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Wan B, Chen G, Poon ESK, Fung HS, Lau A, Sin SYW. Environmental factors and host sex influence the skin microbiota structure of Hong Kong newt (Paramesotriton hongkongensis) in a coldspot of chytridiomycosis in subtropical East Asia. Integr Zool 2024. [PMID: 38872359 DOI: 10.1111/1749-4877.12855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Chytridiomycosis, an infectious skin disease caused by the chytrid fungi, Batrachochytrium dendrobatidis and B. salamandrivorans, poses a significant threat to amphibian biodiversity worldwide. Antifungal bacteria found on the skin of chytrid-resistant amphibians could potentially provide defense against chytridiomycosis and lower mortality rates among resistant individuals. The Hong Kong newt (Paramesotriton hongkongensis) is native to East Asia, a region suspected to be the origin of chytrids, and has exhibited asymptomatic infection, suggesting a long-term coexistence with the chytrids. Therefore, the skin microbiota of this resistant species warrant investigation, along with other factors that can affect the microbiota. Among the 149 newts sampled in their natural habitats in Hong Kong, China, putative antifungal bacteria were found in all individuals. There were 314 amplicon sequence variants distributed over 25 genera of putative antifungal bacteria; abundant ones included Acinetobacter, Flavobacterium, and Novosphingobium spp. The skin microbiota compositions were strongly influenced by the inter-site geographical distances. Despite inter-site differences, we identified some core skin microbes across sites that could be vital to P. hongkongensis. The dominant cores included the family Comamonadaceae, family Chitinophagaceae, and class Betaproteobacteria. Moreover, habitat elevation and host sex also exhibited significant effects on skin microbiota compositions. The antifungal bacteria found on these newts offer an important resource for conservation against chytridiomycosis, such as developing probiotic treatments for susceptible species.
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Affiliation(s)
- Bowen Wan
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Guoling Chen
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Emily Shui Kei Poon
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Hon Shing Fung
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Anthony Lau
- Science Unit, Lingnan University, Hong Kong, China
| | - Simon Yung Wa Sin
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
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Bacigalupe LD, Solano‐Iguaran JJ, Longo AV, Gaitán‐Espitia JD, Valenzuela‐Sánchez A, Alvarado‐Rybak M, Azat C. Nor climate nor human impact factors: Chytrid infection shapes the skin bacterial communities of an endemic amphibian in a biodiversity hotspot. Ecol Evol 2024; 14:e11249. [PMID: 38590552 PMCID: PMC10999949 DOI: 10.1002/ece3.11249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
The bacterial communities of the amphibian skin (i.e., the bacteriome) are critical to the host's innate immune system. However, it is unclear how different drivers can alter this function by modulating the bacteriome's structure. Our aim was to assess the extent to which different host attributes and extrinsic factors influence the structure of the bacterial communities of the skin. Skin bacterial diversity was examined in 148 individuals of the four-eyed frog (Pleurodema thaul) from 16 localities spanning almost 1800 km in latitude. The richness and beta diversity of bacterial families and the richness and abundance of Bd-inhibitory bacterial genera were used to describe their structure. Predictors associated with the host (developmental stage, genetic lineage, individual Batrachochytrium dendrobatidis [Bd] infection status) and the landscape (current climate, degree of anthropogenic disturbance) were used in the statistical modeling in an information theoretical approach. Bd infection and host developmental stage were the only predictors affecting bacteriome richness, with Bd+ individuals and postmetamorphic stages (adults and juveniles) having higher richness than Bd- ones and tadpoles. High diversity in Bd+ individuals is not driven by bacterial genera with known anti-Bd properties. Beta diversity was not affected by Bd infection and was mainly a consequence of bacterial family turnover rather than nestedness. Finally, for those bacterial genera known to have inhibitory effects on chytrid, Bd+ individuals had a slightly higher diversity than Bd- ones. Our study confirms an association between Bd infection and the host developmental stage with the bacterial communities of the skin of P. thaul. Unexpectedly, macroclimate and human impact factors do not seem to play a role in shaping the amphibian skin microbiome. Our study exemplifies that focusing on a single host-parasite system over a large geographic scale can provide essential insights into the factors driving host-parasite-bacteriome interactions.
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Affiliation(s)
| | - Jaiber J. Solano‐Iguaran
- Instituto de Ciencias Ambientales y EvolutivasUniversidad Austral de ChileValdiviaChile
- Departamento de Salud HidrobiológicaInstituto de Fomento PesqueroPuerto MonttChile
| | - Ana V. Longo
- Department of BiologyUniversity of FloridaGainesvilleFloridaUSA
| | - Juan D. Gaitán‐Espitia
- School of Biological Sciences and the SWIRE Institute of Marine ScienceThe University of Hong KongHong KongSARChina
| | | | - Mario Alvarado‐Rybak
- Núcleo de Ciencias Aplicadas en Ciencias Veterinarias y AgronómicasUniversidad de Las AméricasSantiagoChile
| | - Claudio Azat
- Sustainability Research Centre & PhD in Conservation MedicineUniversidad Andres BelloSantiagoChile
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Mantzana-Oikonomaki V, Desreveaux A, Preißler K, Maan ME, Spitzen-van der Sluijs A, Sabino-Pinto J. FIRST RECORD OF BATRACHOCHYTRIUM DENDROBATIDIS IN THE NORTHERN NETHERLANDS. J Parasitol 2024; 110:11-16. [PMID: 38232760 DOI: 10.1645/22-126] [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: 01/19/2024] Open
Abstract
Batrachochytrium dendrobatidis (Bd) infects amphibians and has been linked to the decline of hundreds of anuran amphibians all over the world. In the province of Groningen in the Netherlands, this fungal pathogen was not detected before this study. To determine whether Groningen was Bd-free, we surveyed 12 locations in this province in 2020 and 2021. Samples were then used to quantify the presence of Bd with a qPCR assay. In total, 2 out of 110 (∼0.02%) collected in 2020 and 11 out of 249 samples collected in 2021 tested positive for Bd. Infected amphibians were found in 4 out of the 12 sites, and the prevalence of Bd was estimated at 4% for both years combined. Our study provides the first record of Bd in Groningen, and we hypothesize that Bd is present throughout the Netherlands in regions currently considered "Bd-free." Furthermore, we warn scientists and policymakers to be apprehensive when calling a site free from Bd when sampling is limited or not recent.
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Affiliation(s)
- Vasiliki Mantzana-Oikonomaki
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Anne Desreveaux
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Kathleen Preißler
- Institute of Biology, Molecular Evolution and Systematics of Animals, University of Leipzig, Talstraße 33, 04103 Leipzig, Germany
| | - Martine E Maan
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Annemarieke Spitzen-van der Sluijs
- Reptile, Amphibian and Fish Conservation Netherlands (RAVON), PO Box 1413, 5601 BK Nijmegen, The Netherlands
- Institute for Water and Wetland Research, Animal Ecology and Physiology, Radboud Universiteit, PO Box 9010, 6500 GL Nijmegen, The Netherlands
| | - Joana Sabino-Pinto
- University of Groningen, GELIFES (Groningen Institute for Evolutionary Life Sciences), Nijenborgh 7, 9747 AG Groningen, The Netherlands
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Cortazar-Chinarro M, Richter-Boix A, Rödin-Mörch P, Halvarsson P, Logue JB, Laurila A, Höglund J. Association between the skin microbiome and MHC class II diversity in an amphibian. Mol Ecol 2024; 33:e17198. [PMID: 37933583 DOI: 10.1111/mec.17198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 10/20/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023]
Abstract
Microbiomes play an important role in determining the ecology and behaviour of their hosts. However, questions remain pertaining to how host genetics shape microbiomes, and how microbiome composition influences host fitness. We explored the effects of geography, evolutionary history and host genetics on the skin microbiome diversity and structure in a widespread amphibian. More specifically, we examined the association between bacterial diversity and composition and the major histocompatibility complex class II exon 2 diversity in 12 moor frog (Rana arvalis) populations belonging to two geographical clusters that show signatures of past and ongoing differential selection. We found that while bacterial alpha diversity did not differ between the two clusters, MHC alleles/supertypes and genetic diversity varied considerably depending on geography and evolutionary history. Bacterial alpha diversity was positively correlated with expected MHC heterozygosity and negatively with MHC nucleotide diversity. Furthermore, bacterial community composition showed significant variation between the two geographical clusters and between specific MHC alleles/supertypes. Our findings emphasize the importance of historical demographic events on hologenomic variation and provide new insights into how immunogenetic host variability and microbial diversity may jointly influence host fitness with consequences for disease susceptibility and population persistence.
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Affiliation(s)
- M Cortazar-Chinarro
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
- MEMEG/Department of Biology, Lund University, Lund, Sweden
- Department of Earth Ocean and Atmospheric Sciences, Faculty of Science 2020-2207, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Richter-Boix
- Department of Political and Social Science, Pompeu Fabra University, Barcelona, Spain
| | - P Rödin-Mörch
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - P Halvarsson
- Parasitology/Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - J B Logue
- Aquatic Ecology/Department of Biology, Lund University, Lund, Sweden
- SLU University Library, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - A Laurila
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - J Höglund
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
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Mulla L, Hernández-Gómez O. Wildfires disturb the natural skin microbiota of terrestrial salamanders. Environ Microbiol 2023; 25:2203-2215. [PMID: 37340556 DOI: 10.1111/1462-2920.16452] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 06/04/2023] [Indexed: 06/22/2023]
Abstract
Environmental change can disturb natural associations between wildlife and microbial symbionts, in many cases to the detriment of host health. We used a North American terrestrial salamander system to assess how the skin microbiota of amphibians responds to wildfires. In northern California's redwood/oak forests, we assessed how recent wildfires affected the skin microbiota of three different salamander species (Taricha sp., Batrachoseps attenuatus, and Ensatina eschscholtzii) over two different sampling seasons in 2018 and 2021. We found species-specific responses to wildfire disturbance on the alpha diversity of the skin microbiota of terrestrial salamanders, although burning in general altered the composition of the skin microbiota. The effect of burning on alpha diversities and body condition indices varied by sampling season, suggesting an additional effect of annual climatic conditions on body condition and skin microbiota response. We tested all salamanders for Batrachochytrium dendrobatidis and found four infected individuals in 2018 and none in 2021. Our study documents correlations in the skin microbiota response to an increasing source of disturbance in western North American ecosystems. In addition, our results highlight the need to consider the effects of increased wildfire regimes/intensities and longitudinal effects on wildlife-associated microbiota and animal health.
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Affiliation(s)
- Lubna Mulla
- Department of Natural Sciences and Mathematics, School of Health and Natural Sciences, Dominican University of California, San Rafael, California, USA
| | - Obed Hernández-Gómez
- Department of Natural Sciences and Mathematics, School of Health and Natural Sciences, Dominican University of California, San Rafael, California, USA
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Leonhardt F, Keller A, Arranz Aveces C, Ernst R. From Alien Species to Alien Communities: Host- and Habitat-Associated Microbiomes in an Alien Amphibian. MICROBIAL ECOLOGY 2023; 86:2373-2385. [PMID: 37233803 PMCID: PMC10640505 DOI: 10.1007/s00248-023-02227-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/20/2023] [Indexed: 05/27/2023]
Abstract
Alien species can host diverse microbial communities. These associated microbiomes may be important in the invasion process and their analysis requires a holistic community-based approach. We analysed the skin and gut microbiome of Eleutherodactylus johnstonei from native range populations in St Lucia and exotic range populations in Guadeloupe, Colombia, and European greenhouses along with their respective environmental microbial reservoir through a 16S metabarcoding approach. We show that amphibian-associated and environmental microbial communities can be considered as meta-communities that interact in the assembly process. High proportions of bacteria can disperse between frogs and environment, while respective abundances are rather determined by niche effects driven by the microbial community source and spatial environmental properties. Environmental transmissions appeared to have higher relevance for skin than for gut microbiome composition and variation. We encourage further experimental studies to assess the implications of turnover in amphibian-associated microbial communities and potentially invasive microbiota in the context of invasion success and impacts. Within this novel framework of "nested invasions," (meta-)community ecology thinking can complement and widen the traditional perspective on biological invasions.
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Affiliation(s)
- Franziska Leonhardt
- Faculty of Biology, Technical University of Dresden, 01062, Dresden, Germany.
