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Corrie LM, Kuecks-Winger H, Ebrahimikondori H, Birol I, Helbing CC. Transcriptomic profiling of Rana [Lithobates] catesbeiana back skin during natural and thyroid hormone-induced metamorphosis under different temperature regimes with particular emphasis on innate immune system components. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2024; 50:101238. [PMID: 38714098 DOI: 10.1016/j.cbd.2024.101238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/28/2024] [Accepted: 04/30/2024] [Indexed: 05/09/2024]
Abstract
As amphibians undergo thyroid hormone (TH)-dependent metamorphosis from an aquatic tadpole to the terrestrial frog, their innate immune system must adapt to the new environment. Skin is a primary line of defense, yet this organ undergoes extensive remodelling during metamorphosis and how it responds to TH is poorly understood. Temperature modulation, which regulates metamorphic timing, is a unique way to uncover early TH-induced transcriptomic events. Metamorphosis of premetamorphic tadpoles is induced by exogenous TH administration at 24 °C but is paused at 5 °C. However, at 5 °C a "molecular memory" of TH exposure is retained that results in an accelerated metamorphosis upon shifting to 24 °C. We used RNA-sequencing to identify changes in Rana (Lithobates) catesbeiana back skin gene expression during natural and TH-induced metamorphosis. During natural metamorphosis, significant differential expression (DE) was observed in >6500 transcripts including classic TH-responsive transcripts (thrb and thibz), heat shock proteins, and innate immune system components: keratins, mucins, and antimicrobial peptides (AMPs). Premetamorphic tadpoles maintained at 5 °C showed 83 DE transcripts within 48 h after TH administration, including thibz which has previously been identified as a molecular memory component in other tissues. Over 3600 DE transcripts were detected in TH-treated tadpoles at 24 °C or when tadpoles held at 5 °C were shifted to 24 °C. Gene ontology (GO) terms related to transcription, RNA metabolic processes, and translation were enriched in both datasets and immune related GO terms were observed in the temperature-modulated experiment. Our findings have implications on survival as climate change affects amphibia worldwide.
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Affiliation(s)
- Lorissa M Corrie
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Haley Kuecks-Winger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Hossein Ebrahimikondori
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, BC V5Z 4S6, Canada
| | - Inanc Birol
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, BC V5Z 4S6, Canada
| | - Caren C Helbing
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2, Canada.
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Belasen AM, Peek RA, Adams AJ, Russell ID, De León ME, Adams MJ, Bettaso J, Breedveld KGH, Catenazzi A, Dillingham CP, Grear DA, Halstead BJ, Johnson PG, Kleeman PM, Koo MS, Koppl CW, Lauder JD, Padgett-Flohr G, Piovia-Scott J, Pope KL, Vredenburg V, Westphal M, Wiseman K, Kupferberg SJ. Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231270. [PMID: 38298390 PMCID: PMC10827429 DOI: 10.1098/rsos.231270] [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: 08/26/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024]
Abstract
Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog (Rana boylii) inhabits a wide geographical range and variable conditions in rivers of California and Oregon (USA), and is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd). To assess drivers of Bd infections over time and space, we compiled over 2000 datapoints from R. boylii museum specimens (collected 1897-2005) and field samples (2005-2021) spanning 9° of latitude. We observed a south-to-north spread of Bd detections beginning in the 1940s and increase in prevalence from the 1940s to 1970s, coinciding with extirpation from southern latitudes. We detected eight high-prevalence geographical clusters through time that span the species' geographical range. Field-sampled male R. boylii exhibited the highest prevalence, and juveniles sampled in autumn exhibited the highest loads. Bd infection risk was highest in lower elevation rain-dominated watersheds, and with cool temperatures and low stream-flow conditions at the end of the dry season. Through a holistic assessment of relationships between infection risk, geographical context and time, we identify the locations and time periods where Bd mitigation and monitoring will be critical for conservation of this imperilled species.
