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Crim MJ, Hart ML. Health Monitoring for Laboratory Salamanders. Methods Mol Biol 2023; 2562:41-74. [PMID: 36272067 DOI: 10.1007/978-1-0716-2659-7_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Laboratory animal health monitoring programs are necessary to protect animal health and welfare, the validity of experimental data, and human health against zoonotic infections. Health monitoring programs should be designed based on a risk assessment and knowledge about the biology and transmission of salamander pathogens. Both traditional and molecular diagnostic platforms are available for salamanders, and they provide complementary information. A comprehensive approach to health monitoring leverages the advantages of multiple platforms to provide a more complete picture of colony health and pathogen status. This chapter presents key considerations in the design and implementation of a colony health monitoring program for laboratory salamanders, including protocols for necropsy and sample collection.
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2
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Castro Monzon F, Rödel MO, Ruland F, Parra-Olea G, Jeschke JM. Batrachochytrium salamandrivorans' Amphibian Host Species and Invasion Range. ECOHEALTH 2022; 19:475-486. [PMID: 36611108 PMCID: PMC9898388 DOI: 10.1007/s10393-022-01620-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 08/31/2022] [Indexed: 06/17/2023]
Abstract
Batrachochytrium salamandrivorans (Bsal), a species related to the destructive pathogen Batrachochytrium dendrobatidis (Bd), was found and identified in Europe in 2013. Now, a decade later, a large amount of information is available. This includes data from studies in the field, reports of infection in captive amphibians, laboratory studies testing host susceptibility, and data from prospective studies that test for Bsal's presence in a location. We conducted a systematic review of the published literature and compiled a dataset of Bsal tests. We identified 67 species that have been reported positive for Bsal, 20 of which have a threatened conservation status. The distribution of species that have been found with infection encompasses 69 countries, highlighting the potential threat that Bsal poses. We point out where surveillance to detect Bsal have taken place and highlight areas that have not been well monitored. The large number of host species belonging to the families Plethodontidae and Salamandridae suggests a taxonomic pattern of susceptibility. Our results provide insight into the risk posed by Bsal and identifies vulnerable species and areas where surveillance is needed to fill existing knowledge gaps.
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Affiliation(s)
- Federico Castro Monzon
- Institute of Biology, Freie Universität Berlin, Königin-Luise-Str. 1-3, 14195, Berlin, Germany.
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587, Berlin, Germany.
- Berlin-Brandenburg Institute of Advanced Biodiversity Research, Altensteinstr. 34, 14195, Berlin, Germany.
- Department of Zoology, Institute of Biology, Universidad Nacional Autonoma de Mexico, AP 70-153, 04510, Mexico City, Mexico.
| | - Mark-Oliver Rödel
- Berlin-Brandenburg Institute of Advanced Biodiversity Research, Altensteinstr. 34, 14195, Berlin, Germany
- Museum für Naturkunde-Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, 10115, Berlin, Germany
| | - Florian Ruland
- Institute of Biology, Freie Universität Berlin, Königin-Luise-Str. 1-3, 14195, Berlin, Germany
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587, Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research, Altensteinstr. 34, 14195, Berlin, Germany
| | - Gabriela Parra-Olea
- Department of Zoology, Institute of Biology, Universidad Nacional Autonoma de Mexico, AP 70-153, 04510, Mexico City, Mexico
| | - Jonathan M Jeschke
- Institute of Biology, Freie Universität Berlin, Königin-Luise-Str. 1-3, 14195, Berlin, Germany
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587, Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research, Altensteinstr. 34, 14195, Berlin, Germany
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3
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Moubarak M, Fischhoff IR, Han BA, Castellanos AA. A spatially explicit risk assessment of salamander populations to
Batrachochytrium salamandrivorans
in the United States. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
| | | | - Barbara A. Han
- Cary Institute of Ecosystem Studies Millbrook New York USA
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4
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Mantzana-Oikonomaki V, Maan M, Sabino-Pinto J. Wildlife pathogen detection: evaluation of alternative DNA extraction protocols. Biol Methods Protoc 2021; 6:bpab018. [PMID: 34693021 PMCID: PMC8529346 DOI: 10.1093/biomethods/bpab018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 11/14/2022] Open
Abstract
Accurate detection of wildlife pathogens is critical in wildlife disease research. False negatives or positives can have catastrophic consequences for conservation and disease-mitigation decisions. Quantitative polymerase chain reaction is commonly used for molecular detection of wildlife pathogens. The reliability of this method depends on the effective extraction of the pathogen's DNA from host samples. A wildlife disease that has been in the centre of conservationist's attention is the amphibian disease Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Here, we compare the efficiency of a spin column extraction kit (QIAGEN), commonly used in Bd DNA extraction, to an alternative spin column kit (BIOKÈ) used in extractions from other types of samples, which is considerably cheaper but not typically used for Bd DNA extraction. Additionally, we explore the effect of an enzymatic pre-treatment on detection efficiency. Both methods showed similar efficiency when extracting Bd DNA from zoospores from laboratory-created cell-cultures, as well as higher efficiency when combined with the enzymatic pre-treatment. Our results indicate that selecting the optimal method for DNA extraction is essential to ensure minimal false negatives and reduce project costs.