- Museum of Zoology, Senckenberg Natural History Collections Dresden, Königsbrücker Landstraße 159, 01109, Dresden, Germany.
| | - Alexander Keller
- Faculty of Biology, Ludwig-Maximilians-University of Munich, Geschwister-Scholl-Platz 1, 80539, München, Germany
| | - Clara Arranz Aveces
- Staatliches Museum für Naturkunde Stuttgart, Rosenstein 1, 70173, Stuttgart, Germany
| | - Raffael Ernst
- Faculty of Biology, Technical University of Dresden, 01062, Dresden, Germany.
- Museum of Zoology, Senckenberg Natural History Collections Dresden, Königsbrücker Landstraße 159, 01109, Dresden, Germany.
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Santos B, Martins FMS, Sabino-Pinto J, Licata F, Crottini A. Skin and gut microbiomes of tadpoles vary differently with host and water environment: a short-term experiment using 16S metabarcoding. Sci Rep 2023; 13:16321. [PMID: 37770544 PMCID: PMC10539280 DOI: 10.1038/s41598-023-43340-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 09/22/2023] [Indexed: 09/30/2023] Open
Abstract
The host-microbiome community is influenced by several host and environmental factors. In order to disentangle the individual effects of host and environment, we performed a laboratory experiment to assess the effects of the exposure to different water sources on the skin and gut microbiome of two amphibian species (Pelophylax perezi and Bufo spinosus). We observed that the bacterial communities greatly varied with water environment and host identity. Tadpoles of B. spinosus collected from a waterbody with poorer bacterial diversity exhibited a more diverse skin and gut microbiome after exposed to a richer water source. Tadpoles of P. perezi, originally collected from a richer water environment, exhibited less marked alterations in diversity patterns independently of the water source but showed alterations in gut composition. These results highlight that environment alterations, such as the water source, combined with the host effect, impact the microbiome of amphibian species in different ways; the population history (e.g., previous water environment and habitat) of the host species may also influence future alterations on tadpole microbiome.
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Affiliation(s)
- Bárbara Santos
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal.
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661, Vairão, Portugal.
| | - Filipa M S Martins
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661, Vairão, Portugal
| | - Joana Sabino-Pinto
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Fulvio Licata
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661, Vairão, Portugal
| | - Angelica Crottini
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002, Porto, Portugal
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Villatoro-Castañeda M, Forsburg ZR, Ortiz W, Fritts SR, Gabor CR, Carlos-Shanley C. Exposure to Roundup and Antibiotics Alters Gut Microbial Communities, Growth, and Behavior in Rana berlandieri Tadpoles. BIOLOGY 2023; 12:1171. [PMID: 37759571 PMCID: PMC10525943 DOI: 10.3390/biology12091171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 09/29/2023]
Abstract
The gut microbiome is important for digestion, host fitness, and defense against pathogens, which provides a tool for host health assessment. Amphibians and their microbiomes are highly susceptible to pollutants including antibiotics. We explored the role of an unmanipulated gut microbiome on tadpole fitness and phenotype by comparing tadpoles of Rana berlandieri in a control group (1) with tadpoles exposed to: (2) Roundup® (glyphosate active ingredient), (3) antibiotic cocktail (enrofloxacin, sulfamethazine, trimethoprim, streptomycin, and penicillin), and (4) a combination of Roundup and antibiotics. Tadpoles in the antibiotic and combination treatments had the smallest dorsal body area and were the least active compared to control and Roundup-exposed tadpoles, which were less active than control tadpoles. The gut microbial community significantly changed across treatments at the alpha, beta, and core bacterial levels. However, we did not find significant differences between the antibiotic- and combination-exposed tadpoles, suggesting that antibiotic alone was enough to suppress growth, change behavior, and alter the gut microbiome composition. Here, we demonstrate that the gut microbial communities of tadpoles are sensitive to environmental pollutants, namely Roundup and antibiotics, which may have consequences for host phenotype and fitness via altered behavior and growth.
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Affiliation(s)
- Melissa Villatoro-Castañeda
- Department of Biology, Texas State University, 601 University Dr., San Marcos, TX 78666, USA; (M.V.-C.); (Z.R.F.); (W.O.); (S.R.F.); (C.C.-S.)
| | - Zachery R. Forsburg
- Department of Biology, Texas State University, 601 University Dr., San Marcos, TX 78666, USA; (M.V.-C.); (Z.R.F.); (W.O.); (S.R.F.); (C.C.-S.)
- Archbold Biological Station, 123 Main Dr., Venus, FL 33960, USA
| | - Whitney Ortiz
- Department of Biology, Texas State University, 601 University Dr., San Marcos, TX 78666, USA; (M.V.-C.); (Z.R.F.); (W.O.); (S.R.F.); (C.C.-S.)
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Sarah R. Fritts
- Department of Biology, Texas State University, 601 University Dr., San Marcos, TX 78666, USA; (M.V.-C.); (Z.R.F.); (W.O.); (S.R.F.); (C.C.-S.)
| | - Caitlin R. Gabor
- Department of Biology, Texas State University, 601 University Dr., San Marcos, TX 78666, USA; (M.V.-C.); (Z.R.F.); (W.O.); (S.R.F.); (C.C.-S.)
| | - Camila Carlos-Shanley
- Department of Biology, Texas State University, 601 University Dr., San Marcos, TX 78666, USA; (M.V.-C.); (Z.R.F.); (W.O.); (S.R.F.); (C.C.-S.)
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Gajewski Z, Johnson LR, Medina D, Crainer WW, Nagy CM, Belden LK. Skin bacterial community differences among three species of co-occurring Ranid frogs. PeerJ 2023; 11:e15556. [PMID: 37465150 PMCID: PMC10351513 DOI: 10.7717/peerj.15556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/23/2023] [Indexed: 07/20/2023] Open
Abstract
Skin microbial communities are an essential part of host health and can play a role in mitigating disease. Host and environmental factors can shape and alter these microbial communities and, therefore, we need to understand to what extent these factors influence microbial communities and how this can impact disease dynamics. Microbial communities have been studied in amphibian systems due to skin microbial communities providing some resistance to the amphibian chytrid fungus, Batrachochytrium dendrobatidis. However, we are only starting to understand how host and environmental factors shape these communities for amphibians. In this study, we examined whether amphibian skin bacterial communities differ among host species, host infection status, host developmental stage, and host habitat. We collected skin swabs from tadpoles and adults of three Ranid frog species (Lithobates spp.) at the Mianus River Gorge Preserve in Bedford, New York, USA, and used 16S rRNA gene amplicon sequencing to determine bacterial community composition. Our analysis suggests amphibian skin bacterial communities change across host developmental stages, as has been documented previously. Additionally, we found that skin bacterial communities differed among Ranid species, with skin communities on the host species captured in streams or bogs differing from the communities of the species captured on land. Thus, habitat use of different species may drive differences in host-associated microbial communities for closely-related host species.
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Affiliation(s)
- Zachary Gajewski
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia, United States
| | - Leah R. Johnson
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia, United States
- Department of Statistics, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia, United States
| | - Daniel Medina
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia, United States
| | - William W. Crainer
- Department of Animal Sciences, Cornell University, Ithaca, New York, United States
| | | | - Lisa K. Belden
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia, United States
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Jones KR, Hughey MC, Belden LK. Colonization order of bacterial isolates on treefrog embryos impacts microbiome structure in tadpoles. Proc Biol Sci 2023; 290:20230308. [PMID: 36946107 PMCID: PMC10031419 DOI: 10.1098/rspb.2023.0308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 03/06/2023] [Indexed: 03/23/2023] Open
Abstract
Priority effects, or impacts of colonization order, may have lasting influence on ecological community composition. The embryonic microbiome is subject to stochasticity in colonization order of bacteria. Stochasticity may be especially impactful for embryos developing in bacteria-rich environments, such as the embryos of many amphibians. To determine if priority effects experienced as embryos impacted bacterial community composition in newly hatched tadpoles, we selectively inoculated the embryos of laboratory-raised hourglass treefrogs, Dendropsophus ebraccatus, with bacteria initially isolated from the skin of wild D. ebraccatus adults over 2 days. First, embryos were inoculated with two bacteria in alternating sequences. Next, we evaluated the outcomes of priority effects in an in vitro co-culture assay absent of host factors. We then performed a second embryo experiment, inoculating embryos with one of three bacteria on the first day and a community of five target bacteria on the second. Through 16S rRNA gene amplicon sequencing, we observed relative abundance shifts in tadpole bacteria communities due to priority effects. Our results suggest that the initial bacterial source pools of embryos shape bacterial communities at later life stages; however, the magnitude of those changes is dependent on the host environment and the identity of bacterial colonists.
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Affiliation(s)
- Korin Rex Jones
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
| | - Myra C. Hughey
- Department of Biology, Vassar College, Poughkeepsie, NY 12604, USA
| | - Lisa K. Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
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Loudon AH, Terrell KA, Davis RW, Umile TP, Lipps GJ, Greathouse J, Chapman E, Roblee K, Kleopfer JD, Bales EK, Hyman OJ, Harris RN, Minbiole KPC. Metabolite compositions on skins of eastern hellbenders Cryptobranchus alleganiensis alleganiensis differ with location and captivity. DISEASES OF AQUATIC ORGANISMS 2023; 153:9-16. [PMID: 36727687 DOI: 10.3354/dao03715] [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: 06/18/2023]
Abstract
Eastern hellbenders Cryptobranchus alleganiensis alleganiensis, large aquatic salamanders, are declining over most of their range. The amphibian-killing fungus Batrachochytrium dendrobatidis (Bd) has contributed to global amphibian declines and has been detected on eastern hellbenders, but infection intensities were lower than those of species that are more susceptible to Bd. The factors limiting Bd on hellbenders may include antifungal metabolites produced by their skin microbiota. We used a metabolite fingerprinting technique to noninvasively identify the presence, but not identity, of metabolites associated with eastern hellbenders. We surveyed the skin of wild eastern hellbenders to test whether the composition and richness (i.e. number of metabolites) of their metabolites are explained by Bd status or location. Furthermore, we surveyed for metabolites on captive eastern hellbenders to test whether metabolite compositions were different between captive and wild eastern hellbenders. Bd detection was not associated with either metabolite richness or composition. Both metabolite composition and richness differed significantly on hellbenders from different locations (i.e. states). For metabolite composition, there was a statistical interaction between location and Bd status. Metabolite richness was greater on captive eastern hellbenders compared to wild hellbenders, and metabolite compositions differed between wild and captive eastern hellbenders. The methods we employed to detect metabolite profiles effectively grouped individuals by location even though metabolite composition and richness have high levels of intraspecific variation. Understanding the drivers and functional consequences of assemblages of skin metabolites on amphibian health will be an important step toward understanding the mechanisms that result in disease vulnerability.
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Affiliation(s)
- Andrew H Loudon
- Biology Department, Vancouver Island University, Nanaimo, British Columbia V9R 5S5, Canada
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Kaganer AW, Ossiboff RJ, Keith NI, Schuler KL, Comizzoli P, Hare MP, Fleischer RC, Gratwicke B, Bunting EM. Immune priming prior to pathogen exposure sheds light on the relationship between host, microbiome and pathogen in disease. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220810. [PMID: 36756057 PMCID: PMC9890126 DOI: 10.1098/rsos.220810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 01/04/2023] [Indexed: 06/18/2023]
Abstract
Dynamic interactions between host, pathogen and host-associated microbiome dictate infection outcomes. Pathogens including Batrachochytrium dendrobatidis (Bd) threaten global biodiversity, but conservation efforts are hindered by limited understanding of amphibian host, Bd and microbiome interactions. We conducted a vaccination and infection experiment using Eastern hellbender salamanders (Cryptobranchus alleganiensis alleganiensis) challenged with Bd to observe infection, skin microbial communities and gene expression of host skin, pathogen and microbiome throughout the experiment. Most animals survived high Bd loads regardless of their vaccination status and vaccination did not affect pathogen load, but host gene expression differed based on vaccination. Oral vaccination (exposure to killed Bd) stimulated immune gene upregulation while topically and sham-vaccinated animals did not significantly upregulate immune genes. In early infection, topically vaccinated animals upregulated immune genes but orally and sham-vaccinated animals downregulated immune genes. Bd increased pathogenicity-associated gene expression in late infection when Bd loads were highest. The microbiome was altered by Bd, but there was no correlation between anti-Bd microbe abundance or richness and pathogen burden. Our observations suggest that hellbenders initially generate a vigorous immune response to Bd, which is ineffective at controlling disease and is subsequently modulated. Interactions with antifungal skin microbiota did not influence disease progression.