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Affiliation(s)
- A. M. Belasen
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - R. A. Peek
- California Department of Fish and Wildlife, West Sacramento, CA, USA
| | - A. J. Adams
- Earth Research Institute, University of California, Santa Barbara, CA, USA
| | - I. D. Russell
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - M. E. De León
- Genome Center, University of California, Davis, CA, USA
| | - M. J. Adams
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, USA
| | - J. Bettaso
- Six Rivers National Forest, Lower Trinity Ranger District, USDA Forest Service, P.O. Box 68, Willow Creek, CA, USA
| | | | - A. Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL, USA
| | | | - D. A. Grear
- U.S. Geological Survey, National Wildlife Health Center, Madison, WI, USA
| | - B. J. Halstead
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - P. G. Johnson
- Pinnacles National Park, National Park Service, Paicines, CA, USA
| | - P. M. Kleeman
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - M. S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, CA
| | - C. W. Koppl
- Plumas National Forest, USDA Forest Service, Quincy, CA, USA
| | | | | | - J. Piovia-Scott
- School of Biological Sciences, Washington State University, Vancouver, WA, USA
| | - K. L. Pope
- Pacific Southwest Research Station, USDA Forest Service, Arcata, CA, USA
| | - V. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - M. Westphal
- Central Coast Field Office, United States Bureau of Land Management, Marina, CA, USA
| | - K. Wiseman
- Department of Herpetology, California Academy of Sciences, San Francisco, CA, USA
| | - S. J. Kupferberg
- Department of Integrative Biology, University of California, Berkeley, CA, USA
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3
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Carvalho T, Si C, Clemons RA, Faust E, James TY. Amphibian Hymenochirus boettgeri as an experimental model for infection studies with the chytrid fungus Batrachochytrium dendrobatidis. Virulence 2023; 14:2270252. [PMID: 37823610 PMCID: PMC10614710 DOI: 10.1080/21505594.2023.2270252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023] Open
Abstract
Model organisms are crucial in research as they can provide key insights applicable to other species. This study proposes the use of the amphibian species Hymenochirus boettgeri, widely available through the aquarium trade, as a model organism for the study of chytridiomycosis, a disease caused by the fungus Batrachochytrium dendrobatidis (Bd) and linked to amphibian decline and extinction globally. Currently, no model organisms are used in the study of chytridiomycosis, particularly because of the lack of availability and nonstandardized methods. Thus, laboratories around the world use wild local species to conduct Bd infection experiments, which prevents comparisons between studies and reduces reproducibility. Here, we performed a series of Bd infection assays that showed that H. boettgeri has a dose- and genotype-dependent response, can generalize previous findings on virulence estimates in other species, and can generate reproducible results in replicated experimental conditions. We also provided valuable information regarding H. boettgeri husbandry, including care, housing, reproduction, and heat treatment to eliminate previous Bd infections. Together, our results indicate that H. boettgeri is a powerful and low-ecological-impact system for studying Bd pathogenicity and virulence.
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Affiliation(s)
- Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Catherine Si
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Rebecca A. Clemons
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Evelyn Faust
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Timothy Y. James
- Department of Ecology and Evolutionary Biology, University of Michigan Herbarium, Ann Arbor, MI, USA
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Sun D, Herath J, Zhou S, Ellepola G, Meegaskumbura M. Associations of Batrachochytrium dendrobatidis with skin bacteria and fungi on Asian amphibian hosts. ISME COMMUNICATIONS 2023; 3:123. [PMID: 37993728 PMCID: PMC10665332 DOI: 10.1038/s43705-023-00332-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/24/2023]
Abstract
Amphibian skin harbors microorganisms that are associated with the fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes chytridiomycosis, one of the most significant wildlife diseases known. This pathogen originated in Asia, where diverse Bd lineages exist; hence, native amphibian hosts have co-existed with Bd over long time periods. Determining the nuances of this co-existence is crucial for understanding the prevalence and spread of Bd from a microbial context. However, associations of Bd with the natural skin microbiome remain poorly understood for Asian hosts, especially in relation to skin-associated fungi. We used 16 S rRNA and fungal internal transcribed spacer (ITS) gene sequencing to characterize the skin microbiome of four native Asian amphibian species and examined the relationships between Bd infection and their skin bacterial and fungal communities; we also analyzed the correlates of the putative anti-Bd bacteria. We show that both skin bacterial and fungal community structure and composition had significant associations with infection status (Bd presence/absence) and infection intensity (frequency of Bd sequence reads). We also found that the putative anti-Bd bacterial richness was correlated with Bd infection status and infection intensity, and observed that the relative abundance of anti-Bd bacteria roughly correspond with changes in both Bd prevalence and mean infection intensity in populations. Additionally, the microbial co-occurrence network of infected frogs was significantly different from that of uninfected frogs that were characterized by more keystone nodes (connectors) and larger proportions in correlations between bacteria, suggesting stronger inter-module bacterial interactions. These results indicate that the mutual effects between Bd and skin-associated microbiome, including the interplay between bacteria and fungi, might vary with Bd infection in susceptible amphibian species. This knowledge will help in understanding the dynamics of Bd from a microbial perspective, potentially contributing to mitigate chytridiomycosis in other regions of the world.
