions rarely affect amphibians, despite the risk of pathogen transmission, directly, or indirectly through habitat destruction and the loss of vector consumption. Thus, species that help alleviate the risk of zoonoses or provide biological control are not protected. Hence, in view of the global amphibian decline and the risk of zoonoses, we support the current wildlife trade regulations and support measures to safeguard wildlife from overexploitation. The current period of regulation overhaul should be used as a springboard for amphibian conservation. To mitigate risks, we suggest the following stipulations specifically for amphibians. I) Restrictions to amphibian farming in eastern Asia, in relation to pathogen transmission and the establishment of invasive species. II) Regulation of the amphibian pet trade, with a focus on potential vector species. III) Expansion of the wildlife trade ban, to limit the wildlife-human-pet interface. The resulting actions will benefit both human and wildlife populations, as they will lead to a decrease in the risk of zoonoses and better protection of the environment. SIGNIFICANCE STATEMENT There is an increasing number of emerging infectious diseases impacting all species, including amphibians, reptiles and mammals. The latest threat to humans is the virus responsible for COVID-19, and the resulting pandemic. Countries in eastern Asia have taken steps to regulate wildlife trade and prevent further zoonoses thereby decreasing the risk of pathogens arising from wild species. However, as amphibians are generally excluded from regulations we support specific trade restrictions: I) Restrictions to amphibian farming; II) regulation of the amphibian pet trade; III) expansion of the wildlife trade ban. These restrictions will benefit both human and wildlife populations by decreasing the risks of zoonoses and better protecting the environment.
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Affiliation(s)
- Amaël Borzée
- Laboratory of Animal Behaviour and Conservation, College of Biology and the Environment, Nanjing Forestry University, Nanjing, People's Republic of China
- IUCN SSC Amphibian Specialist Group, 3701 Lake Shore Blvd W, P.O. Box 48586, Toronto, Ontario M8W 1P5, Canada
| | - Jos Kielgast
- IUCN SSC Amphibian Specialist Group, 3701 Lake Shore Blvd W, P.O. Box 48586, Toronto, Ontario M8W 1P5, Canada
- Section for Freshwater Biology, Department of Biology, University of Copenhagen, Universitetsparken 4, DK-2100, Denmark
- Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, Universitetsparken, 15, DK-2100, Denmark
| | - Sally Wren
- IUCN SSC Amphibian Specialist Group, 3701 Lake Shore Blvd W, P.O. Box 48586, Toronto, Ontario M8W 1P5, Canada
- Department of Zoology, University of Otago, 340 Great King Street, Dunedin 9016, New Zealand
| | - Ariadne Angulo
- IUCN SSC Amphibian Specialist Group, 3701 Lake Shore Blvd W, P.O. Box 48586, Toronto, Ontario M8W 1P5, Canada
| | - Shu Chen
- Zoological Society of London, London NW1 4RY, United Kingdom
| | | | - Kevin R Messenger
- Herpetology and Applied Conservation Laboratory, College of Biology and the Environment, Nanjing Forestry University, Nanjing, People's Republic of China
| | | | - Anne Baker
- Amphibian Ark, Conservation Planning Specialist Group, Apple Valley, USA
| | - Marcileida M Dos Santos
- IUCN SSC Amphibian Specialist Group, 3701 Lake Shore Blvd W, P.O. Box 48586, Toronto, Ontario M8W 1P5, Canada
- Department of Zoology, University of Otago, 340 Great King Street, Dunedin 9016, New Zealand
| | - Mirza Kusrini
- Department of Forest Resources Conservation and Ecotourism, IPB University, Bogor, Indonesia
| | - Jianping Jiang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
| | - Irina V Maslova
- Federal Scientific Center of the East Asia Terrestrial Biodiversity Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - Indraneil Das
- Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan 94300, Malaysia
| | - Daesik Park
- Division of Science Education, Kangwon National University, Chuncheon, Kangwon 24341, Republic of Korea
| | | | - Robert W Murphy
- Centre for Biodiversity, Royal Ontario Museum, Toronto, Canada
| | - Jing Che
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, People's Republic of China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, People's Republic of China
| | - Tu Van Do
- Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Viet Nam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Viet Nam
| | - Truong Quang Nguyen
- Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Viet Nam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Viet Nam
| | - Ming-Feng Chuang
- Department of Life Sciences and Research Center for Global Change Biology, National Chung Hsing University, Taichung, Taiwan
| | - Phillip J Bishop
- IUCN SSC Amphibian Specialist Group, 3701 Lake Shore Blvd W, P.O. Box 48586, Toronto, Ontario M8W 1P5, Canada
- Department of Zoology, University of Otago, 340 Great King Street, Dunedin 9016, New Zealand
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Range-wide decline of Chinese giant salamanders Andrias spp. from suitable habitat. ORYX 2021. [DOI: 10.1017/s0030605320000411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
AbstractOver recent decades, Chinese giant salamanders Andrias spp. have declined dramatically across much of their range. Overexploitation and habitat degradation have been widely cited as the cause of these declines. To investigate the relative contribution of each of these factors in driving the declines, we carried out standardized ecological and questionnaire surveys at 98 sites across the range of giant salamanders in China. We did not find any statistically significant differences between water parameters (temperature, dissolved oxygen, ammonia, nitrite, nitrate, salinity, alkalinity, hardness and flow rate) recorded at sites where giant salamanders were detected by survey teams and/or had been recently seen by local respondents, and sites where they were not detected and/or from which they had recently been extirpated. Additionally, we found direct and indirect evidence that the extraction of giant salamanders from the wild is ongoing, including within protected areas. Our results support the hypothesis that the decline of giant salamanders across China has been primarily driven by overexploitation. Data on water parameters may be informative for the establishment of conservation breeding programmes, an initiative recommended for the conservation of these species.
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Tompros A, Dean AD, Fenton A, Wilber MQ, Carter ED, Gray MJ. Frequency-dependent transmission of Batrachochytrium salamandrivorans in eastern newts. Transbound Emerg Dis 2021; 69:731-741. [PMID: 33617686 PMCID: PMC9290712 DOI: 10.1111/tbed.14043] [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: 12/07/2020] [Revised: 02/11/2021] [Accepted: 02/19/2021] [Indexed: 12/25/2022]
Abstract
Transmission is the fundamental process whereby pathogens infect their hosts and spread through populations, and can be characterized using mathematical functions. The functional form of transmission for emerging pathogens can determine pathogen impacts on host populations and can inform the efficacy of disease management strategies. By directly measuring transmission between infected and susceptible adult eastern newts (Notophthalmus viridescens) in aquatic mesocosms, we identified the most plausible transmission function for the emerging amphibian fungal pathogen Batrachochytrium salamandrivorans (Bsal). Although we considered a range of possible transmission functions, we found that Bsal transmission was best explained by pure frequency dependence. We observed that >90% of susceptible newts became infected within 17 days post‐exposure to an infected newt across a range of host densities and initial infection prevalence treatments. Under these conditions, we estimated R0 = 4.9 for Bsal in an eastern newt population. Our results suggest that Bsal has the capability of driving eastern newt populations to extinction and that managing host density may not be an effective management strategy. Intervention strategies that prevent Bsal introduction or increase host resistance or tolerance to infection may be more effective. Our results add to the growing empirical evidence that transmission of wildlife pathogens can saturate and be functionally frequency‐dependent.
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Affiliation(s)
- Adrianna Tompros
- Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, USA
| | - Andrew D Dean
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Andy Fenton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Mark Q Wilber
- Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, USA.,Department of Ecology, Evolution and Marine Biology, University of California-Santa Barbara, Santa Barbara, CA, USA
| | - Edward Davis Carter
- Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, USA
| | - Matthew J Gray
- Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, USA
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56
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Winter is coming-Temperature affects immune defenses and susceptibility to Batrachochytrium salamandrivorans. PLoS Pathog 2021; 17:e1009234. [PMID: 33600433 PMCID: PMC7891748 DOI: 10.1371/journal.ppat.1009234] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 12/08/2020] [Indexed: 12/24/2022] Open
Abstract
Environmental temperature is a key factor driving various biological processes, including immune defenses and host-pathogen interactions. Here, we evaluated the effects of environmental temperature on the pathogenicity of the emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal), using controlled laboratory experiments, and measured components of host immune defense to identify regulating mechanisms. We found that adult and juvenile Notophthalmus viridescens died faster due to Bsal chytridiomycosis at 14°C than at 6 and 22°C. Pathogen replication rates, total available proteins on the skin, and microbiome composition likely drove these relationships. Temperature-dependent skin microbiome composition in our laboratory experiments matched seasonal trends in wild N. viridescens, adding validity to these results. We also found that hydrophobic peptide production after two months post-exposure to Bsal was reduced in infected animals compared to controls, perhaps due to peptide release earlier in infection or impaired granular gland function in diseased animals. Using our temperature-dependent susceptibility results, we performed a geographic analysis that revealed N. viridescens populations in the northeastern United States and southeastern Canada are at greatest risk for Bsal invasion, which shifted risk north compared to previous assessments. Our results indicate that environmental temperature will play a key role in the epidemiology of Bsal and provide evidence that temperature manipulations may be a viable disease management strategy. In 2010, a new skin-eating fungus, Batrachochytrium salamandrivorans (Bsal), was discovered killing salamanders in the Netherlands. Since then, the pathogen has spread to other European countries. Bsal is believed to be from Asia and is being translocated through the international trade of amphibians. To our knowledge, Bsal has not arrived to North America. As a proactive strategy for disease control, we evaluated how a range of environmental temperatures in North America could affect invasion risk of Bsal into a widely distributed salamander species, the eastern newt (Notophthalmus viridescens). Our results show that northeastern USA, southeastern Canada, and the higher elevations of the Appalachian Mountains have the greatest likelihood of Bsal invasion, when temperature-dependent susceptibility is included in risk analyses. Changes in eastern newt susceptibility to Bsal infection associated with temperature are likely an interaction between pathogen replication rate and host immune defenses, including changes in skin microbiome composition and the host’s ability to produce Bsal-killing proteins on the skin. Our study provides new insights into how latitude, elevation and season can impact the epidemiology of Bsal, and suggests that strategies that manipulate microclimate of newt habitats could be useful in managing Bsal outbreaks and that climate change will impact Bsal invasion probability.