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Affiliation(s)
- Alyssa W. Kaganer
- Department of Natural Resources and the Environment, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
| | - Robert J. Ossiboff
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Nicole I. Keith
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Biology Department, Hamilton College, Clinton, NY, 13323, USA
| | - Krysten L. Schuler
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Pierre Comizzoli
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
| | - Matthew P. Hare
- Department of Natural Resources and the Environment, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA
| | - Robert C. Fleischer
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Front Royal, VA, 22630, USA
| | - Elizabeth M. Bunting
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
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13
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Martínez-Ugalde E, Ávila-Akerberg V, González Martínez TM, Vázquez Trejo M, Zavala Hernández D, Anaya-Morales SL, Rebollar EA. The skin microbiota of the axolotl Ambystoma altamirani is highly influenced by metamorphosis and seasonality but not by pathogen infection. Anim Microbiome 2022; 4:63. [PMID: 36503640 PMCID: PMC9743558 DOI: 10.1186/s42523-022-00215-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/16/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Microbiomes have been increasingly recognized as major contributors to host health and survival. In amphibians, bacterial members of the skin microbiota protect their hosts by inhibiting the growth of the fungal pathogen Batrachochytrium dendrobatidis (Bd). Even though several studies describe the influence of biotic and abiotic factors over the skin microbiota, it remains unclear how these symbiotic bacterial communities vary across time and development. This is particularly relevant for species that undergo metamorphosis as it has been shown that host physiology and ecology drastically influence diversity of the skin microbiome. RESULTS We found that the skin bacterial communities of the axolotl A. altamirani are largely influenced by the metamorphic status of the host and by seasonal variation of abiotic factors such as temperature, pH, dissolved oxygen and conductivity. Despite high Bd prevalence in these samples, the bacterial diversity of the skin microbiota did not differ between infected and non-infected axolotls, although relative abundance of particular bacteria were correlated with Bd infection intensity. CONCLUSIONS Our work shows that metamorphosis is a crucial process that shapes skin bacterial communities and that axolotls under different developmental stages respond differently to environmental seasonal variations. Moreover, this study greatly contributes to a better understanding of the factors that shape amphibian skin microbiota, especially in a largely underexplored group like axolotls (Mexican Ambystoma species).
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Affiliation(s)
- Emanuel Martínez-Ugalde
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Víctor Ávila-Akerberg
- grid.412872.a0000 0001 2174 6731Instituto de Ciencias Agropecuarias y Rurales, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Tanya M. González Martínez
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Montserrat Vázquez Trejo
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Dalia Zavala Hernández
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Sara Lucia Anaya-Morales
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico ,grid.251313.70000 0001 2169 2489 Department of Biology, University of Mississippi, Oxford, MS USA
| | - Eria A. Rebollar
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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14
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Cevallos MA, Basanta MD, Bello-López E, Escobedo-Muñoz AS, González-Serrano FM, Nemec A, Romero-Contreras YJ, Serrano M, Rebollar EA. Genomic characterization of antifungal Acinetobacter bacteria isolated from the skin of the frogs Agalychnis callidryas and Craugastor fitzingeri. FEMS Microbiol Ecol 2022; 98:6775075. [PMID: 36288213 DOI: 10.1093/femsec/fiac126] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/09/2022] [Accepted: 10/24/2022] [Indexed: 01/21/2023] Open
Abstract
Chytridiomycosis, a lethal fungal disease caused by Batrachochytrium dendrobatidis (Bd), is responsible for population declines and extinctions of amphibians worldwide. However, not all amphibian species are equally susceptible to the disease; some species persist in Bd enzootic regions with no population reductions. Recently, it has been shown that the amphibian skin microbiome plays a crucial role in the defense against Bd. Numerous bacterial isolates with the capacity to inhibit the growth of Batrachochytrium fungi have been isolated from the skin of amphibians. Here, we characterized eight Acinetobacter bacteria isolated from the frogs Agalychnis callidryas and Craugastor fitzingeri at the genomic level. A total of five isolates belonged to Acinetobacter pittii,Acinetobacter radioresistens, or Acinetobactermodestus, and three were not identified as any of the known species, suggesting they are members of new species. We showed that seven isolates inhibited the growth of Bd and that all eight isolates inhibited the growth of the phytopathogen fungus Botrytis cinerea. Finally, we identified the biosynthetic gene clusters that could be involved in the antifungal activity of these isolates. Our results suggest that the frog skin microbiome includes Acinetobacter isolates that are new to science and have broad antifungal functions, perhaps driven by distinct genetic mechanisms.
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Affiliation(s)
- M A Cevallos
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México
| | - M D Basanta
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México.,Department of Biology, University of Nevada Reno, 1664 N Virgina St, Reno, NV 89557, United States
| | - E Bello-López
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México
| | - A S Escobedo-Muñoz
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México
| | - F M González-Serrano
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México
| | - A Nemec
- Laboratory of Bacterial Genetics, Centre for Epidemiology and Microbiology, National Institute of Public Health, Šrobárova 48, 100 00 Prague 10, Czechia.,Department of Medical Microbiology, Second Faculty of Medicine, Charles University, and Motol University Hospital, V Úvalu 84, 150 06 Prague 5, Czechia
| | - Y J Romero-Contreras
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México
| | - M Serrano
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México
| | - E A Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Cuernavaca, Morelos, 62220, México
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15
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Abstract
Temporal changes and transmission patterns in host-associated microbial communities have important implications for host health. The diversity of amphibian skin microbial communities is associated with disease outcome in amphibians exposed to the fungal pathogen Batrachochytrium dendrobatidis (Bd). To successfully develop conservation strategies against Bd, we need a comprehensive understanding of how skin microbes are maintained and transmitted over time within populations. We used 16S rRNA sequence analysis to compare Epipedobates anthonyi frogs housed with one conspecific to frogs housed singly at four time points over the course of 1 year. We found that both α and β diversity of frog skin bacterial communities changed significantly over the course of the experiment. Specifically, we found that bacterial communities of cohabitating frogs became more similar over time. We also observed that some bacterial taxa were differentially abundant between frogs housed singly and frogs housed with a conspecific. These results suggest that conspecific contact may play a role in mediating amphibian skin microbial diversity and that turnover of skin microbial communities can occur across time. Our findings provide rationale for future studies exploring horizontal transmission as a potential mechanism of host-associated microbial maintenance in amphibians.
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Affiliation(s)
- Ariel Kruger
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ, USA
| | - Spencer Roth
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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16
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Estrada A, Medina D, Gratwicke B, Ibáñez R, Belden LK. Body condition, skin bacterial communities and disease status: insights from the first release trial of the limosa harlequin frog,
Atelopus limosus. Proc Biol Sci 2022; 289:20220586. [PMID: 35858072 PMCID: PMC9277274 DOI: 10.1098/rspb.2022.0586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Many endangered amphibian species survive in captive breeding facilities, but there have been few attempts to reintroduce captive-born individuals to rebuild wild populations. We conducted a soft-release trial of limosa harlequin frogs,
Atelopus limosus,
which are highly susceptible to the amphibian chytrid fungus
Batrachochytrium dendrobatidis
(Bd), to understand changes associated with the transition from captivity to the wild. Specifically, we assessed changes in body condition, skin-associated bacterial communities and disease status after release. Frogs were housed individually in field mesocosms and monitored for 27 days. Body condition did not significantly change in the mesocosms, and was similar to, or higher than, that of wild conspecifics at day 27. The skin bacteria of captive-born frogs, based on 16S rRNA gene amplicons, became similar to that of wild conspecifics after 27 days in mesocosms. Prevalence of Bd in wild conspecifics was 13–27%, and 15% of the
A. limosus
in mesocosms became infected with Bd, but no mortality of infected frogs was observed. We conclude that mesocosms are suitable for systematically and repeatedly monitoring amphibians during release trials, and that body condition, the skin microbiome, and Bd status can all change within one month of placement of captive-born individuals back into the wild.
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Affiliation(s)
- Angie Estrada
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
| | - Daniel Medina
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
- Smithsonian Tropical Research Institute, Panama City, Panama
- Sistema Nacional de Investigación, SENACYT, Panama
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Roberto Ibáñez
- Smithsonian Tropical Research Institute, Panama City, Panama
- Sistema Nacional de Investigación, SENACYT, Panama
| | - Lisa K. Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061-0131, USA
- Smithsonian Tropical Research Institute, Panama City, Panama
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17
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McKnight DT, Huerlimann R, Bower DS, Schwarzkopf L, Alford RA, Zenger KR. The interplay of fungal and bacterial microbiomes on rainforest frogs following a disease outbreak. Ecosphere 2022. [DOI: 10.1002/ecs2.4037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Donald T. McKnight
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Roger Huerlimann
- College of Science and Engineering James Cook University Townsville Queensland Australia
- Marine Climate Change Unit Okinawa Institute of Science and Technology Onnason Okinawa Japan
| | - Deborah S. Bower
- College of Science and Engineering James Cook University Townsville Queensland Australia
- School of Environmental and Rural Science University of New England Armidale New South Wales Australia
| | - Lin Schwarzkopf
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Ross A. Alford
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Kyall R. Zenger
- College of Science and Engineering James Cook University Townsville Queensland Australia
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18
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Shu Y, Jiang H, Yuen CNT, Wang W, He J, Zhang H, Liu G, Wei L, Chen L, Wu H. Microcystin-leucine arginine induces skin barrier damage and reduces resistance to pathogenic bacteria in Lithobates catesbeianus tadpoles. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 238:113584. [PMID: 35512477 DOI: 10.1016/j.ecoenv.2022.113584] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/22/2022] [Accepted: 04/27/2022] [Indexed: 06/14/2023]
Abstract
Despite the importance of the skin mucosal barrier and commensal microbiota for the health of amphibians, the potential of environmental contaminants to disrupt the skin mucosal barrier and microbiota have rarely been studied in toxicology. In this study, tadpoles (Lithobates catesbeianus) were exposed to 0, 0.5, and 2 μg/L of microcystin-leucine arginine (MC-LR) for 30 days to explore the impacts of environmentally realistic MC-LR concentrations on the physical skin barrier, immune barrier, commensal microbiota, and skin resistance to pathogenic bacterial invasion. MC-LR exposure significantly reduced the collagen fibrils in the dermis of skin tissues and down-regulated tight junction and stratum corneum-related gene transcriptions, suggesting the damage caused by MC-LR to the physical barrier of the skin. Increased skin eosinophils and upregulated transcriptions of inflammation-related genes in the exposed tadpoles underline the development of skin inflammation resulting from MC-LR exposure even at environmentally realistic concentrations. Comparative transcriptome and immunobiochemical analyses found that antimicrobial peptides (Brevinin-1PLc, Brevinin-2GHc, and Ranatuerin-2PLa) and lysozyme were down-regulated in the exposed groups, while complement, pattern recognition receptor, and specific immune processes were up-regulated. However, the content of endotoxin lipopolysaccharide produced by bacteria increased in a dose-dependent pattern. The disc diffusion test showed a reduced ability of skin supernatant to inhibit pathogenic bacteria in the exposed groups. Analysis of microbial 16 S rRNA gene by high-throughput sequencing revealed that MC-LR interfered with the abundance, composition, and diversity of the skin commensal microbiota, which favored the growth of pathogen-containing genera Rhodococcus, Acinetobacter, and Gordonibacter. In summary, the current study provides the first clues about the impact of MC-LR on the integrity and function of skin barrier of amphibians. These new toxicological evidences can facilitate a more comprehensive evaluation of the ecological risk of MC-LR to amphibians.
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Affiliation(s)
- Yilin Shu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Huiling Jiang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Calista N T Yuen
- State Key Laboratory in Marine Pollution, City University of Hong Kong, Department of Chemistry, Hong Kong, China
| | - Wenchao Wang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Jun He
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Huijuan Zhang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Guangxuan Liu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Luting Wei
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Lianguo Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Hailong Wu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China.