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Affiliation(s)
- Dan Sun
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
| | - Jayampathi Herath
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
- School of Biomedical Sciences, International Institute of Health Sciences (IIHS), No 704 Negombo Rd, Welisara, 71722, Sri Lanka
| | - Shipeng Zhou
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
| | - Gajaba Ellepola
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China
- Department of Zoology, Faculty of Science, University of Peradeniya, Peradeniya, KY20400, Sri Lanka
| | - Madhava Meegaskumbura
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China.
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Angoshtari R, Scribner KT, Marsh TL. The impact of primary colonizers on the community composition of river biofilm. PLoS One 2023; 18:e0288040. [PMID: 37956125 PMCID: PMC10642824 DOI: 10.1371/journal.pone.0288040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 06/19/2023] [Indexed: 11/15/2023] Open
Abstract
As a strategy for minimizing microbial infections in fish hatcheries, we have investigated how putatively probiotic bacterial populations influence biofilm formation. All surfaces that are exposed to the aquatic milieu develop a microbial community through the selective assembly of microbial populations into a surface-adhering biofilm. In the investigations reported herein, we describe laboratory experiments designed to determine how initial colonization of a surface by nonpathogenic isolates from sturgeon eggs influence the subsequent assembly of populations from a pelagic river community, into the existing biofilm. All eight of the tested strains altered the assembly of river biofilm in a strain-specific manner. Previously formed isolate biofilm was challenged with natural river populations and after 24 hours, two strains and two-isolate combinations proved highly resistant to invasion, comprising at least 80% of the biofilm community, four isolates were intermediate in resistance, accounting for at least 45% of the biofilm community and two isolates were reduced to 4% of the biofilm community. Founding biofilms of Serratia sp, and combinations of Brevundimonas sp.-Hydrogenophaga sp. and Brevundimonas sp.-Acidovorax sp. specifically blocked populations of Aeromonas and Flavobacterium, potential fish pathogens, from colonizing the biofilm. In addition, all isolate biofilms were effective at blocking invading populations of Arcobacter. Several strains, notably Deinococcus sp., recruited specific low-abundance river populations into the top 25 most abundant populations within biofilm. The experiments suggest that relatively simple measures can be used to control the assembly of biofilm on the eggs surface and perhaps offer protection from pathogens. In addition, the methodology provides a relatively rapid way to detect potentially strong ecological interactions between bacterial populations in the formation of biofilms.
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Affiliation(s)
- Roshan Angoshtari
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
| | - Kim T. Scribner
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, United States of America
| | - Terence L. Marsh
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States of America
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Vicente-Santos A, Willink B, Nowak K, Civitello DJ, Gillespie TR. Host-pathogen interactions under pressure: A review and meta-analysis of stress-mediated effects on disease dynamics. Ecol Lett 2023; 26:2003-2020. [PMID: 37804128 PMCID: PMC10874615 DOI: 10.1111/ele.14319] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/07/2023] [Accepted: 09/12/2023] [Indexed: 10/08/2023]
Abstract
Human activities have increased the intensity and frequency of natural stressors and created novel stressors, altering host-pathogen interactions and changing the risk of emerging infectious diseases. Despite the ubiquity of such anthropogenic impacts, predicting the directionality of outcomes has proven challenging. Here, we conduct a review and meta-analysis to determine the primary mechanisms through which stressors affect host-pathogen interactions and to evaluate the impacts stress has on host fitness (survival and fecundity) and pathogen infectivity (prevalence and intensity). We assessed 891 effect sizes from 71 host species (representing seven taxonomic groups) and 78 parasite taxa from 98 studies. We found that infected and uninfected hosts had similar sensitivity to stressors and that responses varied according to stressor type. Specifically, limited resources compromised host fecundity and decreased pathogen intensity, while abiotic environmental stressors (e.g., temperature and salinity) decreased host survivorship and increased pathogen intensity, and pollution increased mortality but decreased pathogen prevalence. We then used our meta-analysis results to develop susceptible-infected theoretical models to illustrate scenarios where infection rates are expected to increase or decrease in response to resource limitations or environmental stress gradients. Our results carry implications for conservation and disease emergence and reveal areas for future work.