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Affiliation(s)
| | - Martine Maan
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Joana Sabino-Pinto
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
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5
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Bosch J, Martel A, Sopniewski J, Thumsová B, Ayres C, Scheele BC, Velo-Antón G, Pasmans F. Batrachochytrium salamandrivorans Threat to the Iberian Urodele Hotspot. J Fungi (Basel) 2021; 7:jof7080644. [PMID: 34436183 PMCID: PMC8400424 DOI: 10.3390/jof7080644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/02/2021] [Accepted: 08/05/2021] [Indexed: 12/17/2022] Open
Abstract
The recent introduction of the chytrid fungus Batrachochytrium salamandrivorans into northeastern Spain threatens salamander diversity on the Iberian Peninsula. We assessed the current epidemiological situation with extensive field sampling of urodele populations. We then sought to delineate priority regions and identify conservation units for the Iberian Peninsula by estimating the susceptibility of Iberian urodeles using laboratory experiments, evidence from mortality events in nature and captivity and inference from phylogeny. None of the 1395 field samples, collected between 2015 and 2021 were positive for Bsal and no Bsal-associated mortality events were recorded, in contrast to the confirmed occurrence of Bsal outbreak previously described in 2018. We classified five of eleven Iberian urodele species as highly susceptible, predicting elevated mortality and population declines following potential Bsal emergence in the wild, five species as intermediately susceptible with variable disease outcomes and one species as resistant to disease and mortality. We identified the six conservation units (i.e., species or lineages within species) at highest risk and propose priority areas for active disease surveillance and field biosecurity measures. The magnitude of the disease threat identified here emphasizes the need for region-tailored disease abatement plans that couple active disease surveillance to rapid and drastic actions.
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Affiliation(s)
- Jaime Bosch
- Biodiversity Research Institute (IMIB), University of Oviedo-Principality of Asturias-CSIC, 33600 Mieres, Spain;
- Museo Nacional de Ciencias Naturales-CSIC, 28006 Madrid, Spain
- Correspondence: ; Tel.: +34-6-777-724-02
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, B9820 Merelbeke, Belgium; (A.M.); (F.P.)
| | - Jarrod Sopniewski
- Fenner School of Environment and Society, Australian National University, Canberra 2601, Australia; (J.S.); (B.C.S.)
| | - Barbora Thumsová
- Biodiversity Research Institute (IMIB), University of Oviedo-Principality of Asturias-CSIC, 33600 Mieres, Spain;
- Museo Nacional de Ciencias Naturales-CSIC, 28006 Madrid, Spain
- Asociación Herpetologica Española, 28006 Madrid, Spain;
| | - Cesar Ayres
- Asociación Herpetologica Española, 28006 Madrid, Spain;
| | - Ben C. Scheele
- Fenner School of Environment and Society, Australian National University, Canberra 2601, Australia; (J.S.); (B.C.S.)
| | - Guillermo Velo-Antón
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, 4485-661 Vairão, Portugal;
- Grupo GEA, Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, 36310 Vigo, Spain
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, B9820 Merelbeke, Belgium; (A.M.); (F.P.)
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ABSENCE OF BATRACHOCHYTRIUM SALAMANDRIVORANS IN A GLOBAL HOTSPOT FOR SALAMANDER BIODIVERSITY. J Wildl Dis 2021; 57:553-560. [PMID: 33984856 DOI: 10.7589/jwd-d-20-00218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/08/2021] [Indexed: 11/20/2022]
Abstract
Batrachochytrium salamandrivorans (Bsal) is an emerging fungal pathogen that affects salamander and newt populations in Asia and Europe. In the Western Hemisphere, Bsal represents a major threat to endemic amphibian populations, which have not evolved resistance to infection, and which could experience local extinction events such as those observed in European fire salamanders (Salamandra salamandra). We report findings of a survey focusing specifically on wild lungless salamanders in the southeastern US, the most biodiverse location for salamander species globally. Between May 2016 and July 2018, we conducted 25 surveys at 10 sites across three ecoregions in Tennessee, US. Using quantitative (q)PCR, we screened water samples and skin swabs from 137 salamanders in five plethodontid genera. Although single replicates of six samples amplified during qPCR cycling, no samples could be confirmed as positive for the presence of Bsal with 28S rRNA PCR and independent laboratory screening. It is probable that we found false positive results, as reported by other researchers using the same assay. We offer recommendations for future monitoring efforts.