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19
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Hughey MC, Rebollar EA, Harris RN, Ibáñez R, Loftus SC, House LL, Minbiole KPC, Bletz MC, Medina D, Shoemaker WR, Swartwout MC, Belden LK. An experimental test of disease resistance function in the skin-associated bacterial communities of three tropical amphibian species. FEMS Microbiol Ecol 2022; 98:6536914. [PMID: 35212765 DOI: 10.1093/femsec/fiac023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 02/10/2022] [Accepted: 02/23/2022] [Indexed: 11/14/2022] Open
Abstract
Variation in the structure of host-associated microbial communities has been correlated with the occurrence and severity of disease in diverse host taxa, suggesting a key role of the microbiome in pathogen defense. However, whether these correlations are typically a cause or consequence of pathogen exposure remains an open question, and requires experimental approaches to disentangle. In amphibians, infection by the fungal pathogen Batrachochytrium dendrobatidis (Bd) alters the skin microbial community in some host species, whereas in other species, the skin microbial community appears to mediate infection dynamics. In this study, we completed experimental Bd exposures in three species of tropical frogs (Agalychnis callidryas, Dendropsophus ebraccatus, Craugastor fitzingeri) that were sympatric with Bd at the time of the study. For all three species, we identified key taxa within the skin bacterial communities that were linked to Bd infection dynamics. We also measured higher Bd infection intensities in D. ebraccatus and C. fitzingeri that were associated with higher mortality in C. fitzingeri. Our findings indicate that microbially-mediated pathogen resistance is a complex trait that can vary within and across host species, and suggest that symbiont communities that have experienced prior selection for defensive microbes may be less likely to be disturbed by pathogen exposure.
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Affiliation(s)
- Myra C Hughey
- Biology Department; Vassar College; 124 Raymond Avenue; Poughkeepsie, NY 12604; USA
| | - Eria A Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, México
| | - Reid N Harris
- Department of Biology, James Madison University, Harrisonburg, VA, USA
| | - Roberto Ibáñez
- Smithsonian Tropical Research Institute, Panamá, Republic of Panama. Sistema Nacional de Investigación, SENACYT, Panamá, Republic of Panama
| | | | | | | | - Molly C Bletz
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, USA
| | | | - William R Shoemaker
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | | | - Lisa K Belden
- Department of Biological Sciences, VA Tech, Blacksburg, VA, USA
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20
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McGrath-Blaser S, Steffen M, Grafe TU, Torres-Sánchez M, McLeod DS, Muletz-Wolz CR. Early life skin microbial trajectory as a function of vertical and environmental transmission in Bornean foam-nesting frogs. Anim Microbiome 2021; 3:83. [PMID: 34930504 PMCID: PMC8686334 DOI: 10.1186/s42523-021-00147-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 12/07/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The amphibian skin microbiome is an important mediator of host health and serves as a potential source of undiscovered scientifically significant compounds. However, the underlying modalities of how amphibian hosts obtain their initial skin-associated microbiome remains unclear. Here, we explore microbial transmission patterns in foam-nest breeding tree frogs from Southeast Asia (Genus: Polypedates) whose specialized breeding strategy allows for better delineation between vertically and environmentally derived microbes. To facilitate this, we analyzed samples associated with adult frog pairs taken after mating-including adults of each sex, their foam nests, environments, and tadpoles before and after environmental interaction-for the bacterial communities using DNA metabarcoding data (16S rRNA). Samples were collected from frogs in-situ in Brunei, Borneo, a previously unsampled region for amphibian-related microbial diversity. RESULTS Adult frogs differed in skin bacterial communities among species, but tadpoles did not differ among species. Foam nests had varying bacterial community composition, most notably in the nests' moist interior. Nest interior bacterial communities were discrete for each nest and overall displayed a narrower diversity compared to the nest exteriors. Tadpoles sampled directly from the foam nest displayed a bacterial composition less like the nest interior and more similar to that of the adults and nest exterior. After one week of pond water interaction the tadpole skin microbiome shifted towards the tadpole skin and pond water microbial communities being more tightly coupled than between tadpoles and the internal nest environment, but not to the extent that the skin microbiome mirrored the pond bacterial community. CONCLUSIONS Both vertical influence and environmental interaction play a role in shaping the tadpole cutaneous microbiome. Interestingly, the interior of the foam nest had a distinct bacterial community from the tadpoles suggesting a limited environmental effect on tadpole cutaneous bacterial selection at initial stages of life. The shift in the tadpole microbiome after environmental interaction indicates an interplay between underlying host and ecological mechanisms that drive community formation. This survey serves as a baseline for further research into the ecology of microbial transmission in aquatic animals.
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Affiliation(s)
- Sarah McGrath-Blaser
- Department of Biology, University of Florida, 421 Carr Hall, Gainesville, FL 32611 USA
| | - Morgan Steffen
- Department of Biology, James Madison University, 951 Carrier Dr, Harrisonburg, VA 22807 USA
| | - T. Ulmar Grafe
- Universiti Brunei Darussalam, Tungku Link, Gadong, BE 1410 Brunei
| | - María Torres-Sánchez
- Department of Biology, University of Florida, 421 Carr Hall, Gainesville, FL 32611 USA
| | - David S. McLeod
- Department of Biology, James Madison University, 951 Carrier Dr, Harrisonburg, VA 22807 USA
- North Carolina Museum of Natural Sciences, 11 West Jones Street, Raleigh, NC 27601 USA
| | - Carly R. Muletz-Wolz
- Smithsonian National Zoo and Conservation Biology Institute, Center for Conservation Genomics, 3001 Connecticut Ave., Washington, DC 20008 USA
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21
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Buttimer S, Hernández-Gómez O, Rosenblum EB. Skin bacterial metacommunities of San Francisco Bay Area salamanders are structured by host genus and habitat quality. FEMS Microbiol Ecol 2021; 97:6464136. [PMID: 34918086 DOI: 10.1093/femsec/fiab162] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/14/2021] [Indexed: 11/13/2022] Open
Abstract
Host-associated microbial communities can influence physiological processes of macroorganisms, including contributing to infectious disease resistance. For instance, some bacteria that live on amphibian skin produce antifungal compounds that inhibit two lethal fungal pathogens, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Therefore, differences in microbiome composition among host species or populations within a species can contribute to variation in susceptibility to Bd/Bsal. This study applies 16S rRNA sequencing to characterize the skin bacterial microbiomes of three widespread terrestrial salamander genera native to the western United States. Using a metacommunity structure analysis, we identified dispersal barriers for these influential bacteria between salamander families and localities. We also analyzed the effects of habitat characteristics such as percent natural cover and temperature seasonality on the microbiome. We found that certain environmental variables may influence the skin microbial communities of some salamander genera more strongly than others. Each salamander family had a somewhat distinct community of putative anti-Bd skin bacteria, suggesting that salamanders may select for a functional assembly of cutaneous symbionts that could differ in its ability to protect these amphibians from disease. Our observations raise the need to consider host identity and environmental heterogeneity during the selection of probiotics to treat wildlife diseases.
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Affiliation(s)
- Shannon Buttimer
- Department of Environmental Science, Policy, and Management - The University of California, Berkeley, Berkeley, CA, U.S.A.,Department of Biological Sciences - The University of Alabama, Tuscaloosa, AL, U.S.A
| | - Obed Hernández-Gómez
- Department of Environmental Science, Policy, and Management - The University of California, Berkeley, Berkeley, CA, U.S.A.,School of Health and Natural Sciences - Dominican University of California, San Rafael, CA, U.S.A
| | - Erica Bree Rosenblum
- Department of Environmental Science, Policy, and Management - The University of California, Berkeley, Berkeley, CA, U.S.A
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22
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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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23
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Nava-González B, Suazo-Ortuño I, López PB, Maldonado-López Y, Lopez-Toledo L, Raggi L, Parra-Olea G, Alvarado-Díaz J, Gómez-Gil B. Inhibition of Batrachochytrium dendrobatidis Infection by Skin Bacterial Communities in Wild Amphibian Populations. MICROBIAL ECOLOGY 2021; 82:666-676. [PMID: 33598748 DOI: 10.1007/s00248-021-01706-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
Skin-associated bacteria are known to inhibit infection by the fungal pathogen Batrachochytrium dendrobatidis (Bd) in amphibians. It has also been postulated that skin-associated bacterial community is related to Bd infection intensity. However, our understanding of host microbial dynamics and their importance in regulating Bd intensity is limited. We analyzed Bd infection and skin-associated bacteria from two amphibian species, the salamander Ambystoma rivulare and the frog Lithobates spectabilis that co-occurred in a tropical high-altitude site in central Mexico. Sixty-three percent of sampled salamander individuals and 80% of frog individuals tested positive for Bd. Overall, we registered 622 skin-associated bacterial genera, from which 73 are known to have Bd inhibitory effects. These inhibitory taxa represented a relative abundance of 50% in relation to total relative bacterial abundance. Our results indicated that, although sharing some bacterial taxa, bacterial community from the skin of both species was different in taxonomic composition and in relative abundance. Pseudomonas spp. and Stenotrophomonas spp. were among the five most abundant bacterial taxa of both species. Both bacterial taxa inhibit Bd infection. We detected that bacterial richness and relative abundance of inhibitory Bd bacteria were negatively related to intensity of Bd infection independent of species and seasons. Despite the high Bd prevalence in both host species, no dead or sick individuals were registered during field surveys. The relatively low levels of Bd load apparently do not compromise survival of host species. Therefore, our results suggested that individuals analyzed were able to survive and thrive under a dynamic relation with enzootic infections of Bd and their microbiota.
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Affiliation(s)
- Bisbrian Nava-González
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Ireri Suazo-Ortuño
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México.
| | - Perla Bibian López
- Universidad Tecnológica de Morelia, Avenida Vicepresidente Pino Suárez 750, Cd. Industrial, 58200, Morelia, Michoacán, México
| | - Yurixhi Maldonado-López
- CONACyT-Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Leonel Lopez-Toledo
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Luciana Raggi
- CONACYT-Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Gabriela Parra-Olea
- Instituto de Biología, Universidad Nacional Autónoma de México, Cd de México, México
| | - Javier Alvarado-Díaz
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Bruno Gómez-Gil
- CIAD A.C., Mazatlán Unit for Aquaculture, AP 711, Mazatlán, 82000, Sinaloa, México
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24
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Identifying fungal-host associations in an amphibian host system. PLoS One 2021; 16:e0256328. [PMID: 34411153 PMCID: PMC8376043 DOI: 10.1371/journal.pone.0256328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 08/04/2021] [Indexed: 02/07/2023] Open
Abstract
Host-associated microbes can interact with macro-organisms in a number of ways that affect host health. Few studies of host-associated microbiomes, however, focus on fungi. In addition, it is difficult to discern whether a fungal organism found in or on an ectotherm host is associating with it in a durable, symbiotic interaction versus a transient one, and to what extent the habitat and host share microbes. We seek to identify these host-microbe interactions on an amphibian, the Colorado boreal toad (Anaxyrus boreas boreas). We sequenced the ITS1 region of the fungal community on the skin of wild toads (n = 124) from four sites in the Colorado Rocky Mountains, across its physiologically dynamic developmental life stages. We also sampled the common habitats used by boreal toads: water from their natal wetland and aquatic pond sediment. We then examined diversity patterns within different life stages, between host and habitat, and identified fungal taxa that could be putatively host-associated with toads by using an indicator species analysis on toad versus environmental samples. Host and habitat were strikingly similar, with the exception of toad eggs. Post-hatching toad life stages were distinct in their various fungal diversity measures. We identified eight fungal taxa that were significantly associated with eggs, but no other fungal taxa were associated with other toad life stages compared with their environmental habitat. This suggests that although pre- and post-metamorphic toad life stages differ from each other, the habitat and host fungal communities are so similar that identifying obligate host symbionts is difficult with the techniques used here. This approach does, however, leverage sequence data from host and habitat samples to predict which microbial taxa are host-associated versus transient microbes, thereby condensing a large set of sequence data into a smaller list of potential targets for further consideration.