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Yannic G, Helfer V, Sermier R, Schmidt BR, Fumagalli L. Fine scale genetic structure in fire salamanders (Salamandra salamandra) along a rural-to-urban gradient. CONSERV GENET 2021. [DOI: 10.1007/s10592-021-01335-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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58
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Wilber MQ, Carter ED, Gray MJ, Briggs CJ. Putative resistance and tolerance mechanisms have little impact on disease progression for an emerging salamander pathogen. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Mark Q. Wilber
- Department of Ecology Evolution and Marine Biology University of California Santa Barbara CA USA
- Center for Wildlife Health Department of Forestry, Wildlife and Fisheries University of Tennessee Institute of Agriculture Knoxville TN USA
| | - Edward Davis Carter
- Center for Wildlife Health Department of Forestry, Wildlife and Fisheries University of Tennessee Institute of Agriculture Knoxville TN USA
| | - Matthew J. Gray
- Center for Wildlife Health Department of Forestry, Wildlife and Fisheries University of Tennessee Institute of Agriculture Knoxville TN USA
| | - Cheryl J. Briggs
- Department of Ecology Evolution and Marine Biology University of California Santa Barbara CA USA
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59
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Pereira KE, Woodley SK. Skin defenses of North American salamanders against a deadly salamander fungus. Anim Conserv 2021. [DOI: 10.1111/acv.12666] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- K. E. Pereira
- Department of Biological Sciences Duquesne University Pittsburgh PA USA
| | - S. K. Woodley
- Department of Biological Sciences Duquesne University Pittsburgh PA USA
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60
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Islam MR, Gray MJ, Peace A. Identifying the Dominant Transmission Pathway in a Multi-stage Infection Model of the Emerging Fungal Pathogen Batrachochytrium Salamandrivorans on the Eastern Newt. INFECTIOUS DISEASES AND OUR PLANET 2021. [DOI: 10.1007/978-3-030-50826-5_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Burns TJ, Scheele BC, Brannelly LA, Clemann N, Gilbert D, Driscoll DA. Indirect terrestrial transmission of amphibian chytrid fungus from reservoir to susceptible host species leads to fatal chytridiomycosis. Anim Conserv 2020. [DOI: 10.1111/acv.12665] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas J. Burns
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University (Burwood Campus) Geelong Vic. Australia
| | - Ben C. Scheele
- Fenner School of Environment and Society Australian National University Canberra ACT Australia
| | - Laura A. Brannelly
- Melbourne Veterinary School Faculty of Veterinary and Agricultural Sciences University of Melbourne Werribee Vic. Australia
| | - Nick Clemann
- Department of Environment, Land, Water and Planning Arthur Rylah Institute for Environmental Research Heidelberg Vic. Australia
| | - Deon Gilbert
- Wildlife Conservation and Science. Zoos Victoria Parkville Vic. Australia
| | - Don A. Driscoll
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University (Burwood Campus) Geelong Vic. Australia
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Oswald P, Rodríguez A, Bourke J, Wagner N, de Buhr N, Buschmann H, Köckritz-Blickwede MV, Pröhl H. Locality, time and heterozygosity affect chytrid infection in yellow-bellied toads. DISEASES OF AQUATIC ORGANISMS 2020; 142:225-237. [PMID: 33331290 DOI: 10.3354/dao03543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The chytrid fungus Batrachochytrium dendrobatidis (Bd) infects numerous amphibian species worldwide and is suggested to drive population declines and extinction events. We report a study of Bd infection at the northernmost distribution of the European yellow-bellied toad Bombina variegata. A total of 577 individuals from ponds in 16 study sites were sampled for DNA and Bd throughout the breeding season. Microsatellite genotyping revealed 3 genetic clusters for the host B. variegata with an overall low genetic diversity. One of the clusters displayed a low microsatellite heterozygosity, a high inbreeding coefficient as well as high Bd infection prevalence and intensities. Multi-model estimates identified site, time of sampling, and heterozygosity to be important predictors of an individual's Bd infection status, and identified a strong effect of site on individual Bd infection intensity. The study site effects are suggestive of localized infection peaks, and the increase of individual Bd infection probabilities towards the end of the sampling period suggests cumulative infection during the breeding season. This study highlights the need for regular monitoring of Bd infection variables at multiple localities and times to gain insights into Bd dynamics. Due to the detected relationship between individual Bd infection status and heterozygosity, conservation measures should focus on the maintenance of high genetic diversity and connectivity within and among amphibian populations.
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Affiliation(s)
- Pia Oswald
- Institute of Zoology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
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Lastra González D, Baláž V, Chajma P, Vojar J. Surveying for Batrachochytrium salamandrivorans presence in Spanish captive collections of amphibians. DISEASES OF AQUATIC ORGANISMS 2020; 142:99-103. [PMID: 33269721 DOI: 10.3354/dao03535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Batrachochytrium salamandrivorans (Bsal), a pathogenic fungus causing the fatal disease chytridiomycosis in amphibians, was likely introduced to Europe through the trade in pet salamanders from Asia and then escaped into wild populations. Among European countries, Spain has a large number of private breeders and keepers of pet salamanders, and cases of Bsal in wild and captive populations already have been confirmed there. However, surveillance for the pathogen in Spanish collections of amphibians is sparse. Therefore, assisted by private owners and breeders, we surveyed 10 amphibian collections and analysed a total of 317 samples for presence of Bsal. All of our analyses yielded negative results. However, this apparent lack of Bsal cases in captivity should not encourage relaxation of vigilance, quarantine efforts or good practices. Because amphibian collections represent highly dynamic environments (animals are coming in and out), the pathogen could easily be introduced into a collection by new individuals. Any case of Bsal infection in captive animals could lead to its further spread to wild populations of susceptible species, potentially decimating them, and thus should be prevented.
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Affiliation(s)
- D Lastra González
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Prague - Suchdol, Czech Republic
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Bozzuto C, Schmidt BR, Canessa S. Active responses to outbreaks of infectious wildlife diseases: objectives, strategies and constraints determine feasibility and success. Proc Biol Sci 2020; 287:20202475. [PMID: 33234080 DOI: 10.1098/rspb.2020.2475] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Emerging wildlife diseases are taking a heavy toll on animal and plant species worldwide. Mitigation, particularly in the initial epidemic phase, is hindered by uncertainty about the epidemiology and management of emerging diseases, but also by vague or poorly defined objectives. Here, we use a quantitative analysis to assess how the decision context of mitigation objectives, available strategies and practical constraints influences the decision of whether and how to respond to epidemics in wildlife. To illustrate our approach, we parametrized the model for European fire salamanders affected by Batrachochytrium salamandrivorans, and explored different combinations of conservation, containment and budgetary objectives. We found that in approximately half of those scenarios, host removal strategies perform equal to or worse than no management at all during a local outbreak, particularly where removal cannot exclusively target infected individuals. Moreover, the window for intervention shrinks rapidly if an outbreak is detected late or if a response is delayed. Clearly defining the decision context is, therefore, vital to plan meaningful responses to novel outbreaks. Explicitly stating objectives, strategies and constraints, if possible before an outbreak occurs, avoids wasting precious resources and creating false expectations about what can and cannot be achieved during the epidemic phase.
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Affiliation(s)
- Claudio Bozzuto
- Wildlife Analysis GmbH, Oetlisbergstrasse 38, 8053 Zurich, Switzerland
| | - Benedikt R Schmidt
- Institut für Evolutionsbiologie und Umweltwissenschaften, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.,info fauna karch, UniMail, Bâtiment G, Bellevaux 51, 2000 Neuchâtel, Switzerland
| | - Stefano Canessa
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Instant killing of pathogenic chytrid fungi by disposable nitrile gloves prevents disease transmission between amphibians. PLoS One 2020; 15:e0241048. [PMID: 33119670 PMCID: PMC7595420 DOI: 10.1371/journal.pone.0241048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/07/2020] [Indexed: 12/03/2022] Open
Abstract
To prevent transmission of the pathogenic chytrid fungi Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), hygiene protocols prescribe the single use of disposable gloves for handling amphibians. We discovered that rinse water from nitrile gloves instantly kills 99% of Bd and Bsal zoospores. Transmission experiments using midwife toads (Alytes obstetricans) and Bd, and Alpine newts (Ichthyosaura alpestris) and Bsal, show that the use of the same pair of gloves for 2 subsequent individuals does not result in significant transmission of any chytrid fungus. In contrast, handling infected amphibians bare-handed caused transmission of Bsal in 4 out of 10 replicates, but did not result in transmission of Bd. Based on the manufacturer’s information, high resolution mass spectrometry (HRMS) and colorimetric tests, calcium lactate and calcium nitrate were identified as compounds with antifungal activity against both Bd and Bsal. These findings corroborate the importance of wearing gloves as an important sanitary measure in amphibian disease prevention. If the highly recommended single use of gloves is not possible, handling multiple post-metamorphic amphibians with the same pair of nitrile gloves should still be preferred above bare-handed manipulation.