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Affiliation(s)
- Amanda Vicente-Santos
- Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA 30322, USA
| | - Beatriz Willink
- Department of Zoology, Stockholm University, Stockholm 106-91, Sweden
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
- School of Biology, University of Costa Rica, San José 11501-2060, Costa Rica
| | - Kacy Nowak
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - David J. Civitello
- Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA 30322, USA
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Thomas R. Gillespie
- Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA 30322, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
- Department of Environmental Sciences, Emory University, Atlanta, GA 30322, USA
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Robak MJ, Saenz V, de Cortie E, Richards-Zawacki CL. Effects of temperature on the interaction between amphibian skin bacteria and Batrachochytrium dendrobatidis. Front Microbiol 2023; 14:1253482. [PMID: 37942072 PMCID: PMC10628663 DOI: 10.3389/fmicb.2023.1253482] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023] Open
Abstract
Symbiotic relationships between animals and microbes are important for a range of functions, from digestion to protection from pathogens. However, the impact of temperature variation on these animal-microbe interactions remains poorly understood. Amphibians have experienced population declines and even extinctions on a global scale due to chytridiomycosis, a disease caused by chytrid fungi in the genus Batrachochytrium. Variation in susceptibility to this disease exists within and among host species. While the mechanisms generating differences in host susceptibility remain elusive, differences in immune system components, as well as variation in host and environmental temperatures, have been associated with this variation. The symbiotic cutaneous bacteria of amphibians are another potential cause for variation in susceptibility to chytridiomycosis, with some bacterial species producing antifungal metabolites that prevent the growth of Bd. The growth of both Bd and bacteria are affected by temperature, and thus we hypothesized that amphibian skin bacteria may be more effective at preventing Bd growth at certain temperatures. To test this, we collected bacteria from the skins of frogs, harvested the metabolites they produced when grown at three different temperatures, and then grew Bd in the presence of those metabolites under those same three temperatures in a three-by-three fully crossed design. We found that both the temperature at which cutaneous bacteria were grown (and metabolites produced) as well as the temperature at which Bd is grown can impact the ability of cutaneous bacteria to inhibit the growth of Bd. While some bacterial isolates showed the ability to inhibit Bd growth across multiple temperature treatments, no isolate was found to be inhibitive across all combinations of bacterial incubation or Bd challenge temperatures, suggesting that temperature affects both the metabolites produced and the effectiveness of those metabolites against the Bd pathogen. These findings move us closer to a mechanistic understanding of why chytridiomycosis outbreaks and related amphibian declines are often limited to certain climates and seasons.