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25
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Mutnale MC, Reddy GS, Vasudevan K. Bacterial Community in the Skin Microbiome of Frogs in a Coldspot of Chytridiomycosis Infection. MICROBIAL ECOLOGY 2021; 82:554-558. [PMID: 33442763 PMCID: PMC8384794 DOI: 10.1007/s00248-020-01669-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/03/2020] [Indexed: 06/12/2023]
Abstract
Chytridiomycosis is a fungal disease caused by the pathogens, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), which has caused declines in amphibian populations worldwide. Asia is considered as a coldspot of infection, since adult frogs are less susceptible to Bd-induced mortality or morbidity. Using the next-generation sequencing approach, we assessed the cutaneous bacterial community composition and presence of anti-Bd bacteria in six frog species from India using DNA isolated from skin swabs. All the six frog species sampled were tested using nested PCR and found Bd negative. We found a total of 551 OTUs on frog skin, of which the bacterial phyla such as Proteobacteria (56.15% average relative abundance) was dominated followed by Actinobacteria (21.98% average relative abundance) and Firmicutes (13.7% average relative abundance). The contribution of Proteobacteria in the anti-Bd community was highest and represented by 175 OTUs. Overall, the anti-Bd bacterial community dominated (51.7% anti-Bd OTUs) the skin microbiome of the frogs. The study highlights the putative role of frog skin microbiome in affording resistance to Bd infections in coldspots of infection.
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Affiliation(s)
- Milind C Mutnale
- Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Gundlapally S Reddy
- Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Karthikeyan Vasudevan
- Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India.
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26
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Belasen AM, Riolo MA, Bletz MC, Lyra ML, Toledo LF, James TY. Geography, Host Genetics, and Cross-Domain Microbial Networks Structure the Skin Microbiota of Fragmented Brazilian Atlantic Forest Frog Populations. Ecol Evol 2021; 11:9293-9307. [PMID: 34306622 PMCID: PMC8293785 DOI: 10.1002/ece3.7594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 08/31/2020] [Accepted: 03/18/2021] [Indexed: 11/09/2022] Open
Abstract
The host-associated microbiome plays a significant role in health. However, the roles of factors such as host genetics and microbial interactions in determining microbiome diversity remain unclear. We examined these factors using amplicon-based sequencing of 175 Thoropa taophora frog skin swabs collected from a naturally fragmented landscape in southeastern Brazil. Specifically, we examined (1) the effects of geography and host genetics on microbiome diversity and structure; (2) the structure of microbial eukaryotic and bacterial co-occurrence networks; and (3) co-occurrence between microeukaryotes with bacterial OTUs known to affect growth of the fungal pathogen Batrachochytrium dendrobatidis (Bd). While bacterial alpha diversity varied by both site type and host MHC IIB genotype, microeukaryotic alpha diversity varied only by site type. However, bacteria and microeukaryote composition showed variation according to both site type and host MHC IIB genotype. Our network analysis showed the highest connectivity when both eukaryotes and bacteria were included, implying that ecological interactions may occur among domains. Lastly, anti-Bd bacteria were not broadly negatively co-associated with the fungal microbiome and were positively associated with potential amphibian parasites. Our findings emphasize the importance of considering both domains in microbiome research and suggest that for effective probiotic strategies for amphibian disease management, considering potential interactions among all members of the microbiome is crucial.
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Affiliation(s)
- Anat M. Belasen
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
| | - Maria A. Riolo
- Center for Complex SystemsUniversity of MichiganAnn ArborMIUSA
| | - Molly C. Bletz
- Department of BiologyUniversity of Massachusetts BostonBostonMAUSA
| | - Mariana L. Lyra
- Instituto de BiociênciasUniversidade Estadual PaulistaRio ClaroBrazil
| | - L. Felipe Toledo
- Laboratório de História Natural de Anfíbios BrasileirosDepartamento de Biologia AnimalInstituto de BiologiaUniversidade Estadual de CampinasCampinasBrazil
| | - Timothy Y. James
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
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27
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Walke JB, Becker MH, Krinos A, Chang EAB, Santiago C, Umile TP, Minbiole KPC, Belden LK. Seasonal changes and the unexpected impact of environmental disturbance on skin bacteria of individual amphibians in a natural habitat. FEMS Microbiol Ecol 2021; 97:6024676. [PMID: 33278302 DOI: 10.1093/femsec/fiaa248] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 12/02/2020] [Indexed: 01/16/2023] Open
Abstract
Amphibians host diverse skin bacteria that have a role in pathogen defense, but these skin communities could change over time and impact this function. Here, we monitored individual Eastern red-spotted newts (Notophthalmus viridescens; N = 17) for 2 years in a field pond enclosure and assessed the effects of season and disturbance on skin bacterial community dynamics. We created disturbances by adding additional pond substrate to the enclosure at two timepoints. We planned to sample the skin bacterial community and metabolite profiles of each newt every 6 weeks; we ultimately sampled eight individuals at least six times. We used 16S rRNA gene amplicon sequencing to characterize the bacterial communities and HPLC-MS for metabolite profiling. We found that disturbance had a dramatic effect on skin bacterial communities and metabolite profiles, while season had an effect only using select metrics. There were seven core bacterial taxa (97% OTUs) that were found on all newts in all seasons, pre- and post-disturbance. Lastly, there was a correlation between bacterial and metabolite profiles post-disturbance, which was not observed pre-disturbance. This longitudinal study suggests that environmental disturbances can have lasting effects on skin bacterial communities that overwhelm seasonal changes, although the core bacteria remain relatively consistent over time.
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Affiliation(s)
- Jenifer B Walke
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Matthew H Becker
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Arianna Krinos
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | | | - Celina Santiago
- Department of Chemistry, Villanova University, Villanova, PA 19085, USA
| | - Thomas P Umile
- Department of Chemistry, Villanova University, Villanova, PA 19085, USA
| | | | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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28
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Proença DN, Fasola E, Lopes I, Morais PV. Characterization of the Skin Cultivable Microbiota Composition of the Frog Pelophylax perezi Inhabiting Different Environments. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18052585. [PMID: 33807539 PMCID: PMC7967507 DOI: 10.3390/ijerph18052585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/25/2021] [Accepted: 02/28/2021] [Indexed: 12/20/2022]
Abstract
Microorganisms that live in association with amphibian skin can play important roles in protecting their host. Within the scenarios of global change, it is important to understand how environmental disturbances, namely, metal pollution, can affect this microbiota. The aim of this study is to recognize core bacteria in the skin cultivable microbiota of the Perez frog (Pelophylax perezi) that are preserved regardless of the environmental conditions in which the frogs live. The characterization of these isolates revealed characteristics that can support their contributions to the ability of frogs to use metal impacted environments. Frog’s skin swabs were collected from P. perezi populations that inhabit a metal-polluted site and three reference (non-metal polluted) sites. Bacterial strains were isolated, identified, and subjected to an acid mine drainage tolerance (AMD) test, collected upstream from a site heavily contaminated with metals, and tested to produce extracellular polymeric substances (exopolysaccharide, EPS). All frog populations had Acinetobacter in their cutaneous cultivable microbiota. Significant growth inhibition was observed in all bacterial isolates exposed to 75% of AMD. EPS production was considered a characteristic of several isolates. The data obtained is a preliminary step but crucial to sustain that the cultivable microbiota is a mechanism for protecting frogs against environmental contamination.
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Affiliation(s)
- Diogo Neves Proença
- Department of Life Sciences and Centre for Mechanical Engineering, Materials and Processes, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal;
| | - Emanuele Fasola
- CESAM and Department of Biology, University of Aveiro, 3810-005 Aveiro, Portugal; (E.F.); (I.L.)
| | - Isabel Lopes
- CESAM and Department of Biology, University of Aveiro, 3810-005 Aveiro, Portugal; (E.F.); (I.L.)
| | - Paula V. Morais
- Department of Life Sciences and Centre for Mechanical Engineering, Materials and Processes, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal;
- Correspondence: ; Tel.: +35-1239240700
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29
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The amphibian microbiome exhibits poor resilience following pathogen-induced disturbance. ISME JOURNAL 2021; 15:1628-1640. [PMID: 33564111 PMCID: PMC8163836 DOI: 10.1038/s41396-020-00875-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/24/2020] [Accepted: 12/07/2020] [Indexed: 12/29/2022]
Abstract
Infectious pathogens can disrupt the microbiome in addition to directly affecting the host. Impacts of disease may be dependent on the ability of the microbiome to recover from such disturbance, yet remarkably little is known about microbiome recovery after disease, particularly in nonhuman animals. We assessed the resilience of the amphibian skin microbial community after disturbance by the pathogen, Batrachochytrium dendrobatidis (Bd). Skin microbial communities of laboratory-reared mountain yellow-legged frogs were tracked through three experimental phases: prior to Bd infection, after Bd infection (disturbance), and after clearing Bd infection (recovery period). Bd infection disturbed microbiome composition and altered the relative abundances of several dominant bacterial taxa. After Bd infection, frogs were treated with an antifungal drug that cleared Bd infection, but this did not lead to recovery of microbiome composition (measured as Unifrac distance) or relative abundances of dominant bacterial groups. These results indicate that Bd infection can lead to an alternate stable state in the microbiome of sensitive amphibians, or that microbiome recovery is extremely slow—in either case resilience is low. Furthermore, antifungal treatment and clearance of Bd infection had the additional effect of reducing microbial community variability, which we hypothesize results from similarity across frogs in the taxa that colonize community vacancies resulting from the removal of Bd. Our results indicate that the skin microbiota of mountain yellow-legged frogs has low resilience following Bd-induced disturbance and is further altered by the process of clearing Bd infection, which may have implications for the conservation of this endangered amphibian.
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30
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Douglas AJ, Hug LA, Katzenback BA. Composition of the North American Wood Frog (Rana sylvatica) Bacterial Skin Microbiome and Seasonal Variation in Community Structure. MICROBIAL ECOLOGY 2021; 81:78-92. [PMID: 32613267 DOI: 10.1007/s00248-020-01550-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
While a number of amphibian skin microbiomes have been characterized, it is unclear how these communities might vary in response to seasonal changes in the environment and the corresponding behaviors that many amphibians exhibit. Given recent studies demonstrating the importance of the skin microbiome in frog innate immune defense against pathogens, investigating how changes in the environment impact the microbial species present will provide a better understanding of conditions that may alter host susceptibility to pathogens in their environment. We sampled the bacterial skin microbiome of North American wood frogs (Rana sylvatica) from two breeding ponds in the spring, along with the bacterial community present in their vernal breeding pools, and frogs from the nearby forest floor in the summer and fall to determine whether community composition differs by sex, vernal pond site, or temporally across season (spring, summer, fall). Taxon relative abundance data reveals a profile of bacterial phyla similar to those previously described on anuran skin, with Proteobacteria, Bacteroidetes, and Actinobacteria dominating the wood frog skin microbiome. Our results indicate that sex had no significant effect on skin microbiota diversity; however, this may be due to our limited female frog sample size. Vernal pool site had a small but significant effect on skin microbiota, but skin-associated communities were more similar to each other than to the communities observed in the frogs' respective pond water. Across seasons, diversity analyses suggest that there are significant differences between the bacterial skin microbiome of frogs from spring and summer/fall groups while the average α-diversity per frog remained consistent. These results illustrate seasonal variation in wood frog skin microbiome structure and highlight the importance of considering temporal trends in an amphibian microbiome, particularly for species whose life history requires recurrent shifts in habitat and behavior.
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Affiliation(s)
- Alexander J Douglas
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Laura A Hug
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Barbara A Katzenback
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
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31
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Ruthsatz K, Lyra ML, Lambertini C, Belasen AM, Jenkinson TS, da Silva Leite D, Becker CG, Haddad CFB, James TY, Zamudio KR, Toledo LF, Vences M. Skin microbiome correlates with bioclimate and Batrachochytrium dendrobatidis infection intensity in Brazil's Atlantic Forest treefrogs. Sci Rep 2020; 10:22311. [PMID: 33339839 PMCID: PMC7749163 DOI: 10.1038/s41598-020-79130-3] [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: 07/15/2020] [Accepted: 12/04/2020] [Indexed: 12/20/2022] Open
Abstract
In Brazil’s Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to the rapid loss of amphibian populations here and worldwide. The impact of Bd on amphibians is determined by the host's immune system, of which the skin microbiome is a critical component. The richness and diversity of such cutaneous bacterial communities are known to be shaped by abiotic factors which thus may indirectly modulate host susceptibility to Bd. This study aimed to contribute to understanding the environment-host–pathogen interaction determining skin bacterial communities in 819 treefrogs (Anura: Hylidae and Phyllomedusidae) from 71 species sampled across the AF. We investigated whether abiotic factors influence the bacterial community richness and structure on the amphibian skin. We further tested for an association between skin bacterial community structure and Bd co-occurrence. Our data revealed that temperature, precipitation, and elevation consistently correlate with richness and diversity of the skin microbiome and also predict Bd infection status. Surprisingly, our data suggest a weak but significant positive correlation of Bd infection intensity and bacterial richness. We highlight the prospect of future experimental studies on the impact of changing environmental conditions associated with global change on environment-host–pathogen interactions in the AF.