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7
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Dual Detection of the Chytrid Fungi Batrachochytrium spp. with an Enhanced Environmental DNA Approach. J Fungi (Basel) 2021; 7:jof7040258. [PMID: 33808405 PMCID: PMC8065926 DOI: 10.3390/jof7040258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 01/24/2023] Open
Abstract
Environmental DNA (eDNA) is becoming an indispensable tool in biodiversity monitoring, including the monitoring of invasive species and pathogens. Aquatic chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal) are major threats to amphibians. However, the use of eDNA for detecting these pathogens has not yet become widespread, due to technological and economic obstacles. Using the enhanced eDNA approach (a simple and cheap sampling protocol) and the universally accepted qPCR assay, we confirmed the presence of Bsal and Bd in previously identified sites in Spain, including four sites that were new for Bsal. The new approach was successfully tested in laboratory conditions using manufactured gene fragments (gBlocks) of the targeted DNA sequence. A comparison of storage methods showed that samples kept in ethanol had the best DNA yield. Our results showed that the number of DNA copies in the Internal Transcribed Spacer region was 120 copies per Bsal cell. Eradication of emerging diseases requires quick and cost-effective solutions. We therefore performed cost-efficiency analyses of standard animal swabbing, a previous eDNA approach, and our own approach. The procedure presented here was evaluated as the most cost-efficient. Our findings will help to disseminate information about efforts to prevent the spread of chytrid fungi.
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8
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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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9
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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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10
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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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11
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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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12
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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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13
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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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14
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Ossiboff RJ, Towe AE, Brown MA, Longo AV, Lips KR, Miller DL, Carter ED, Gray MJ, Frasca S. Differentiating Batrachochytrium dendrobatidis and B. salamandrivorans in Amphibian Chytridiomycosis Using RNAScope ® in situ Hybridization. Front Vet Sci 2019; 6:304. [PMID: 31572738 PMCID: PMC6751264 DOI: 10.3389/fvets.2019.00304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 08/28/2019] [Indexed: 12/25/2022] Open
Abstract
Batrachochytrium dendrobatidis and B. salamandrivorans are important amphibian pathogens responsible for morbidity and mortality in free-ranging and captive frogs, salamanders, and caecilians. While B. dendrobatidis has a widespread global distribution, B. salamandrivorans has only been detected in amphibians in Asia and Europe. Although molecular detection methods for these fungi are well-characterized, differentiation of the morphologically similar organisms in the tissues of affected amphibians is incredibly difficult. Moreover, an accurate tool to identify and differentiate Batrachochytrium in affected amphibian tissues is essential for a specific diagnosis of the causative agent in chytridiomycosis cases. To address this need, an automated dual-plex chromogenic RNAScope®in situ hybridization (ISH) assay was developed and characterized for simultaneous detection and differentiation of B. dendrobatidis and B. salamandrivorans. The assay, utilizing double Z target probe pairs designed to hybridize to 28S rRNA sequences, was specific for the identification of both organisms in culture and in formalin-fixed paraffin-embedded amphibian tissues. The assay successfully identified organisms in tissue samples from five salamander and one frog species preserved in formalin for up to 364 days and was sensitive for the detection of Batrachochytrium in animals with qPCR loads as low as 1.1 × 102 zoospores/microliter. ISH staining of B. salamandrivorans also highlighted the infection of dermal cutaneous glands, a feature not observed in amphibian B. dendrobatidis cases and which may play an important role in B. salamandrivorans pathogenesis in salamanders. The developed ISH assay will benefit both amphibian chytridiomycosis surveillance projects and pathogenesis studies by providing a reliable tool for Batrachochytrium differentiation in tissues.
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Affiliation(s)
- Robert J Ossiboff
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Anastasia E Towe
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Melissa A Brown
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL, United States.,Department of Biology, University of Maryland College Park, College Park, MD, United States
| | - Karen R Lips
- Department of Biology, University of Maryland College Park, College Park, MD, United States
| | - Debra L Miller
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, United States.,Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - E Davis Carter
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - Matthew J Gray
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - Salvatore Frasca
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
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15
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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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16
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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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