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Presence of low virulence chytrid fungi could protect European amphibians from more deadly strains. Nat Commun 2020; 11:5393. [PMID: 33106491 PMCID: PMC7589487 DOI: 10.1038/s41467-020-19241-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 10/05/2020] [Indexed: 11/14/2022] Open
Abstract
Wildlife diseases are contributing to the current Earth’s sixth mass extinction; one disease, chytridiomycosis, has caused mass amphibian die-offs. While global spread of a hypervirulent lineage of the fungus Batrachochytrium dendrobatidis (BdGPL) causes unprecedented loss of vertebrate diversity by decimating amphibian populations, its impact on amphibian communities is highly variable across regions. Here, we combine field data with in vitro and in vivo trials that demonstrate the presence of a markedly diverse variety of low virulence isolates of BdGPL in northern European amphibian communities. Pre-exposure to some of these low virulence isolates protects against disease following subsequent exposure to highly virulent BdGPL in midwife toads (Alytes obstetricans) and alters infection dynamics of its sister species B. salamandrivorans in newts (Triturus marmoratus), but not in salamanders (Salamandra salamandra). The key role of pathogen virulence in the complex host-pathogen-environment interaction supports efforts to limit pathogen pollution in a globalized world. The pathogen Batrachochytrium dendrobatidis (BD) associated with widespread amphibian declines is present in Europe but has not consistently caused disease-induced declines in that region. Here, the authors suggest that an endemic strain of BD with low virulence may protect the hosts upon co-infection with more virulent strains.
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67
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Rodriguez KM, Voyles J. The amphibian complement system and chytridiomycosis. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 333:706-719. [PMID: 33052039 PMCID: PMC7821119 DOI: 10.1002/jez.2419] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/26/2020] [Accepted: 09/24/2020] [Indexed: 12/26/2022]
Abstract
Understanding host immune function and ecoimmunology is increasingly important at a time when emerging infectious diseases (EIDs) threaten wildlife. One EID that has emerged and spread widely in recent years is chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), which is implicated unprecedented amphibian declines around the world. The impacts of Bd have been severe for many amphibian species, but some populations have exhibited signs of persistence, and even recovery, in some regions. Many mechanisms may underpin this pattern and amphibian immune responses are likely one key component. Although we have made great strides in understanding amphibian immunity, the complement system remains poorly understood. The complement system is a nonspecific, innate immune defense that is known to enhance other immune responses. Complement activation can occur by three different biochemical pathways and result in protective mechanisms, such as inflammation, opsonization, and pathogen lysis, thereby providing protection to the host. We currently lack an understanding of complement pathway activation for chytridiomycosis, but several studies have suggested that it may be a key part of an early and robust immune response that confers host resistance. Here, we review the available research on the complement system in general as well as amphibian complement responses to Bd infection. Additionally, we propose future research directions that will increase our understanding of the amphibian complement system and other immune responses to Bd. Finally, we suggest how a deeper understanding of amphibian immunity could enhance the conservation and management of amphibian species that are threatened by chytridiomycosis.
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Affiliation(s)
| | - Jamie Voyles
- Department of Biology, University of Nevada-Reno, Reno, Nevada, USA
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Beukema W, Pasmans F, Van Praet S, Ferri-Yáñez F, Kelly M, Laking AE, Erens J, Speybroeck J, Verheyen K, Lens L, Martel A. Microclimate limits thermal behaviour favourable to disease control in a nocturnal amphibian. Ecol Lett 2020; 24:27-37. [PMID: 33022129 DOI: 10.1111/ele.13616] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/15/2020] [Accepted: 09/07/2020] [Indexed: 11/28/2022]
Abstract
While epizootics increasingly affect wildlife, it remains poorly understood how the environment shapes most host-pathogen systems. Here, we employ a three-step framework to study microclimate influence on ectotherm host thermal behaviour, focusing on amphibian chytridiomycosis in fire salamanders (Salamandra salamandra) infected with the fungal pathogen Batrachochytrium salamandrivorans (Bsal). Laboratory trials reveal that innate variation in thermal preference, rather than behavioural fever, can inhibit infection and facilitate salamander recovery under humidity-saturated conditions. Yet, a 3-year field study and a mesocosm experiment close to the invasive Bsal range show that microclimate constraints suppress host thermal behaviour favourable to disease control. A final mechanistic model, that estimates range-wide, year-round host body temperature relative to microclimate, suggests that these constraints are rule rather than exception. Our results demonstrate how innate host defences against epizootics may remain constrained in the wild, which predisposes to range-wide disease outbreaks and population declines.
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Affiliation(s)
- Wouter Beukema
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Sarah Van Praet
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Francisco Ferri-Yáñez
- Department of Community Ecology, Helmholtz Centre for Environmental Research (UFZ), Theodor-Lieser-Strasse 4, Halle, 06120, Germany
| | - Moira Kelly
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Alexandra E Laking
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Jesse Erens
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Jeroen Speybroeck
- Research Institute for Nature and Forest - INBO, Havenlaan 88 bus 73, Brussels, 1000, Belgium
| | - Kris Verheyen
- Forest & Nature Lab, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, Gontrode, 9090, Belgium
| | - Luc Lens
- Terrestrial Ecology Unit, Ghent University, K. L, Ledeganckstraat 35, Ghent, 9000, Belgium
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
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Li Z, Martel A, Bogaerts S, Göçmen B, Pafilis P, Lymberakis P, Woeltjes T, Veith M, Pasmans F. Landscape Connectivity Limits the Predicted Impact of Fungal Pathogen Invasion. J Fungi (Basel) 2020; 6:E205. [PMID: 33022972 PMCID: PMC7712934 DOI: 10.3390/jof6040205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 12/11/2022] Open
Abstract
Infectious diseases are major drivers of biodiversity loss. The risk of fungal diseases to the survival of threatened animals in nature is determined by a complex interplay between host, pathogen and environment. We here predict the risk of invasion of populations of threatened Mediterranean salamanders of the genus Lyciasalamandra by the pathogenic chytrid fungus Batrachochytrium salamandrivorans by combining field sampling and lab trials. In 494 samples across all seven species of Lyciasalamandra, B. salamandrivorans was found to be absent. Single exposure to a low (1000) number of fungal zoospores resulted in fast buildup of lethal infections in three L. helverseni. Thermal preference of the salamanders was well within the thermal envelope of the pathogen and body temperatures never exceeded the fungus' thermal critical maximum, limiting the salamanders' defense opportunities. The relatively low thermal host preference largely invalidates macroclimatic based habitat suitability predictions and, combined with current pathogen absence and high host densities, suggests a high probability of local salamander population declines upon invasion by B. salamandrivorans. However, the unfavorable landscape that shaped intraspecific host genetic diversity, lack of known alternative hosts and rapid host mortality after infection present barriers to further, natural pathogen dispersal between populations and thus species extinction. The risk of anthropogenic spread stresses the importance of biosecurity in amphibian habitats.
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Affiliation(s)
- Zhimin Li
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B9820 Merelbeke, Belgium; (Z.L.); (A.M.)
| | - An Martel
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B9820 Merelbeke, Belgium; (Z.L.); (A.M.)
| | | | - Bayram Göçmen
- Faculty of Science, Department of Biology, Zoology Section, Ege University, TR-35100 İzmir, Turkey
| | - Panayiotis Pafilis
- Department of Zoology and Marine Biology, School of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Ilissia, 15784 Athens, Greece;
| | - Petros Lymberakis
- Natural History Museum of Crete, School of Sciences and Engineering, University of Crete, Knossos Ave., 1409 Irakleio, Greece;
| | | | - Michael Veith
- Department of Biogeography, Trier University, Universitätsring 15, D-54296 Trier, Germany;
| | - Frank Pasmans
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B9820 Merelbeke, Belgium; (Z.L.); (A.M.)
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Brannelly LA, Wetzel DP, Ohmer MEB, Zimmerman L, Saenz V, Richards-Zawacki CL. Evaluating environmental DNA as a tool for detecting an amphibian pathogen using an optimized extraction method. Oecologia 2020; 194:267-281. [PMID: 32880026 DOI: 10.1007/s00442-020-04743-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 08/26/2020] [Indexed: 12/29/2022]
Abstract
Environmental DNA (eDNA) detection is a valuable conservation tool that can be used to identify and monitor imperiled or invasive species and wildlife pathogens. Batrachochytrium pathogens are of global conservation concern because they are a leading cause of amphibian decline. While eDNA techniques have been used to detect Batrachochytrium DNA in the environment, a systematic comparison of extraction methods across environmental samples is lacking. In this study, we first compared eDNA extraction methods and found that a soil extraction kit (Qiagen PowerSoil) was the most effective for detecting Batrachochytrium dendrobatidis in water samples. The PowerSoil extraction had a minimum detection level of 100 zoospores and had a two- to four-fold higher detection probability than other commonly used extraction methods (e.g., QIAamp extraction, DNeasy+Qiashredder extraction method, respectively). Next, we used this extraction method on field-collected water and sediment samples and were able to detect pathogen DNA in both. While field-collected water filters were equivalent to amphibian skin swab samples in detecting the presence of pathogen DNA, the seasonal patterns in pathogen quantity were different between skin swabs and water samples. Detection rate was lowest in sediment samples. We also found that detection probability increases with the volume of water filtered. Our results indicate that water filter eDNA samples can be accurate in detecting pathogen presence at the habitat scale but their utility for quantifying pathogen loads in the environment appears limited. We suggest that eDNA techniques be used for early warning detection to guide animal sampling efforts.