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Affiliation(s)
- Matthew J. Robak
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, United States
| | - Veronica Saenz
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Biology, The Pennsylvania State University, State College, PA, United States
| | - Esmee de Cortie
- Falk School of Sustainability and Environment, Chatham University, Pittsburgh, PA, United States
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Miller AJ, Gass J, Jo MC, Bishop L, Petereit J, Woodhams DC, Voyles J. Towards the generation of gnotobiotic larvae as a tool to investigate the influence of the microbiome on the development of the amphibian immune system. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220125. [PMID: 37305911 PMCID: PMC10258664 DOI: 10.1098/rstb.2022.0125] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/28/2022] [Indexed: 06/13/2023] Open
Abstract
The immune equilibrium model suggests that exposure to microbes during early life primes immune responses for pathogen exposure later in life. While recent studies using a range of gnotobiotic (germ-free) model organisms offer support for this theory, we currently lack a tractable model system for investigating the influence of the microbiome on immune system development. Here, we used an amphibian species (Xenopus laevis) to investigate the importance of the microbiome in larval development and susceptibility to infectious disease later in life. We found that experimental reductions of the microbiome during embryonic and larval stages effectively reduced microbial richness, diversity and altered community composition in tadpoles prior to metamorphosis. In addition, our antimicrobial treatments resulted in few negative effects on larval development, body condition, or survival to metamorphosis. However, contrary to our predictions, our antimicrobial treatments did not alter susceptibility to the lethal fungal pathogen Batrachochytrium dendrobatidis (Bd) in the adult life stage. While our treatments to reduce the microbiome during early development did not play a critical role in determining susceptibility to disease caused by Bd in X. laevis, they nevertheless indicate that developing a gnotobiotic amphibian model system may be highly useful for future immunological investigations. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
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Affiliation(s)
| | - Jordan Gass
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Myung Chul Jo
- Environmental Health and Safety, University of Nevada, Reno, NV 89557, USA
| | - Lucas Bishop
- Nevada Bioinformatics Center, University of Nevada, Reno, NV 89557, USA
| | - Juli Petereit
- Nevada Bioinformatics Center, University of Nevada, Reno, NV 89557, USA
| | | | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, NV 89557, USA
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Assis VR, Robert J, Titon SCM. Introduction to the special issue Amphibian immunity: stress, disease and ecoimmunology. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220117. [PMID: 37305915 PMCID: PMC10258669 DOI: 10.1098/rstb.2022.0117] [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: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Amphibian populations have been declining worldwide, with global climate changes and infectious diseases being among the primary causes of this scenario. Infectious diseases are among the primary drivers of amphibian declines, including ranavirosis and chytridiomycosis, which have gained more attention lately. While some amphibian populations are led to extinction, others are disease-resistant. Although the host's immune system plays a major role in disease resistance, little is known about the immune mechanisms underlying amphibian disease resistance and host-pathogen interactions. As ectotherms, amphibians are directly subjected to changes in temperature and rainfall, which modulate stress-related physiology, including immunity and pathogen physiology associated with diseases. In this sense, the contexts of stress, disease and ecoimmunology are essential for a better understanding of amphibian immunity. This issue brings details about the ontogeny of the amphibian immune system, including crucial aspects of innate and adaptive immunity and how ontogeny can influence amphibian disease resistance. In addition, the papers in the issue demonstrate an integrated view of the amphibian immune system associated with the influence of stress on immune-endocrine interactions. The collective body of research presented herein can provide valuable insights into the mechanisms underlying disease outcomes in natural populations, particularly in the context of changing environmental conditions. These findings may ultimately enhance our ability to forecast effective conservation strategies for amphibian populations. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
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Affiliation(s)
- Vania Regina Assis
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, 05508-900 São Paulo, Brazil
- College of Public Health, University of South Florida, Tampa, FL 33612-9415, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA
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10
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Hollanders M, Grogan LF, McCallum HI, Brannelly LA, Newell DA. Limited impact of chytridiomycosis on juvenile frogs in a recovered species. Oecologia 2023:10.1007/s00442-023-05406-w. [PMID: 37349661 DOI: 10.1007/s00442-023-05406-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 06/12/2023] [Indexed: 06/24/2023]
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused catastrophic frog declines on several continents, but disease outcome is mediated by a number of factors. Host life stage is an important consideration and many studies have highlighted the vulnerability of recently metamorphosed or juvenile frogs compared to adults. The majority of these studies have taken place in a laboratory setting, and there is a general paucity of longitudinal field studies investigating the influence of life stage on disease outcome. In this study, we assessed the effect of endemic Bd on juvenile Mixophyes fleayi (Fleay's barred frog) in subtropical eastern Australian rainforest. Using photographic mark-recapture, we made 386 captures of 116 individuals and investigated the effect of Bd infection intensity on the apparent mortality rates of frogs using a multievent model correcting for infection state misclassification. We found that neither Bd infection status nor infection intensity predicted mortality in juvenile frogs, counter to the expectation that early life stages are more vulnerable to disease, despite average high infection prevalence (0.35, 95% HDPI [0.14, 0.52]). Additionally, we found that observed infection prevalence and intensity were somewhat lower for juveniles than adults. Our results indicate that in this Bd-recovered species, the realized impacts of chytridiomycosis on juveniles were apparently low, likely resulting in high recruitment contributing to population stability. We highlight the importance of investigating factors relating to disease outcome in a field setting and make recommendations for future studies.