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Affiliation(s)
- Katharina Ruthsatz
- Institute of Zoology, Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany. .,Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106, Brunswick, Germany.
| | - Mariana L Lyra
- Laboratório de Herpetologia, Depto de Biodiversidade, Instituto de Biociências and Centro de Aquicultura (CAUNESP), Universidade Estadual Paulista - UNESP, Rio Claro, São Paulo, Brazil
| | - Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, 13083-862, Brazil
| | - Anat M Belasen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853-2701, USA
| | - Thomas S Jenkinson
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Davis, CA, USA
| | - Domingos da Silva Leite
- Laboratório de Antígenos Bacterianos II, Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, Caixa Postal 6109, Campinas, São Paulo, CEP 13083-862, Brazil
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35847, USA
| | - Célio F B Haddad
- Laboratório de Herpetologia, Depto de Biodiversidade, Instituto de Biociências and Centro de Aquicultura (CAUNESP), Universidade Estadual Paulista - UNESP, Rio Claro, São Paulo, Brazil
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853-2701, USA
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, 13083-862, Brazil
| | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106, Brunswick, Germany
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32
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Martin H. C, Ibáñez R, Nothias LF, Caraballo-Rodríguez AM, Dorrestein PC, Gutiérrez M. Metabolites from Microbes Isolated from the Skin of the Panamanian Rocket Frog Colostethus panamansis (Anura: Dendrobatidae). Metabolites 2020; 10:E406. [PMID: 33065987 PMCID: PMC7601193 DOI: 10.3390/metabo10100406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 09/28/2020] [Accepted: 10/09/2020] [Indexed: 01/02/2023] Open
Abstract
The Panamanian rocket frog Colostethus panamansis (family Dendrobatidae) has been affected by chytridiomycosis, a deadly disease caused by the fungus Batrachochytrium dendrobatidis (Bd). While there are still uninfected frogs, we set out to isolate microbes from anatomically distinct regions in an effort to create a cultivable resource within Panama for potential drug/agricultural/ecological applications that perhaps could also be used as part of a strategy to protect frogs from infections. To understand if there are specific anatomies that should be explored in future applications of this resource, we mapped skin-associated bacteria of C. panamansis and their metabolite production potential by mass spectrometry on a 3D model. Our results indicate that five bacterial families (Enterobacteriaceae, Comamonadaceae, Aeromonadaceae, Staphylococcaceae and Pseudomonadaceae) dominate the cultivable microbes from the skin of C. panamansis. The combination of microbial classification and molecular analysis in relation to the anti-Bd inhibitory databases reveals the resource has future potential for amphibian conservation.
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Affiliation(s)
- Christian Martin H.
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Clayton, Panama 0843-01103, Panama;
- Department of Biotechnology, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur 522510, India
| | - Roberto Ibáñez
- Smithsonian Tropical Research Institute, Balboa, Ancon, Panama 0843-03092, Panama;
| | - Louis-Félix Nothias
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA; (L.-F.N.); (A.M.C.-R.); (P.C.D.)
| | - Andrés Mauricio Caraballo-Rodríguez
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA; (L.-F.N.); (A.M.C.-R.); (P.C.D.)
| | - Pieter C. Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA; (L.-F.N.); (A.M.C.-R.); (P.C.D.)
| | - Marcelino Gutiérrez
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Clayton, Panama 0843-01103, Panama;
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Loudon AH, Kurtz A, Esposito E, Umile TP, Minbiole KPC, Parfrey LW, Sheafor BA. Columbia spotted frogs (Rana luteiventris) have characteristic skin microbiota that may be shaped by cutaneous skin peptides and the environment. FEMS Microbiol Ecol 2020; 96:5894915. [DOI: 10.1093/femsec/fiaa168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 08/13/2020] [Indexed: 01/20/2023] Open
Abstract
ABSTRACT
Global amphibian declines due to the fungal pathogen Batrachochytrium dendrobatidis (Bd) have led to questions about how amphibians defend themselves against skin diseases. A total of two amphibian defense mechanisms are antimicrobial peptides (AMPs), a component of amphibian innate immune defense and symbiotic skin bacteria, which can act in synergy. We characterized components of these factors in four populations of Columbia spotted frogs (Rana luteiventris) to investigate their role in disease defense. We surveyed the ability of their AMPs to inhibit Bd, skin bacterial community composition, skin metabolite profiles and presence and intensity of Bd infection. We found that AMPs from R. luteiventris inhibited Bd in bioassays, but inhibition did not correlate with Bd intensity on frogs. R. luteiventris had two prevalent and abundant core bacteria: Rhizobacter and Chryseobacterium. Rhizobacter relative abundance was negatively correlated with AMP's ability to inhibit Bd, but was not associated with Bd status itself. There was no relationship between metabolites and Bd. Bacterial communities and Bd differ by location, which suggests a strong environmental influence. R. luteiventris are dominated by consistent core bacteria, but also house transient bacteria that are site specific. Our emergent hypothesis is that host control and environmental factors shape the microbiota on R. luteiventris.
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Affiliation(s)
- A H Loudon
- Department of Zoology and Biodiversity Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, CA
| | - A Kurtz
- Biology Department, Carroll College, Helena, Montana, 59625-0002, USA
| | - E Esposito
- Biology Department, Carroll College, Helena, Montana, 59625-0002, USA
| | - T P Umile
- Department of Chemistry, Villanova University, Villanova, Pennsylvania, 19085-1603, USA
| | - K P C Minbiole
- Department of Chemistry, Villanova University, Villanova, Pennsylvania, 19085-1603, USA
| | - L W Parfrey
- Department of Zoology and Biodiversity Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, CA
- Department of Botany, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, CA
| | - B A Sheafor
- Biology Department, Carroll College, Helena, Montana, 59625-0002, USA
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Kruger A. Frog Skin Microbiota Vary With Host Species and Environment but Not Chytrid Infection. Front Microbiol 2020; 11:1330. [PMID: 32670233 PMCID: PMC7328345 DOI: 10.3389/fmicb.2020.01330] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 05/25/2020] [Indexed: 01/15/2023] Open
Abstract
Describing the structure and function of the amphibian cutaneous microbiome has gained importance with the spread of Batrachochytrium dendrobatidis (Bd), the fungal pathogen that can cause the skin disease chytridiomycosis. Sampling amphibian skin microbiota is needed to characterize current infection status and to help predict future susceptibility to Bd based on microbial composition since some skin microbes have antifungal capabilities that may confer disease resistance. Here, I use 16S rRNA sequencing to describe the composition and structure of the cutaneous microbiota of six species of amphibians. Frog skin samples were also tested for Bd, and I found 11.8% Bd prevalence among all individuals sampled (n = 76). Frog skin microbiota varied by host species and sampling site, but did not differ among Bd-positive and Bd-negative individuals. These results suggest that bacterial composition reflects host species and the environment, but does not reflect Bd infection among the species sampled here. Of the bacterial OTUs identified using an indicator species analysis as strongly associated with amphibians, significantly more indicator OTUs were putative anti-Bd taxa than would be expected based on the proportion of anti-Bd OTUs among all frog OTUs, suggesting strong associations between host species and anti-Bd OTUs. This relationship may partially explain why some of these frogs are asymptomatic carriers of Bd, but more work is needed to determine the other factors that contribute to interspecific variation in Bd susceptibility. This work provides important insights on inter- and intra-specific variation in microbial community composition, putative function, and disease dynamics in populations of amphibians that appear to be coexisting with Bd.
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Affiliation(s)
- Ariel Kruger
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ, United States
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Rebollar EA, Martínez-Ugalde E, Orta AH. The Amphibian Skin Microbiome and Its Protective Role Against Chytridiomycosis. HERPETOLOGICA 2020. [DOI: 10.1655/0018-0831-76.2.167] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Eria A. Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Emanuel Martínez-Ugalde
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Alberto H. Orta
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
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36
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Goff CB, Walls SC, Rodriguez D, Gabor CR. Changes in physiology and microbial diversity in larval ornate chorus frogs are associated with habitat quality. CONSERVATION PHYSIOLOGY 2020; 8:coaa047. [PMID: 32577287 PMCID: PMC7294888 DOI: 10.1093/conphys/coaa047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/29/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Environmental change associated with anthropogenic disturbance can lower habitat quality, especially for sensitive species such as many amphibians. Variation in environmental quality may affect an organism's physiological health and, ultimately, survival and fitness. Using multiple health measures can aid in identifying populations at increased risk of declines. Our objective was to measure environmental variables at multiple spatial scales and their effect on three indicators of health in ornate chorus frog (Pseudacris ornata) tadpoles to identify potential correlates of population declines. To accomplish this, we measured a glucocorticoid hormone (corticosterone; CORT) profile associated with the stress response, as well as the skin mucosal immune function (combined function of skin secretions and skin bacterial community) and bacterial communities of tadpoles from multiple ponds. We found that water quality characteristics associated with environmental variation, including higher water temperature, conductivity and total dissolved solids, as well as percent developed land nearby, were associated with elevated CORT release rates. However, mucosal immune function, although highly variable, was not significantly associated with water quality or environmental factors. Finally, we examined skin bacterial diversity as it aids in immunity and is affected by environmental variation. We found that skin bacterial diversity differed between ponds and was affected by land cover type, canopy cover and pond proximity. Our results indicate that both local water quality and land cover characteristics are important determinants of population health for ornate chorus frogs. Moreover, using these proactive measures of health over time may aid in early identification of at-risk populations that could prevent further declines and aid in management decisions.
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Affiliation(s)
- Cory B Goff
- Department of Biology, Texas State University, 601 University Dr.
San Marcos, TX 78666, USA
- Department of Biology and Chemistry, Liberty University, 1971
University Blvd. Lynchburg, VA 24515, USA
| | - Susan C Walls
- Wetland and Aquatic Research Center, U.S. Geological Survey, 7920
NW 71st St. Gainesville, FL 32653, USA
| | - David Rodriguez
- Department of Biology, Texas State University, 601 University Dr.
San Marcos, TX 78666, USA
| | - Caitlin R Gabor
- Department of Biology, Texas State University, 601 University Dr.
San Marcos, TX 78666, USA
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37
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Bernardo-Cravo AP, Schmeller DS, Chatzinotas A, Vredenburg VT, Loyau A. Environmental Factors and Host Microbiomes Shape Host-Pathogen Dynamics. Trends Parasitol 2020; 36:616-633. [PMID: 32402837 DOI: 10.1016/j.pt.2020.04.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/11/2020] [Accepted: 04/11/2020] [Indexed: 12/18/2022]
Abstract
Microorganisms are increasingly recognized as ecosystem-relevant components because they affect the population dynamics of hosts. Functioning at the interface of the host and pathogen, skin and gut microbiomes are vital components of immunity. Recent work reveals a strong influence of biotic and abiotic environmental factors (including the environmental microbiome) on disease dynamics, yet the importance of the host-host microbiome-pathogen-environment interaction has been poorly reflected in theory. We use amphibians and the disease chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis to show how interactions between host, host microbiome, pathogen, and the environment all affect disease outcome. Our review provides new perspectives that improve our understanding of disease dynamics and ecology by incorporating environmental factors and microbiomes into disease theory.