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Affiliation(s)
- Laura A Brannelly
- Department of Biological Science, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
- Melbourne Veterinary School, Faculty of Agricultural and Veterinary Sciences, University of Melbourne, Werribee, VIC, Australia.
| | - Daniel P Wetzel
- Department of Biological Science, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michel E B Ohmer
- Department of Biological Science, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Lydia Zimmerman
- Department of Biological Science, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Veronica Saenz
- Department of Biological Science, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Corinne L Richards-Zawacki
- Department of Biological Science, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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71
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Kumar R, Malagon DA, Carter ED, Miller DL, Bohanon ML, Cusaac JPW, Peterson AC, Gray MJ. Experimental methodologies can affect pathogenicity of Batrachochytrium salamandrivorans infections. PLoS One 2020; 15:e0235370. [PMID: 32915779 PMCID: PMC7485798 DOI: 10.1371/journal.pone.0235370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/24/2020] [Indexed: 12/30/2022] Open
Abstract
Controlled experiments are one approach to understanding the pathogenicity of etiologic agents to susceptible hosts. The recently discovered fungal pathogen, Batrachochytrium salamandrivorans (Bsal), has resulted in a surge of experimental investigations because of its potential to impact global salamander biodiversity. However, variation in experimental methodologies could thwart knowledge advancement by introducing confounding factors that make comparisons difficult among studies. Thus, our objective was to evaluate if variation in experimental methods changed inferences made on the pathogenicity of Bsal. We tested whether passage duration of Bsal culture, exposure method of the host to Bsal (water bath vs. skin inoculation), Bsal culturing method (liquid vs. plated), host husbandry conditions (aquatic vs. terrestrial), and skin swabbing frequency influenced diseased-induced mortality in a susceptible host species, the eastern newt (Notophthalmus viridescens). We found that disease-induced mortality was faster for eastern newts when exposed to a low passage isolate, when newts were housed in terrestrial environments, and if exposure to zoospores occurred via water bath. We did not detect differences in disease-induced mortality between culturing methods or swabbing frequencies. Our results illustrate the need to standardize methods among Bsal experiments. We provide suggestions for future Bsal experiments in the context of hypothesis testing and discuss the ecological implications of our results.
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Affiliation(s)
- Rajeev Kumar
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
| | - Daniel A. Malagon
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
| | - Edward Davis Carter
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
| | - Debra L. Miller
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Markese L. Bohanon
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
| | - Joseph Patrick W. Cusaac
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
| | - Anna C. Peterson
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
| | - Matthew J. Gray
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, Tennessee, United States of America
- * E-mail:
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72
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De Troyer N, Eurie Forio MA, Roels K, De Meester L, Lemmens P, Declerck SA, Martens K, Goethals P. Key management rules for agricultural alpine newt breeding ponds based on habitat suitability models. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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73
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Burrowes PA, James TY, Jenkinson TS, De la Riva I. Genetic analysis of post-epizootic amphibian chytrid strains in Bolivia: Adding a piece to the puzzle. Transbound Emerg Dis 2020; 67:2163-2171. [PMID: 32277592 DOI: 10.1111/tbed.13568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/11/2020] [Accepted: 03/14/2020] [Indexed: 12/26/2022]
Abstract
The evolutionary history and dispersal pattern of Batrachochytrium dendrobatidis (Bd), an emergent fungal pathogen responsible for the decline and extinctions of many species of amphibians worldwide, is still not well understood. In South America, the tropical Andes are known as an important site for amphibian diversification, but also for being a place where hosts are at greater risk of chytridiomycosis. In an attempt to understand the history and the geographic pattern of Bd-associated amphibian declines in Bolivia, we isolated Bd from hosts at two locations that differ in their chronology of Bd prevalence and host survival outcome, the cloud forests of the Amazonian slopes of the Andes and Lake Titicaca in the altiplano. We genotyped Bd from both locations and sequenced the genome from the cloud forest isolate and then compared them to reference sequences of other Bd strains across the world. We found that the Bolivian chytrid isolates were nearly genotypically identical and that they belong to the global panzootic lineage (Bd-GPL). The Bolivian Bd strain grouped with other tropical New World strains but was closest to those from the Brazilian Atlantic Forest. Our results extend the presence of Bd-GPL to the central Andes in South America and report this hypervirulent strain at Lago Titicaca, where Bd has been detected since 1863, without evidence of amphibian declines. These findings suggest a more complex evolutionary history for this pathogen in Bolivia and may point to the existence of an old lineage of Bd that has since been extirpated following the arrival of the panzootic Bd-GPL or that the timing of Bd-GPL emergence is earlier than generally acknowledged.
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Affiliation(s)
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Thomas S Jenkinson
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
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74
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Batrachochytrium salamandrivorans (Bsal) not detected in an intensive survey of wild North American amphibians. Sci Rep 2020; 10:13012. [PMID: 32747670 PMCID: PMC7400573 DOI: 10.1038/s41598-020-69486-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 05/22/2020] [Indexed: 11/22/2022] Open
Abstract
The salamander chytrid fungus (Batrachochytrium salamandrivorans [Bsal]) is causing massive mortality of salamanders in Europe. The potential for spread via international trade into North America and the high diversity of salamanders has catalyzed concern about Bsal in the U.S. Surveillance programs for invading pathogens must initially meet challenges that include low rates of occurrence on the landscape, low prevalence at a site, and imperfect detection of the diagnostic tests. We implemented a large-scale survey to determine if Bsal was present in North America designed to target taxa and localities where Bsal was determined highest risk to be present based on species susceptibility and geography. Our analysis included a Bayesian model to estimate the probability of occurrence of Bsal given our prior knowledge of the occurrence and prevalence of the pathogen. We failed to detect Bsal in any of 11,189 samples from 594 sites in 223 counties within 35 U.S. states and one site in Mexico. Our modeling indicates that Bsal is highly unlikely to occur within wild amphibians in the U.S. and suggests that the best proactive response is to continue mitigation efforts against the introduction and establishment of the disease and to develop plans to reduce impacts should Bsal establish.
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75
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Tehel A, Streicher T, Tragust S, Paxton RJ. Experimental infection of bumblebees with honeybee-associated viruses: no direct fitness costs but potential future threats to novel wild bee hosts. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200480. [PMID: 32874644 PMCID: PMC7428241 DOI: 10.1098/rsos.200480] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/10/2020] [Indexed: 05/05/2023]
Abstract
Pathogen spillover represents an important cause of biodiversity decline. For wild bee species such as bumblebees, many of which are in decline, correlational data point towards viral spillover from managed honeybees as a potential cause. Yet, impacts of these viruses on wild bees are rarely evaluated. Here, in a series of highly controlled laboratory infection assays with well-characterized viral inocula, we show that three viral types isolated from honeybees (deformed wing virus genotype A, deformed wing virus genotype B and black queen cell virus) readily replicate within hosts of the bumblebee Bombus terrestris. Impacts of these honeybee-derived viruses - either injected or fed - on the mortality of B. terrestris workers were, however, negligible and probably dependent on host condition. Our results highlight the potential threat of viral spillover from honeybees to novel wild bee species, though they also underscore the importance of additional studies on this and other wild bee species under field-realistic conditions to evaluate whether pathogen spillover has a negative impact on wild bee individuals and population fitness.
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Affiliation(s)
- Anja Tehel
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Tabea Streicher
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Simon Tragust
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
| | - Robert J. Paxton
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
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76
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Brunner JL. Pooled samples and eDNA-based detection can facilitate the "clean trade" of aquatic animals. Sci Rep 2020; 10:10280. [PMID: 32581260 PMCID: PMC7314758 DOI: 10.1038/s41598-020-66280-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/18/2020] [Indexed: 12/17/2022] Open
Abstract
The regional and international trade of live animals facilitates the movement, spillover, and emergence of zoonotic and epizootic pathogens around the world. Detecting pathogens in trade is critical for preventing their continued movement and introduction, but screening a sufficient fraction to ensure rare infections are detected is simply infeasible for many taxa and settings because of the vast numbers of animals involved—hundreds of millions of live animals are imported into the U.S.A. alone every year. Batch processing pools of individual samples or using environmental DNA (eDNA)—the genetic material shed into an organism’s environment—collected from whole consignments of animals may substantially reduce the time and cost associated with pathogen surveillance. Both approaches, however, lack a framework with which to determine sampling requirements and interpret results. Here I present formulae for pooled individual samples (e.g,. swabs) and eDNA samples collected from finite populations and discuss key assumptions and considerations for their use with a focus on detecting Batrachochytrium salamandrivorans, an emerging pathogen that threatens global salamander diversity. While empirical validation is key, these formulae illustrate the potential for eDNA-based detection in particular to reduce sample sizes and help bring clean trade into reach for a greater number of taxa, places, and contexts.
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Affiliation(s)
- Jesse L Brunner
- Washington State University, School of Biological Sciences, Pullman, WA, 99164, USA.
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77
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Rollins-Smith LA. Global Amphibian Declines, Disease, and the Ongoing Battle between Batrachochytrium Fungi and the Immune System. HERPETOLOGICA 2020. [DOI: 10.1655/0018-0831-76.2.178] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Louise A. Rollins-Smith
- Departments of Pathology, Microbiology and Immunology and Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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Zimkus BM, Baláž V, Belasen AM, Bell RC, Channing A, Doumbia J, Fokam EB, Gonwouo LN, Greenbaum E, Gvoždík V, Hirschfeld M, Jackson K, James TY, Kusamba C, Larson JG, Mavoungou LB, Rödel MO, Zassi-Boulou AG, Penner J. Chytrid Pathogen (Batrachochytrium dendrobatidis) in African Amphibians: A Continental Analysis of Occurrences and Modeling of Its Potential Distribution. HERPETOLOGICA 2020. [DOI: 10.1655/0018-0831-76.2.201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Breda M. Zimkus
- Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA
| | - Vojtech Baláž
- University of Veterinary and Pharmaceutical Sciences Brno, Faculty of Veterinary Hygiene and Ecology, Department of Biology and Wildlife Diseases, 612 42 Brno, Czech Republic
| | - Anat M. Belasen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Rayna C. Bell
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Alan Channing
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, 2520, South Africa
| | - Joseph Doumbia
- ONG EnviSud Guinée Commune Ratoma 030BP:558 4720 Conakry, Guinée
| | - Eric B. Fokam
- Department of Zoology and Animal Physiology, University of Buea, 00237, Cameroon
| | - LeGrand N. Gonwouo
- Laboratory of Zoology, Faculty of Sciences, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
| | - Eli Greenbaum
- Department of Biological Sciences, University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968, USA
| | - Václav Gvoždík
- Institute of Vertebrate Biology of the Czech Academy of Sciences, 603 65 Brno, Czech Republic
| | - Mareike Hirschfeld
- Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, 10115 Berlin, Germany
| | - Kate Jackson
- Department of Biology, Whitman College, 345 Boyer Avenue, Walla Walla, WA 99362, USA
| | - Timothy Y. James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chifundera Kusamba
- Centre de Recherche en Sciences Naturelles, Département de Biologie, Lwiro, The Democratic Republic of the Congo
| | - Joanna G. Larson
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lise-Bethy Mavoungou
- Institut National de Recherche en Sciences Exactes et Naturelles (IRSEN), Cité Scientifique (Ex-ORSTOM), 2400, République du Congo
| | - Mark-Oliver Rödel
- Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, 10115 Berlin, Germany
| | - Ange-Ghislain Zassi-Boulou
- Institut National de Recherche en Sciences Exactes et Naturelles (IRSEN), Cité Scientifique (Ex-ORSTOM), 2400, République du Congo
| | - Johannes Penner
- Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, 10115 Berlin, Germany
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Robinson KA, Pereira KE, Bletz MC, Carter ED, Gray MJ, Piovia-Scott J, Romansic JM, Woodhams DC, Fritz-Laylin L. Isolation and maintenance of Batrachochytrium salamandrivorans cultures. DISEASES OF AQUATIC ORGANISMS 2020; 140:1-11. [PMID: 32618283 DOI: 10.3354/dao03488] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Discovered in 2013, the chytrid fungus Batrachochytrium salamandrivorans (Bsal) is an emerging amphibian pathogen that causes ulcerative skin lesions and multifocal erosion. A closely related pathogen, B. dendrobatidis (Bd), has devastated amphibian populations worldwide, suggesting that Bsal poses a significant threat to global salamander biodiversity. To expedite research into this emerging threat, we seek to standardize protocols across the field so that results of laboratory studies are reproducible and comparable. We have collated data and experience from multiple labs to standardize culturing practices of Bsal. Here we outline common culture practices including a medium for standardized Bsal growth, standard culturing protocols, and a method for isolating Bsal from infected tissue.
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Affiliation(s)
- Kristyn A Robinson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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80
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Malagon DA, Melara LA, Prosper OF, Lenhart S, Carter ED, Fordyce JA, Peterson AC, Miller DL, Gray MJ. Host density and habitat structure influence host contact rates and Batrachochytrium salamandrivorans transmission. Sci Rep 2020; 10:5584. [PMID: 32221329 PMCID: PMC7101388 DOI: 10.1038/s41598-020-62351-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 03/11/2020] [Indexed: 12/22/2022] Open
Abstract
Batrachochytrium salamandrivorans (Bsal) is an emerging invasive pathogen that is highly pathogenic to salamander species. Modeling infection dynamics in this system can facilitate proactive efforts to mitigate this pathogen's impact on North American species. Given its widespread distribution and high abundance, the eastern newt (Notophthalmus viridescens) has the potential to significantly influence Bsal epidemiology. We designed experiments to 1) estimate contact rates given different host densities and habitat structure and 2) estimate the probability of transmission from infected to susceptible individuals. Using parameter estimates from data generated during these experiments, we modeled infection and disease outcomes for a population of newts using a system of differential equations. We found that host contact rates were density-dependent, and that adding habitat structure reduced contacts. The probability of Bsal transmission given contact between newts was very high (>90%) even at early stages of infection. Our simulations show rapid transmission of Bsal among individuals following pathogen introduction, with infection prevalence exceeding 90% within one month and >80% mortality of newts in three months. Estimates of basic reproductive rate (R0) of Bsal for eastern newts were 1.9 and 3.2 for complex and simple habitats, respectively. Although reducing host density and increasing habitat complexity might decrease transmission, these management strategies may be ineffective at stopping Bsal invasion in eastern newt populations due to this species’ hyper-susceptibility.
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Affiliation(s)
- Daniel A Malagon
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - Luis A Melara
- Department of Mathematics, Shippensburg University, Shippensburg, PA, 17257, USA
| | - Olivia F Prosper
- Department of Mathematics, University of Kentucky, Lexington, KY, 40506, USA.,Department of Mathematics, University of Tennessee, Knoxville, TN, 37996, USA
| | - Suzanne Lenhart
- Department of Mathematics, University of Tennessee, Knoxville, TN, 37996, USA
| | - Edward Davis Carter
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - J A Fordyce
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Anna C Peterson
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - Debra L Miller
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA.,Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, 37996, USA
| | - Matthew J Gray
- Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA.
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81
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Abstract
Discovering that chytrid fungi cause chytridiomycosis in amphibians represented a paradigm shift in our understanding of how emerging infectious diseases contribute to global patterns of biodiversity loss. In this Review we describe how the use of multidisciplinary biological approaches has been essential to pinpointing the origins of amphibian-parasitizing chytrid fungi, including Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, as well as to timing their emergence, tracking their cycles of expansion and identifying the core mechanisms that underpin their pathogenicity. We discuss the development of the experimental methods and bioinformatics toolkits that have provided a fuller understanding of batrachochytrid biology and informed policy and control measures.
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82
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Sauer EL, Cohen JM, Lajeunesse MJ, McMahon TA, Civitello DJ, Knutie SA, Nguyen K, Roznik EA, Sears BF, Bessler S, Delius BK, Halstead N, Ortega N, Venesky MD, Young S, Rohr JR. A meta-analysis reveals temperature, dose, life stage, and taxonomy influence host susceptibility to a fungal parasite. Ecology 2020; 101:e02979. [PMID: 31960949 DOI: 10.1002/ecy.2979] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 10/25/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022]
Abstract
Complex ecological relationships, such as host-parasite interactions, are often modeled with laboratory experiments. However, some experimental laboratory conditions, such as temperature or infection dose, are regularly chosen based on convenience or convention, and it is unclear how these decisions systematically affect experimental outcomes. Here, we conducted a meta-analysis of 58 laboratory studies that exposed amphibians to the pathogenic fungus Batrachochytrium dendrobatidis (Bd) to understand better how laboratory temperature, host life stage, infection dose, and host species affect host mortality. We found that host mortality was driven by thermal mismatches: hosts native to cooler environments experienced greater Bd-induced mortality at relatively warm experimental temperatures and vice versa. We also found that Bd dose positively predicted Bd-induced host mortality and that the superfamilies Bufonoidea and Hyloidea were especially susceptible to Bd. Finally, the effect of Bd on host mortality varied across host life stages, with larval amphibians experiencing lower risk of Bd-induced mortality than adults or metamorphs. Metamorphs were especially susceptible and experienced mortality when inoculated with much smaller Bd doses than the average dose used by researchers. Our results suggest that when designing experiments on species interactions, researchers should carefully consider the experimental temperature, inoculum dose, and life stage, and taxonomy of the host species.