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Affiliation(s)
- Adriana P Bernardo-Cravo
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Dirk S Schmeller
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| | - Antonis Chatzinotas
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstrasse 15, 04318, Leipzig, Germany; Leipzig University, Institute of Biology, Johannisallee 21-23, 04103 Leipzig, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Adeline Loyau
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, Stechlin, D-16775, Germany
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38
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Walker DM, Hill AJ, Albecker MA, McCoy MW, Grisnik M, Romer A, Grajal-Puche A, Camp C, Kelehear C, Wooten J, Rheubert J, Graham SP. Variation in the Slimy Salamander (Plethodon spp.) Skin and Gut-Microbial Assemblages Is Explained by Geographic Distance and Host Affinity. MICROBIAL ECOLOGY 2020; 79:985-997. [PMID: 31802185 DOI: 10.1007/s00248-019-01456-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 10/23/2019] [Indexed: 06/10/2023]
Abstract
A multicellular host and its microbial communities are recognized as a metaorganism-a composite unit of evolution. Microbial communities have a variety of positive and negative effects on the host life history, ecology, and evolution. This study used high-throughput amplicon sequencing to characterize the complete skin and gut microbial communities, including both bacteria and fungi, of a terrestrial salamander, Plethodon glutinosus (Family Plethodontidae). We assessed salamander populations, representing nine mitochondrial haplotypes ('clades'), for differences in microbial assemblages across 13 geographic locations in the Southeastern United States. We hypothesized that microbial assemblages were structured by both host factors and geographic distance. We found a strong correlation between all microbial assemblages at close geographic distances, whereas, as spatial distance increases, the patterns became increasingly discriminate. Network analyses revealed that gut-bacterial communities have the highest degree of connectedness across geographic space. Host salamander clade was explanatory of skin-bacterial and gut-fungal assemblages but not gut-bacterial assemblages, unless the latter were analyzed within a phylogenetic context. We also inferred the function of gut-fungal assemblages to understand how an understudied component of the gut microbiome may influence salamander life history. We concluded that dispersal limitation may in part describe patterns in microbial assemblages across space and also that the salamander host may select for skin and gut communities that are maintained over time in closely related salamander populations.
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Affiliation(s)
- Donald M Walker
- Department of Biology, Middle Tennessee State University, PO Box 60, Murfreesboro, TN, 37132, USA.
| | - Aubree J Hill
- Department of Biology, Tennessee Technological University, 1100 N. Dixie Ave, Cookeville, TN, 38505, USA
| | - Molly A Albecker
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Michael W McCoy
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Matthew Grisnik
- Department of Biology, Middle Tennessee State University, PO Box 60, Murfreesboro, TN, 37132, USA
| | - Alexander Romer
- Department of Biology, Middle Tennessee State University, PO Box 60, Murfreesboro, TN, 37132, USA
| | - Alejandro Grajal-Puche
- Department of Biology, Middle Tennessee State University, PO Box 60, Murfreesboro, TN, 37132, USA
| | - Carlos Camp
- Department of Biology, Piedmont College, 1021 Central Avenue, Demorest, GA, 30535, USA
| | - Crystal Kelehear
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Ancon, Panama, Republic of Panama
- Department of Biology, Geology and Physical Sciences, Sul Ross State University, Alpine, TX, 79832, USA
| | - Jessica Wooten
- Department of Biology, Piedmont College, 1021 Central Avenue, Demorest, GA, 30535, USA
| | - Justin Rheubert
- Department of Natural Sciences, The University of Findlay, 1000 N. Main St, Findlay, OH, 45840, USA
| | - Sean P Graham
- Department of Biology, Geology and Physical Sciences, Sul Ross State University, Alpine, TX, 79832, USA
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39
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Tong Q, Hu ZF, Du XP, Bie J, Wang HB. Effects of Seasonal Hibernation on the Similarities Between the Skin Microbiota and Gut Microbiota of an Amphibian (Rana dybowskii). MICROBIAL ECOLOGY 2020; 79:898-909. [PMID: 31820074 DOI: 10.1007/s00248-019-01466-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
Both the gut and skin microbiotas have important functions for amphibians. The gut microbiota plays an important role in both the health and evolution of the host species, whereas the role of skin microbiota in disease resistance is particularly important for amphibians. Many studies have examined the effects of environmental factors on the skin and gut microbiotas, but no study has yet explored the similarities between the skin and gut microbiotas. In this study, the gut and skin microbiotas of Rana dybowskii in summer and winter were investigated via high-throughput Illumina sequencing. The results showed that the alpha diversity of gut and skin microbiotas decreased significantly from summer to winter. In both seasons, the microbial composition and structure differed significantly between the gut and skin, and the similarities between these microbiotas differed between seasons. The pairwise distances between the gut and skin microbiotas were greater in winter than in summer. The ratio of core OTUs and shared OTUs to the sum of the OTUs in the gut and skin microbiotas in summer was significantly higher than that in winter. The similarities between the gut and skin microbiotas are important for understanding amphibian ecology and life history.
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Affiliation(s)
- Qing Tong
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
- Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Harbin, 150030, China
| | - Zong-Fu Hu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xiao-Peng Du
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Jia Bie
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Hong-Bin Wang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
- Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Harbin, 150030, China.
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40
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Barnes EM, Carter EL, Lewis JD. Predicting Microbiome Function Across Space Is Confounded by Strain-Level Differences and Functional Redundancy Across Taxa. Front Microbiol 2020; 11:101. [PMID: 32117131 PMCID: PMC7018939 DOI: 10.3389/fmicb.2020.00101] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/17/2020] [Indexed: 12/30/2022] Open
Abstract
Variation in the microbiome among individual organisms may play a critical role in the relative susceptibility of those organisms to infection, disease, and death. However, predicting microbiome function is difficult because of spatial and temporal variation in microbial diversity, and taxonomic diversity is not predictive of microbiome functional diversity. Addressing this issue may be particularly important when addressing pandemic diseases, such as the global amphibian die-off associated with Bd. Some of the most important factors in probiotic development for disease treatment are whether bacteria with desired function can be found on native amphibians in the local environment. To address this issue, we isolated, sequenced, and assayed the cutaneous bacterial communities of Plethodon cinereus along a gradient of land use change. Our results suggest that cutaneous community composition, but not overall diversity, change with changes in land use, but this does not correspond to significant change in Bd-inhibitory function. We found that Bd-inhibition is a functionally redundant trait, but that level of inhibition varies over phylogenetic, spatial, and temporal scales. This research provides further evidence for the importance of continued examination of amphibian microbial communities across environmental gradients, including biotic and abiotic interactions, when considering disease dynamics.
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Affiliation(s)
- Elle M Barnes
- Department of Biological Sciences, Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, United States.,Department of Biological Sciences and Center for Urban Ecology, Fordham University, Bronx, NY, United States
| | - Erin L Carter
- Department of Biological Sciences and Center for Urban Ecology, Fordham University, Bronx, NY, United States
| | - J D Lewis
- Department of Biological Sciences, Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, United States.,Department of Biological Sciences and Center for Urban Ecology, Fordham University, Bronx, NY, United States
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41
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Kruger A. Functional Redundancy of Batrachochytrium dendrobatidis Inhibition in Bacterial Communities Isolated from Lithobates clamitans Skin. MICROBIAL ECOLOGY 2020; 79:231-240. [PMID: 31165187 DOI: 10.1007/s00248-019-01387-7] [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] [Received: 01/28/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
The cutaneous microbial community can influence the health of amphibians exposed to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that has contributed to recent amphibian declines. Resistance to Bd in amphibian populations is correlated with the presence of anti-Bd cutaneous microbes, which confer disease resistance by inhibiting Bd growth. I aimed to determine if green frogs (Lithobates clamitans), an abundant and widely distributed species in New Jersey, harbored bacteria that inhibit Bd and whether the presence and identity of these microbes varied among sites. I used in vitro challenge assays to determine if bacteria isolated from green frog skin could inhibit or enhance the growth of Bd. I found that green frogs at all sites harbored anti-Bd bacteria. However, there were differences in Bd inhibition capabilities among bacterial isolates identified as the same operational taxonomic unit (OTU), lending support to the idea that phylogenetic relatedness does not always predict Bd inhibition status. Additionally, anti-Bd bacterial richness did not vary by site, but the composition of anti-Bd bacterial taxa was distinct at each site. This suggests that there is functional redundancy of Bd inhibition across unique communities of anti-Bd symbionts found on frogs at different sites. These findings highlight the need to better elucidate the structure-function relationship of microbiomes and their role in disease resistance.
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Affiliation(s)
- Ariel Kruger
- Graduate Program in Ecology and Evolution, Department of Ecology, Evolution, and Natural Resources, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, USA.
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42
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Garcia-Recinos L, Burrowes PA, Dominguez-Bello M. The Skin Microbiota of Eleutherodactylus Frogs: Effects of Host Ecology, Phylogeny, and Local Environment. Front Microbiol 2019; 10:2571. [PMID: 31781069 PMCID: PMC6856660 DOI: 10.3389/fmicb.2019.02571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/23/2019] [Indexed: 01/08/2023] Open
Abstract
Amphibian skin microbiota has a potential protective role against diseases. However, the effects of environmental and host factors on symbiotic bacterial communities are not well understood. Caribbean frogs in the genus Eleutherodactylus represent a case of congeneric species that differ in ecological specialization by the process of adaptive radiation. For a small clade of Eleutherodactylus from Puerto Rico, we investigated the role of local environments, host species, and microhabitat in the composition of their skin microbiome. The potential congruence between microbial communities in hosts that are most closely related phylogenetically was also addressed. We hypothesized that the skin microbiota of Eleutherodactylus frogs would be mostly associated to microhabitat use, but also differ according to locality, and to a lesser extent to host species. To test this hypothesis, we swabbed the skin of a total of 98 adult individuals of seven Eleutherodactylus species distributed in two nearby localities in Puerto Rico, and sequenced the V4 region of the 16S rRNA gene. Results showed that locality had the greatest effect on determining skin bacterial communities of amphibian hosts, but this effect was stronger on the composition (based on presence/absence) than on its structure (based on sequence abundance). The most ecologically distinct host, E. cooki, and the generalist E. coqui presented, respectively, the most dissimilar and similar microbiota compared to other hosts. Host phylogeny showed a weak influence on skin microbiota. Results suggest that both local environment and ecological specialization are structuring the skin bacterial community in these Eleutherodactylus species, but that characteristics intrinsic to species may also render unique hosts the ability to maintain distinct microbiotas.
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Affiliation(s)
- Liza Garcia-Recinos
- Department of Biology, University of Puerto Rico, San Juan, Puerto Rico
- Centro de Estudios Conservacionistas, Universidad de San Carlos de Guatemala, Guatemala, Guatemala
| | | | - Maria Dominguez-Bello
- Department of Biology, University of Puerto Rico, San Juan, Puerto Rico
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, United States
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43
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Hughey MC, Sokol ER, Walke JB, Becker MH, Belden LK. Ecological Correlates of Large-Scale Turnover in the Dominant Members of Pseudacris crucifer Skin Bacterial Communities. MICROBIAL ECOLOGY 2019; 78:832-842. [PMID: 30949751 DOI: 10.1007/s00248-019-01372-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Animals host a wide diversity of symbiotic microorganisms that contribute important functions to host health, and our knowledge of what drives variation in the composition of these complex communities continues to grow. Microbiome studies at larger spatial scales present opportunities to evaluate the contribution of large-scale factors to variation in the microbiome. We conducted a large-scale field study to assess variation in the bacterial symbiont communities on adult frog skin (Pseudacris crucifer), characterized using 16S rRNA gene amplicon sequencing. We found that skin bacterial communities on frogs were less diverse than, and structurally distinct from, the surrounding habitat. Frog skin was typically dominated by one of two bacterial OTUs: at western sites, a Proteobacteria dominated the community, whereas eastern sites were dominated by an Actinobacteria. Using a metacommunity framework, we then sought to identify factors explaining small- and large-scale variation in community structure-that is, among hosts within a pond, and among ponds spanning the study transect. We focused on the presence of a fungal skin pathogen, Batrachochytrium dendrobatidis (Bd) as one potential driver of variation. We found no direct link between skin bacterial community structure and Bd infection status of individual frog hosts. Differences in pond-level community structure, however, were explained by Bd infection prevalence. Importantly, Bd infection prevalence itself was correlated with numerous other environmental factors; thus, skin bacterial diversity may be influenced by a complex suite of extrinsic factors. Our findings indicate that large-scale factors and processes merit consideration when seeking to understand microbiome diversity.
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Affiliation(s)
- Myra C Hughey
- Biology Department, Vassar College, Poughkeepsie, NY, USA.