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Affiliation(s)
- Erin L Sauer
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA.,Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Dr., Madison, 53706, Wisconsin, USA
| | - Jeremy M Cohen
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA.,Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Dr., Madison, 53706, Wisconsin, USA
| | - Marc J Lajeunesse
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Taegan A McMahon
- Department of Biology, University of Tampa, 401 W. Kennedy Blvd., Tampa, 33606, Florida, USA
| | - David J Civitello
- Department of Biology, Emory University, 201 Dowman Dr., Atlanta, 30322, Georgia, USA
| | - Sarah A Knutie
- Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road, Storrs, 06269, Connecticut, USA
| | - Karena Nguyen
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Elizabeth A Roznik
- Department of Research and Conservation, Memphis Zoo, 2000 Prentiss Place, Memphis, 38112, Tennessee, USA
| | | | - Scott Bessler
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Bryan K Delius
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Neal Halstead
- Wildlands Conservation, 15310 Amberly Dr., Suite 250, Tampa, 33647, Florida, USA
| | - Nicole Ortega
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Matthew D Venesky
- Department of Biology, Allegheny College, 520 N Main St., Meadville, 16335, Pennsylvania, USA
| | - Suzanne Young
- Environmental Engineering Institute, Ecole polytechnique fédérale de Lausanne (EPFL), Route Cantonale, 1015, Lausanne, Switzerland
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA.,Department of Biological Science, University of Notre Dame, 100 Galvin Life Science Center, Notre Dame, 46656, Indiana, USA
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83
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Martel A, Vila‐Escale M, Fernández‐Giberteau D, Martinez‐Silvestre A, Canessa S, Van Praet S, Pannon P, Chiers K, Ferran A, Kelly M, Picart M, Piulats D, Li Z, Pagone V, Pérez‐Sorribes L, Molina C, Tarragó‐Guarro A, Velarde‐Nieto R, Carbonell F, Obon E, Martínez‐Martínez D, Guinart D, Casanovas R, Carranza S, Pasmans F. Integral chain management of wildlife diseases. Conserv Lett 2020. [DOI: 10.1111/conl.12707] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- An Martel
- Wildlife Health GhentDepartment of PathologyBacteriology and Avian Diseases, Faculty of Veterinary MedicineGhent University Merelbeke Belgium
| | - Mireia Vila‐Escale
- Oficina Tècnica de Parcs Naturals. Diputació de Barcelona Barcelona Spain
| | - Daniel Fernández‐Giberteau
- Grup de Recerca de l'Escola de la Natura de Parets del Vallès – Ajuntament de Parets del Vallès Parets del Vallès Spain
| | | | - Stefano Canessa
- Wildlife Health GhentDepartment of PathologyBacteriology and Avian Diseases, Faculty of Veterinary MedicineGhent University Merelbeke Belgium
| | - Sarah Van Praet
- Wildlife Health GhentDepartment of PathologyBacteriology and Avian Diseases, Faculty of Veterinary MedicineGhent University Merelbeke Belgium
| | - Pep Pannon
- Oficina Tècnica de Parcs Naturals. Diputació de Barcelona Barcelona Spain
| | - Koen Chiers
- Wildlife Health GhentDepartment of PathologyBacteriology and Avian Diseases, Faculty of Veterinary MedicineGhent University Merelbeke Belgium
| | - Albert Ferran
- Oficina Tècnica de Parcs Naturals. Diputació de Barcelona Barcelona Spain
| | - Moira Kelly
- Wildlife Health GhentDepartment of PathologyBacteriology and Avian Diseases, Faculty of Veterinary MedicineGhent University Merelbeke Belgium
| | - Mariona Picart
- Oficina Tècnica de Parcs Naturals. Diputació de Barcelona Barcelona Spain
| | - Dolors Piulats
- Institute of Evolutionary Biology (CSIC‐UPF) Barcelona Spain
| | - Zhimin Li
- Wildlife Health GhentDepartment of PathologyBacteriology and Avian Diseases, Faculty of Veterinary MedicineGhent University Merelbeke Belgium
| | - Viviana Pagone
- Institute of Evolutionary Biology (CSIC‐UPF) Barcelona Spain
| | - Laia Pérez‐Sorribes
- Grup de Recerca de l'Escola de la Natura de Parets del Vallès – Ajuntament de Parets del Vallès Parets del Vallès Spain
| | - Carolina Molina
- Grup de Recerca de l'Escola de la Natura de Parets del Vallès – Ajuntament de Parets del Vallès Parets del Vallès Spain
| | - Aïda Tarragó‐Guarro
- Departament de Territori i SostenibilitatGeneralitat de Catalunya Barcelona Spain
| | - Roser Velarde‐Nieto
- Departament de Medicina i Cirurgia AnimalsFacultat de VeterinàriaUniversitat Autònoma de Barcelona Bellaterra Spain
| | - Francesc Carbonell
- Àrea de Gestió Ambiental Servei de Fauna i Flora (Centre de Fauna de Torreferrussa) Santa Perpètua de Mogoda Spain
| | - Elena Obon
- Àrea de Gestió Ambiental Servei de Fauna i Flora (Centre de Fauna de Torreferrussa) Santa Perpètua de Mogoda Spain
| | | | - Daniel Guinart
- Oficina Tècnica de Parcs Naturals. Diputació de Barcelona Barcelona Spain
| | - Ricard Casanovas
- Departament de Territori i SostenibilitatGeneralitat de Catalunya Barcelona Spain
| | | | - Frank Pasmans
- Wildlife Health GhentDepartment of PathologyBacteriology and Avian Diseases, Faculty of Veterinary MedicineGhent University Merelbeke Belgium
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84
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Barnhart KL, Bletz MC, LaBumbard BC, Tokash-Peters AG, Gabor CR, Woodhams DC. Batrachochytrium salamandrivorans ELICITS ACUTE STRESS RESPONSE IN SPOTTED SALAMANDERS BUT NOT INFECTION OR MORTALITY. Anim Conserv 2020; 23:533-546. [PMID: 33071596 DOI: 10.1111/acv.12565] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The emerging fungal pathogen Batrachochytrium salamandrivorans (Bsal) is a major threat to amphibian species worldwide with potential to infect many species if it invades salamander biodiversity hotspots in the Americas. Bsal can cause the disease chytridiomycosis, and it is important to assess the risk of Bsal-induced chytridiomycosis to species in North America. We evaluated the susceptibility to Bsal of the common and widespread spotted salamander, Ambystoma maculatum, across life history stages and monitored the effect of Bsal exposure on growth rate and response of the stress hormone, corticosterone. We conclude that spotted salamanders appear resistant to Bsal because they showed no indication of disease or infection, and experienced minor effects on growth upon exposure. While we focused on a single population for this study, results were consistent across conditions of exposure including high or repeated doses of Bsal, life-stage at exposure, environmental conditions including two temperatures and two substrates, and promoting pathogen infectivity by conditioning Bsal cultures with thyroid hormone. Exposure to high levels of Bsal elicited an acute but not chronic increase in corticosterone in spotted salamanders, and reduced growth. We hypothesize that the early acute increase in corticosterone facilitated mounting an immune response to the pathogen, perhaps through immunoredistribution to the skin, but further study is needed to determine immune responses to Bsal. These results will contribute to development of appropriate Bsal management plans to conserve species at risk of emerging disease.
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Affiliation(s)
- Kelly L Barnhart
- University of Massachusetts Boston, Department of Biology, 100 William T Morrissey Blvd, Boston, MA 02125
| | - Molly C Bletz
- University of Massachusetts Boston, Department of Biology, 100 William T Morrissey Blvd, Boston, MA 02125
| | - Brandon C LaBumbard
- University of Massachusetts Boston, Department of Biology, 100 William T Morrissey Blvd, Boston, MA 02125
| | - Amanda G Tokash-Peters
- University of Massachusetts Boston, Department of Biology, 100 William T Morrissey Blvd, Boston, MA 02125
| | - Caitlin R Gabor
- Texas State University, Department of Biology, 601 University Drive, San Marcos, TX 78666
| | - Douglas C Woodhams
- University of Massachusetts Boston, Department of Biology, 100 William T Morrissey Blvd, Boston, MA 02125
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85
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Ellison A, Zamudio K, Lips K, Muletz‐Wolz C. Temperature‐mediated shifts in salamander transcriptomic responses to the amphibian‐killing fungus. Mol Ecol 2020; 29:325-343. [DOI: 10.1111/mec.15327] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/04/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Amy Ellison
- School of Natural Sciences Bangor University Bangor UK
| | - Kelly Zamudio
- Department of Ecology & Evolutionary Biology Cornell University Ithaca NY USA
| | - Karen Lips
- Department of Biology University of Maryland College Park MD USA
| | - Carly Muletz‐Wolz
- Department of Biology University of Maryland College Park MD USA
- Center for Conservation Genomics Smithsonian Conservation Biology Institute National Zoological Park Washington DC USA
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86
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Lastra González D, Baláž V, Solský M, Thumsová B, Kolenda K, Najbar A, Najbar B, Kautman M, Chajma P, Balogová M, Vojar J. Recent Findings of Potentially Lethal Salamander Fungus Batrachochytrium salamandrivorans. Emerg Infect Dis 2019; 25:1416-1418. [PMID: 31211934 PMCID: PMC6590763 DOI: 10.3201/eid2507.181001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The distribution of the chytrid fungus Batrachochytrium salamandrivorans continues to expand in Europe. During 2014-2018, we collected 1,135 samples from salamanders and newts in 6 countries in Europe. We identified 5 cases of B. salamandrivorans in a wild population in Spain but none in central Europe or the Balkan Peninsula.
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87
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Global Catastrophic Threats from the Fungal Kingdom : Fungal Catastrophic Threats. Curr Top Microbiol Immunol 2019; 424:21-32. [PMID: 31119433 DOI: 10.1007/82_2019_161] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
The fungal kingdom poses major catastrophic threats to humanity but these are often unappreciated and minimized, in biological threat assessments. The causes for this blind spot are complex and include the remarkable natural resistance of humans to pathogenic fungi, the lack of contagiousness of human fungal diseases, and the indirectness of fungal threats, which are more likely to mediate their destructive effects on crops and ecosystems. A review of historical events reveals that the fungal kingdom includes major threats to humanity through their effects on human health, agriculture, and destruction of materiel. A major concern going forward is the likelihood that physiological adaptations by fungal species to global warming will bring new fungal threats. Fungal threats pose significant challenges specific to this group of organisms including the potential for intercontinental spread by air currents, capacity for rapid evolution, a paucity of effective drugs, the absence of vaccines, and increasing drug resistance. Preparedness against bio-catastrophic risks must include consideration of the threats posed by fungi, which in turn requires a greater investment in mycology-related research.