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA.
| | - Eric R Sokol
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
- Battelle, National Ecological Observatory Network (NEON), Boulder, CO, USA
- Institute of Arctic and Alpine Research (INSTAAR), University of Colorado Boulder, Boulder, CO, USA
| | - Jenifer B Walke
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
- Department of Biology, Eastern Washington University, Cheney, WA, USA
| | - Matthew H Becker
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
- Department of Biology and Chemistry, Liberty University, Lynchburg, VA, USA
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
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44
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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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45
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Jiménez RR, Alvarado G, Estrella J, Sommer S. Moving Beyond the Host: Unraveling the Skin Microbiome of Endangered Costa Rican Amphibians. Front Microbiol 2019; 10:2060. [PMID: 31572313 PMCID: PMC6751270 DOI: 10.3389/fmicb.2019.02060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/21/2019] [Indexed: 01/12/2023] Open
Abstract
Some neotropical amphibians, including a few species in Costa Rica, were presumed to be "extinct" after dramatic population declines in the late 1980s but have been rediscovered in isolated populations. Such populations seem to have evolved a resistance/tolerance to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes a deadly skin disease and is considered one of the main drivers of worldwide amphibian declines. The skin microbiome is an important component of the host's innate immune system and is associated with Bd-resistance. However, the way that the bacterial diversity of the skin microbiome confers protection against Bd in surviving species remains unclear. We studied variation in the skin microbiome and the prevalence of putatively anti-Bd bacterial taxa in four co-habiting species in the highlands of the Juan Castro Blanco National Park in Costa Rica using 16S rRNA amplicon sequencing. Lithobates vibicarius, Craugastor escoces, and Isthmohyla rivularis have recently been rediscovered, whereas Isthmohyla pseudopuma has suffered population fluctuations but has never disappeared. To investigate the life stage at which the protective skin microbiome is shaped and when shifts occur in the diversity of putatively anti-Bd bacteria, we studied the skin microbiome of tadpoles, juveniles and adults of L. vibicarius. We show that the skin bacterial composition of sympatric species and hosts with distinct Bd-infection statuses differs at the phyla, family, and genus level. We detected 94 amplicon sequence variants (ASVs) with putative anti-Bd activity pertaining to distinct bacterial taxa, e.g., Pseudomonas spp., Acinetobacter johnsonii, and Stenotrophomonas maltophilia. Bd-uninfected L. vibicarius harbored 79% more putatively anti-Bd ASVs than Bd-infected individuals. Although microbiome composition and structure differed across life stages, the diversity of putative anti-Bd bacteria was similar between pre- and post-metamorphic stages of L. vibicarius. Despite low sample size, our results support the idea that the skin microbiome is dynamic and protects against ongoing Bd presence in endangered species persisting after their presumed extinction. Our study serves as a baseline to understand the microbial patterns in species of high conservation value. Identification of microbial signatures linked to variation in disease susceptibility might, therefore, inform mitigation strategies for combating the global decline of amphibians.
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Affiliation(s)
- Randall R. Jiménez
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Gilbert Alvarado
- Laboratory of Comparative Wildlife Pathology, School of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, Brazil
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Josimar Estrella
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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46
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Becker CG, Bletz MC, Greenspan SE, Rodriguez D, Lambertini C, Jenkinson TS, Guimarães PR, Assis APA, Geffers R, Jarek M, Toledo LF, Vences M, Haddad CFB. Low-load pathogen spillover predicts shifts in skin microbiome and survival of a terrestrial-breeding amphibian. Proc Biol Sci 2019; 286:20191114. [PMID: 31409249 DOI: 10.1098/rspb.2019.1114] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Wildlife disease dynamics are strongly influenced by the structure of host communities and their symbiotic microbiota. Conspicuous amphibian declines associated with the waterborne fungal pathogen Batrachochytrium dendrobatidis (Bd) have been observed in aquatic-breeding frogs globally. However, less attention has been given to cryptic terrestrial-breeding amphibians that have also been declining in tropical regions. By experimentally manipulating multiple tropical amphibian assemblages harbouring natural microbial communities, we tested whether Bd spillover from naturally infected aquatic-breeding frogs could lead to Bd amplification and mortality in our focal terrestrial-breeding host: the pumpkin toadlet Brachycephalus pitanga. We also tested whether the strength of spillover could vary depending on skin bacterial transmission within host assemblages. Terrestrial-breeding toadlets acquired lethal spillover infections from neighbouring aquatic hosts and experienced dramatic but generally non-protective shifts in skin bacterial composition primarily attributable to their Bd infections. By contrast, aquatic-breeding amphibians maintained mild Bd infections and higher survival, with shifts in bacterial microbiomes that were unrelated to Bd infections. Our results indicate that Bd spillover from even mildly infected aquatic-breeding hosts may lead to dysbiosis and mortality in terrestrial-breeding species, underscoring the need to further investigate recent population declines of terrestrial-breeding amphibians in the tropics.
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Affiliation(s)
- C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35847, USA
| | - Molly C Bletz
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Sasha E Greenspan
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35847, USA
| | - David Rodriguez
- Department of Biology, Texas State University, San Marcos, TX 78666, USA
| | - Carolina Lambertini
- Department of Animal Biology, Universidade Estadual de Campinas, Campinas, SP 13083-865, Brazil
| | - Thomas S Jenkinson
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA 94720, USA
| | - Paulo R Guimarães
- Departamento de Ecologia, Universidade de Sao Paulo, Sao Paulo, SP 05508-090, Brazil
| | - Ana Paula A Assis
- Departamento de Ecologia, Universidade de Sao Paulo, Sao Paulo, SP 05508-090, Brazil
| | - Robert Geffers
- Department of Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, LS 38124, Germany
| | - Michael Jarek
- Department of Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, LS 38124, Germany
| | - Luís Felipe Toledo
- Department of Animal Biology, Universidade Estadual de Campinas, Campinas, SP 13083-865, Brazil
| | - Miguel Vences
- Division of Evolutionary Biology, Zoological Institute, Braunschweig University of Technology, Braunschweig, LS 38106, Germany
| | - Célio F B Haddad
- Department of Zoology and Aquaculture Center (CAUNESP), Universidade Estadual Paulista, Rio Claro, SP 13506-900, Brazil
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47
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Albecker MA, Belden LK, McCoy MW. Comparative Analysis of Anuran Amphibian Skin Microbiomes Across Inland and Coastal Wetlands. MICROBIAL ECOLOGY 2019; 78:348-360. [PMID: 30535916 DOI: 10.1007/s00248-018-1295-9] [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: 07/06/2018] [Accepted: 11/15/2018] [Indexed: 05/16/2023]
Abstract
Amphibians host a community of microbes on their skin that helps resist infectious disease via the dual influence of anti-pathogenic microbial species and emergent community dynamics. Many frogs rely on freshwater habitats, but salinization is rapidly increasing saltwater concentrations in wetlands around the globe, increasing the likelihood that frogs will come into contact with salt-contaminated habitats. Currently, we know little about how increased salt exposure will affect the symbiotic relationship between the skin microbes and frog hosts. To better understand how salt exposure in a natural context affects the frog skin microbiome, we use Hyla cinerea, a North American treefrog species that can inhabit brackish wetlands, to explore three questions. First, we determine the extent that microbial communities in the environment and on frog skin are similar across populations. Second, we assess the microbial species richness and relative abundance on frogs from habitats with different salinity levels to determine how salinity affects the microbiome. Third, we test whether the relative abundances of putatively pathogen-resistant bacterial species differ between frogs from inland and coastal environments. We found that the frog microbiome is more similar among frogs than to the microbial communities found in surface water and soil, but there is overlap between frog skin and the environmental samples. Skin microbial community richness did not differ among populations, but the relative abundances of microbes were different across populations and salinities. We found no differences in the relative abundances of the anti-fungal bacteria Janthinobacterium lividum, the genus Pseudomonas, and Serratia marcescens, suggesting that environmental exposure to saltwater has a limited influence on these putatively beneficial bacterial taxa.
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Affiliation(s)
- Molly A Albecker
- Department of Biology, East Carolina University, Greenville, NC, USA.
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Michael W McCoy
- Department of Biology, East Carolina University, Greenville, NC, USA
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48
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Estrada A, Hughey MC, Medina D, Rebollar EA, Walke JB, Harris RN, Belden LK. Skin bacterial communities of neotropical treefrogs vary with local environmental conditions at the time of sampling. PeerJ 2019; 7:e7044. [PMID: 31275740 PMCID: PMC6590418 DOI: 10.7717/peerj.7044] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 04/27/2019] [Indexed: 12/28/2022] Open
Abstract
The amphibian skin microbiome has been the focus of recent studies aiming to better understand the role of these microbial symbionts in host defense against disease. However, host-associated microbial communities are complex and dynamic, and changes in their composition and structure can influence their function. Understanding temporal variation of bacterial communities on amphibian skin is critical for establishing baselines from which to improve the development of mitigation techniques based on probiotic therapy and provides long-term host protection in a changing environment. Here, we investigated whether microbial communities on amphibian skin change over time at a single site. To examine this, we collected skin swabs from two pond-breeding species of treefrogs, Agalychnis callidryas and Dendropsophus ebraccatus, over 4 years at a single lowland tropical pond in Panamá. Relative abundance of operational taxonomic units (OTUs) based on 16S rRNA gene amplicon sequencing was used to determine bacterial community diversity on the skin of both treefrog species. We found significant variation in bacterial community structure across long and short-term time scales. Skin bacterial communities differed across years on both species and between seasons and sampling days only in D. ebraccatus. Importantly, bacterial community structures across days were as variable as year level comparisons. The differences in bacterial community were driven primarily by differences in relative abundance of key OTUs and explained by rainfall at the time of sampling. These findings suggest that skin-associated microbiomes are highly variable across time, and that for tropical lowland sites, rainfall is a good predictor of variability. However, more research is necessary to elucidate the significance of temporal variation in bacterial skin communities and their maintenance for amphibian conservation efforts.
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Affiliation(s)
- Angie Estrada
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA
| | - Myra C Hughey
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA
| | - Daniel Medina
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA
| | - Eria A Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Jenifer B Walke
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA
| | - Reid N Harris
- Department of Biology, James Madison University, Harrisonburg, VA, USA
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, VA, USA.,Smithsonian Tropical Research Institute, Balboa, Ancón, Panamá, Panamá
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49
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Medina D, Hughey MC, Walke JB, Becker MH, Pontarelli K, Sun S, Badgley B, Belden LK. Amphibian skin fungal communities vary across host species and do not correlate with infection by a pathogenic fungus. Environ Microbiol 2019; 21:2905-2920. [PMID: 31087743 DOI: 10.1111/1462-2920.14682] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 05/10/2019] [Accepted: 05/11/2019] [Indexed: 12/26/2022]
Abstract
Amphibian population declines caused by the fungus Batrachochytrium dendrobatidis (Bd) have prompted studies on the bacterial community that resides on amphibian skin. However, studies addressing the fungal portion of these symbiont communities have lagged behind. Using ITS1 amplicon sequencing, we examined the fungal portion of the skin microbiome of temperate and tropical amphibian species currently coexisting with Bd in nature. We assessed cooccurrence patterns between bacterial and fungal OTUs using a subset of samples for which bacterial 16S rRNA gene amplicon data were also available. We determined that fungal communities were dominated by members of the phyla Ascomycota and Basidiomycota, and also by Chytridiomycota in the most aquatic amphibian species. Alpha diversity of the fungal communities differed across host species, and fungal community structure differed across species and regions. However, we did not find a correlation between fungal diversity/community structure and Bd infection, though we did identify significant correlations between Bd and specific OTUs. Moreover, positive bacterial-fungal cooccurrences suggest that positive interactions between these organisms occur in the skin microbiome. Understanding the ecology of amphibian skin fungi, and their interactions with bacteria will complement our knowledge of the factors influencing community assembly and the overall function of these symbiont communities.
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Affiliation(s)
- Daniel Medina
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Myra C Hughey
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Department of Biology, Vassar College, Poughkeepsie, NY, USA
| | - Jenifer B Walke
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Department of Biology, Eastern Washington University, Cheney, WA, USA
| | - Matthew H Becker
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | | | - Shan Sun
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, USA.,College of Computing and Informatics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Brian Badgley
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
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50
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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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