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88
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Bletz MC, Bunk B, Spröer C, Biwer P, Reiter S, Rabemananjara FCE, Schulz S, Overmann J, Vences M. Amphibian skin-associated Pigmentiphaga: Genome sequence and occurrence across geography and hosts. PLoS One 2019; 14:e0223747. [PMID: 31603945 PMCID: PMC6788695 DOI: 10.1371/journal.pone.0223747] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/29/2019] [Indexed: 11/19/2022] Open
Abstract
The bacterial communities colonizing amphibian skin have been intensively studied due to their interactions with pathogenic chytrid fungi that are causing drastic amphibian population declines. Bacteria of the family Alcaligenaceae, and more specifically of the genus Pigmentiphaga, have been found to be associated specifically to arboreal frogs. Here we analyze their occurrence in a previously assembled global skin microbiome dataset from 205 amphibian species. Pigmentiphaga made up about 5% of the total number of reads in this global dataset. They were mostly found in unrelated arboreal frogs from Madagascar (Mantellidae and Hyperoliidae), but also occurred at low abundances on Neotropical frogs. Based on their 16S sequences, most of the sequences belong to a clade within Pigmentiphaga not assignable to any type strains of the five described species of the genus. One isolate from Madagascar clustered with Pigmentiphaga aceris (>99% sequence similarity on 16S rRNA gene level). Here, we report the full genome sequence of this bacterium which, based on 16S sequences of >97% similarity, has previously been found on human skin, floral nectar, tree sap, stream sediment and soil. Its genome consists of a single circular chromosome with 6,165,255 bp, 5,300 predicted coding sequences, 57 tRNA genes, and three rRNA operons. In comparison with other known Pigmentiphaga genomes it encodes a higher number of genes associated with environmental information processing and cellular processes. Furthermore, it has a biosynthetic gene cluster for a nonribosomal peptide syntethase, and bacteriocin biosynthetic genes can be found, but clusters for β-lactones present in other comparative Pigmentiphaga genomes are lacking.
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Affiliation(s)
- Molly C. Bletz
- Department of Biology, University of Massachusetts Boston, Boston, MA, United States of America
- Zoological Institute, Technische Universitt Braunschweig, Braunschweig, Germany
- * E-mail:
| | - Boyke Bunk
- DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Peter Biwer
- Institute of Organic Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Silke Reiter
- Institute for Insect Biotechnology, Justus Liebig University Giessen, Giessen, Germany
| | | | - Stefan Schulz
- Institute of Organic Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Jörg Overmann
- DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
- Microbiology Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Miguel Vences
- Zoological Institute, Technische Universitt Braunschweig, Braunschweig, Germany
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89
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Canessa S, Bozzuto C, Pasmans F, Martel A. Quantifying the burden of managing wildlife diseases in multiple host species. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2019; 33:1131-1140. [PMID: 30868671 DOI: 10.1111/cobi.13313] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/20/2018] [Accepted: 01/24/2019] [Indexed: 06/09/2023]
Abstract
Mitigation of infectious wildlife diseases is especially challenging where pathogens affect communities of multiple host species. Although most ecological studies recognize the challenge posed by multiple-species pathogens, the implications for management are typically assessed only qualitatively. Translating the intuitive understanding that multiple host species are important into practice requires a quantitative assessment of whether and how secondary host species should also be targeted by management and the effort this will require. Using a multiple-species compartmental model, we determined analytically whether and how intensively secondary host species should be managed to prevent outbreaks in focal hosts based on the reproduction number of individual host species and between-species transmission rates. We applied the model to the invasive pathogenic fungus Batrachochytrium salamandrivorans in a 2-host system in northern Europe. Avoiding a disease outbreak in the focal host (fire salamanders [Salamandra salamandra]) was impossible unless management also heavily targeted the secondary host (alpine newts [Ichthyosaura alpestris]). Preventing an outbreak in the community required targeted removal of at least 80% of each species. This proportion increased to 90% in the presence of an environmental reservoir of B. salamandrivorans and when the proportion of individuals removed could not be adjusted for different host species (e.g., when using traps that are not species specific). We recommend the focus of disease-mitigation plans should shift from focal species to the community level and calculate explicitly the management efforts required on secondary host species to move beyond the simple intuitive understanding that multiple host species may all influence the system. Failure to do so may lead to underestimating the magnitude of the effort required and ultimately to suboptimal or futile management attempts.
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Affiliation(s)
- Stefano Canessa
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Claudio Bozzuto
- Wildlife Analysis GmbH, Oetlisbergstrasse 38, 8053, Zurich, Switzerland
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
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90
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Carter ED, Miller DL, Peterson AC, Sutton WB, Cusaac JPW, Spatz JA, Rollins‐Smith L, Reinert L, Bohanon M, Williams LA, Upchurch A, Gray MJ. Conservation risk of
Batrachochytrium salamandrivorans
to endemic lungless salamanders. Conserv Lett 2019. [DOI: 10.1111/conl.12675] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Edward Davis Carter
- Center for Wildlife Health, Department of ForestryWildlife and FisheriesUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
| | - Debra L. Miller
- Center for Wildlife Health, Department of ForestryWildlife and FisheriesUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
- Department of Biomedical and Diagnostic Sciences, College of Veterinary MedicineUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
| | - Anna C. Peterson
- Center for Wildlife Health, Department of ForestryWildlife and FisheriesUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
| | - William B. Sutton
- Department of Agricultural and Environmental SciencesTennessee State University Nashville Tennessee
| | - Joseph Patrick W. Cusaac
- Center for Wildlife Health, Department of ForestryWildlife and FisheriesUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
| | - Jennifer A. Spatz
- Center for Wildlife Health, Department of ForestryWildlife and FisheriesUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
| | - Louise Rollins‐Smith
- Department of PathologyMicrobiology & ImmunologyVanderbilt University Nashville Tennessee
| | - Laura Reinert
- Department of PathologyMicrobiology & ImmunologyVanderbilt University Nashville Tennessee
| | - Markese Bohanon
- Center for Wildlife Health, Department of ForestryWildlife and FisheriesUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
| | - Lori A. Williams
- North Carolina Wildlife Resources Commission Raleigh North Carolina
| | | | - Matthew J. Gray
- Center for Wildlife Health, Department of ForestryWildlife and FisheriesUniversity of Tennessee Institute of Agriculture Knoxville Tennessee
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91
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Hettyey A, Ujszegi J, Herczeg D, Holly D, Vörös J, Schmidt BR, Bosch J. Mitigating Disease Impacts in Amphibian Populations: Capitalizing on the Thermal Optimum Mismatch Between a Pathogen and Its Host. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00254] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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92
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Lindauer A, May T, Rios-Sotelo G, Sheets C, Voyles J. Quantifying Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans Viability. ECOHEALTH 2019; 16:346-350. [PMID: 31124019 PMCID: PMC6682578 DOI: 10.1007/s10393-019-01414-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 01/20/2019] [Accepted: 04/04/2019] [Indexed: 06/09/2023]
Abstract
The disease chytridiomycosis is responsible for global amphibian declines. Chytridiomycosis is caused by Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), fungal pathogens with stationary and transmissible life stages. Establishing methods that quantify growth and survival of both life stages can facilitate research on the pathophysiology and disease ecology of these pathogens. We tested the efficacy of the MTT assay, a colorimetric test of cell viability, and found it to be a reliable method for quantifying the viability of Bd and Bsal stationary life stages. This method can provide insights into these pathogens' growth and reproduction to improve our understanding of chytridiomycosis.
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Affiliation(s)
- Alexa Lindauer
- Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV, 89557, USA
| | - Tiffany May
- Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV, 89557, USA
| | - Gabriela Rios-Sotelo
- Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV, 89557, USA
| | - Ciara Sheets
- Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV, 89557, USA
| | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV, 89557, USA.
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93
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Del Valle JM, Eisthen HL. Treatment of Chytridiomycosis in Laboratory Axolotls ( Ambystoma mexicanum) and Rough-skinned Newts ( Taricha granulosa). Comp Med 2019; 69:204-211. [PMID: 31142399 DOI: 10.30802/aalas-cm-18-000090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Chytridiomycosis is an infectious disease of amphibians caused by the fungal species Batrachochytrium dendrobatidis and B. salamandrivorans and has been implicated in the population decline of amphibian species worldwide. This case report describes a successful treatment protocol for chytridiomycosis in laboratory-maintained colonies of axolotls (Ambystoma mexicanum) and rough-skinned newts (Taricha granulosa). Over 12 mo, axolotls (n = 12) in a laboratory-reared colony developed multifocal erythematous dermatitis, mainly on the distal limbs and tails. Wild-caught newts handled by the same lab personnel were housed in an adjacent room and occasionally presented with abdominal distension and lethargy. Differentials included poor water quality, pathogen infection, parasitic infestation, and trauma. Antibiotic treatment of animals according to results of bacterial culture and sensitivity, combined with bleach disinfection of aquaria, did not resolve clinical signs. Skin swabs from clinically affected axolotls submitted for a newly available commercial screen were positive for B. dendrobatidis. Additional PCR and sequencing analysis revealed chytrid-positive animals among group-housed newts in 2 clinically unaffected aquaria and suspected PCR-positives for 2 affected newt aquaria and an additional axolotl. Axolotls with skin lesions (n = 2) and newts with abdominal distension and lethargy (n = 2) underwent experimental treatment with itraconazole submersion (0.002% to 0.0025%; 5 min daily for 10 d). This pilot treatment was well tolerated and led to clinical resolution. Subsequent itraconazole treatment of the entire colony led to regrowth of extremities and restoration of normal coloration among axolotls. During treatment, the facility was decontaminated, and additional biosecurity measures were developed. PCR results after the pilot treatment and subsequent full-colony treatments (at 1 wk, 1 mo, and 6 mo after treatment) were negative for the presence of B. dendrobatidis. Because chytridiomycosis is a reportable animal disease in our state, colonies officially remained quarantined until negative PCR results were obtained at least 6 mo after treatment.
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Affiliation(s)
| | - Heather L Eisthen
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan,
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Knepper J, Lüddecke T, Preißler K, Vences M, Schulz S. Isolation and Identification of Alkaloids from Poisons of Fire Salamanders ( Salamandra salamandra). JOURNAL OF NATURAL PRODUCTS 2019; 82:1319-1324. [PMID: 31074997 DOI: 10.1021/acs.jnatprod.9b00065] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Fire salamanders ( Salamandra salamandra) are conspicuously colored amphibians secreting a skin poison that contains unique steroid alkaloids such as samandarine (1) and samadarone (2), exhibiting toxic as well as antimicrobial activities. Because of their antipredatory and anti-infectious functions, alkaloids from Salamandra poison are of interest with regard to the threat that the lethal fungus Batrachochytrium salamandrivorans ( Bsal) poses to salamanders. Nevertheless, reliable data on the biological activity of Salamandra alkaloids are scarce, in part due to the difficulty to obtain and study those substances. Thus, isolation of pure salamander alkaloids is an important task that might directly contribute to the understanding of Bsal infections. Here we present a noninvasive isolation procedure for samandarine (1) and O-acetylsamandarine (3), as well as for two new alkaloids, O-3-hydroxybutanoylsamandarine (4) and samanone (6), using HPLC. For the first time, high-field NMR data are presented for these alkaloids. Analysis using GC/MS and ESI+-MS, provided important information on the structural variability of these salamander alkaloids.
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Affiliation(s)
- Janosch Knepper
- Institute of Organic Chemistry , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| | - Tim Lüddecke
- Animal Venomics Research Group , Fraunhofer Institute for Molecular Biology and Applied Ecology , Winchesterstraße 2 , 35394 Gießen , Germany
- Zoological Institute , Technische Universität Braunschweig , Mendelssohnstraße 4 , 38106 Braunschweig , Germany
| | - Kathleen Preißler
- Zoological Institute , Technische Universität Braunschweig , Mendelssohnstraße 4 , 38106 Braunschweig , Germany
| | - Miguel Vences
- Zoological Institute , Technische Universität Braunschweig , Mendelssohnstraße 4 , 38106 Braunschweig , Germany
| | - Stefan Schulz
- Institute of Organic Chemistry , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
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95
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Ross AA, Rodrigues Hoffmann A, Neufeld JD. The skin microbiome of vertebrates. MICROBIOME 2019; 7:79. [PMID: 31122279 PMCID: PMC6533770 DOI: 10.1186/s40168-019-0694-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/08/2019] [Indexed: 05/05/2023]
Abstract
The skin constitutes the primary physical barrier between vertebrates and their external environment. Characterization of skin microorganisms is essential for understanding how a host evolves in association with its microbial symbionts, modeling immune system development, diagnosing illnesses, and exploring the origins of potential zoonoses that affect humans. Although many studies have characterized the human microbiome with culture-independent techniques, far less is known about the skin microbiome of other mammals, amphibians, birds, fish, and reptiles. The aim of this review is to summarize studies that have leveraged high-throughput sequencing to better understand the skin microorganisms that associate with members of classes within the subphylum Vertebrata. Specifically, links will be explored between the skin microbiome and vertebrate characteristics, including geographic location, biological sex, animal interactions, diet, captivity, maternal transfer, and disease. Recent literature on parallel patterns between host evolutionary history and their skin microbial communities, or phylosymbiosis, will also be analyzed. These factors must be considered when designing future microbiome studies to ensure that the conclusions drawn from basic research translate into useful applications, such as probiotics and successful conservation strategies for endangered and threatened animals.
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Affiliation(s)
- Ashley A Ross
- University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
- Present address: Ontario Veterinary College, University of Guelph, 419 Gordon St, Guelph, Ontario, N1G 2W1, Canada
| | - Aline Rodrigues Hoffmann
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 660 Raymond Stotzer Pkwy, College Station, TX, USA
| | - Josh D Neufeld
- University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
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96
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Sabino-Pinto J, Martel A, Pasmans F, Steinfartz S, Vences M. Pooling skin swabs does not inhibit qPCR detection of amphibian chytrid infection. PLoS One 2019; 14:e0214405. [PMID: 30939146 PMCID: PMC6445426 DOI: 10.1371/journal.pone.0214405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/12/2019] [Indexed: 11/18/2022] Open
Abstract
Immediate and reliable pathogen detection in large numbers of samples is essential in wildlife disease monitoring and is often realized by DNA-based techniques. Pooling samples increases processing efficiency and reduces processing costs, and has been suggested as a viable technique for quantitative PCR detection of fungal amphibian pathogens of the genus Batrachochytrium. For these fungi, this diagnostic method has been validated by in vitro set ups that provided controlled test conditions but did not take into account potential effects from amphibian skin compounds (e.g. skin secretions and Microbiota) on the approach. Some of these skin compounds are known to cause PCR inhibition in single sample applications and could lead to false negative reactions and thereby hamper pathogen detection. In this study we examined the effect of skin compounds on the pooled extraction method by swabbing individuals of seven amphibian species (one Anura and six Caudata) prior to the inoculation of the swabs with chytrid zoospores. For each species, swabs were extracted in pools of different sizes (from one to four swabs) with only one swab per pool being inoculated with zoospores. There were no significant differences regarding the ability to detect zoospores when comparing pool sizes for any species, with a tendency for more false negatives when the inoculated swab had been inoculated with a single zoospore. This study provides further in vivo evidence for the viability of the pooled extraction method for DNA-based detection of pathogens.
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Affiliation(s)
- Joana Sabino-Pinto
- Zoological Institute, Braunschweig University of Technology, Braunschweig, Germany
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Sebastian Steinfartz
- Zoological Institute, Braunschweig University of Technology, Braunschweig, Germany.,University of Leipzig, Institute of Biology, Molecular Evolution and Systematics of Animals, Leipzig, Germany
| | - Miguel Vences
- Zoological Institute, Braunschweig University of Technology, Braunschweig, Germany
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97
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Longo AV, Fleischer RC, Lips KR. Double trouble: co-infections of chytrid fungi will severely impact widely distributed newts. Biol Invasions 2019. [DOI: 10.1007/s10530-019-01973-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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98
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Apparent absence of Batrachochytrium salamandrivorans in wild urodeles in the United Kingdom. Sci Rep 2019; 9:2831. [PMID: 30862900 PMCID: PMC6414544 DOI: 10.1038/s41598-019-39338-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 01/18/2019] [Indexed: 11/09/2022] Open
Abstract
Whether an infectious disease threat to wildlife arises from pathogen introduction or the increased incidence of an already-present agent informs mitigation policy and actions. The prior absence of a pathogen can be difficult to establish, particularly in free-living wildlife. Subsequent to the epidemic emergence of the fungus, Batrachochytrium salamandrivorans (Bsal), in mainland Europe in 2010 and prior to its detection in captive amphibians in the United Kingdom (UK), we tested archived skin swabs using a Bsal-specific qPCR. These samples had been collected in 2011 from 2409 wild newts from ponds across the UK. All swabs were negative for Bsal. Bayesian hierarchical modelling suggests that Bsal was absent from, or present at very low levels in, these ponds at the time of sampling. Additionally, surveillance of newt mortality incidents, 2013-2017, failed to detect Bsal. As this pathogen has been shown to be widespread in British captive amphibian collections, there is an urgent need to raise awareness of the importance of effective biosecurity measures, especially amongst people with captive amphibians, to help minimise the risk of Bsal spreading to the wild. Continued and heightened wild amphibian disease surveillance is a priority to provide an early warning system for potential incursion events.
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Kueneman JG, Bletz MC, McKenzie VJ, Becker CG, Joseph MB, Abarca JG, Archer H, Arellano AL, Bataille A, Becker M, Belden LK, Crottini A, Geffers R, Haddad CFB, Harris RN, Holden WM, Hughey M, Jarek M, Kearns PJ, Kerby JL, Kielgast J, Kurabayashi A, Longo AV, Loudon A, Medina D, Nuñez JJ, Perl RGB, Pinto-Tomás A, Rabemananjara FCE, Rebollar EA, Rodríguez A, Rollins-Smith L, Stevenson R, Tebbe CC, Vargas Asensio G, Waldman B, Walke JB, Whitfield SM, Zamudio KR, Zúñiga Chaves I, Woodhams DC, Vences M. Community richness of amphibian skin bacteria correlates with bioclimate at the global scale. Nat Ecol Evol 2019; 3:381-389. [DOI: 10.1038/s41559-019-0798-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 01/06/2019] [Indexed: 12/15/2022]
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100
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Basanta MD, Rebollar EA, Parra-Olea G. Potential risk of Batrachochytrium salamandrivorans in Mexico. PLoS One 2019; 14:e0211960. [PMID: 30753218 PMCID: PMC6372179 DOI: 10.1371/journal.pone.0211960] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/24/2019] [Indexed: 02/07/2023] Open
Abstract
The recent decline in populations of European salamanders caused by the chytrid fungus Batrachochytrium salamandrivorans (Bsal) has generated worldwide concern, as it is a major threat to amphibians. Evaluation of the areas most suitable for the establishment of Bsal combined with analysis of the distribution of salamander species could be used to generate and implement biosecurity measures and protect biodiversity at sites with high salamander diversity. In this study, we identified the areas most suitable for the establishment of Bsal in Mexico. Mexico has the second-highest salamander species diversity in the world; thus, we identified areas moderately to highly suitable for the establishment of Bsal with high salamander diversity as potential hotspots for surveillance. Central and Southern Mexico were identified as high-risk zones, with 13 hotspots where 30% of Mexican salamander species occur, including range-restricted species and endangered species. We propose that these hotspots should be thoroughly monitored for the presence of Bsal to prevent the spread of the pathogen if it is introduced to the country.
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Affiliation(s)
- M. Delia Basanta
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, AP, Tercer Circuito Exterior s/ n, Ciudad Universitaria, Ciudad de México, México
- Posgrado en Ciencias Biológicas, Unidad de Posgrado, Edificio A, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, C.P., Ciudad de México, México
| | - Eria A. Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Gabriela Parra-Olea
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, AP, Tercer Circuito Exterior s/ n, Ciudad Universitaria, Ciudad de México, México
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