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Affiliation(s)
- Matthijs Hollanders
- Faculty of Science and Engineering, Southern Cross University, Lismore, NSW, Australia.
| | - Laura F Grogan
- Centre for Planetary Health and Food Security, and School of Environment and Science, Griffith University, Southport, QLD, Australia
| | - Hamish I McCallum
- Centre for Planetary Health and Food Security, and School of Environment and Science, Griffith University, Southport, QLD, Australia
| | - Laura A Brannelly
- Veterinary BioSciences, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, VIC, Australia
| | - David A Newell
- Faculty of Science and Engineering, Southern Cross University, Lismore, NSW, Australia
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Jacinto-Maldonado M, González-Salazar C, Basanta MD, García-Peña GE, Saucedo B, Lesbarrères D, Meza-Figueroa D, Stephens CR. Water Pollution Increases the Risk of Chytridiomycosis in Mexican Amphibians. ECOHEALTH 2023:10.1007/s10393-023-01631-0. [PMID: 37140741 DOI: 10.1007/s10393-023-01631-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 02/23/2023] [Accepted: 03/09/2023] [Indexed: 05/05/2023]
Abstract
Chytridiomycosis is affecting amphibians worldwide, causing the decline and extinction of several amphibian populations. The disease is caused by the fungus Batrachochytrium dendrobatidis (Bd), a multihost pathogen living in freshwater habitats. While several environmental factors have been associated with the prevalence of Bd and its virulence, the effects of water quality on the pathogen are not clear yet. Some evidence suggests that water pollution may reduce amphibians' immune response and increase prevalence of Bd. To explore this hypothesis, we analyzed the relationship between water quality and the presence of Bd by using spatial data mining of 150 geolocations of Bd in amphibians from 9 families where Bd positive specimens have been previously reported, and water quality in 4,202 lentic and lotic water bodies in Mexico from 2010 to 2021. Our model showed that in the 3 main families where Bd was recorded, its presence is high in locations with low water quality, i.e., water polluted likely contaminated with urban and industrial waste. Using this model, we inferred areas suitable for Bd in Mexico; mainly in poorly studied areas along the gulf and on the pacific slope. We further argue that actions to reduce water pollution should become an integral part of public policies to prevent the spread of Bd and protect amphibians from this deadly pathogen.
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Affiliation(s)
- M Jacinto-Maldonado
- Departamento de Geología, División de Ciencias Exactas y Naturales, Universidad de Sonora, Hermosillo Sonora, México.
- Centro de Ciencias de la Complejidad (C3), Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, México.
| | - C González-Salazar
- Centro de Ciencias de la Complejidad (C3), Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, México
- Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, México
| | - M D Basanta
- Department of Biology, University of Nevada Reno, Reno, NV, USA
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, Ciudad de Mexico, México
| | - G E García-Peña
- Centro de Ciencias de la Complejidad (C3), Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, México
| | - B Saucedo
- IDEXX Laboratories B.V, Holland, The Netherlands
| | - D Lesbarrères
- Environment and Climate Change Canada, Greater Sudbury, Canada
| | - D Meza-Figueroa
- Departamento de Geología, División de Ciencias Exactas y Naturales, Universidad de Sonora, Hermosillo Sonora, México
| | - C R Stephens
- Centro de Ciencias de la Complejidad (C3), Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, México
- Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México (UNAM), Av. Universidad 3000, Mexico City, México
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12
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Hardman RH, Reinert LK, Irwin KJ, Oziminski K, Rollins-Smith L, Miller DL. Disease state associated with chronic toe lesions in hellbenders may alter anti-chytrid skin defenses. Sci Rep 2023; 13:1982. [PMID: 36737574 PMCID: PMC9898527 DOI: 10.1038/s41598-023-28334-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Hellbenders (Cryptobranchus alleganiensis) are large, aquatic salamanders from the eastern United States. Both subspecies, eastern and Ozark hellbenders, have experienced declines resulting in federal listing of Ozark hellbenders. The globally distributed chytrid fungus, Batrachochytrium dendrobatidis (Bd) has been detected in both subspecies, and Batrachochytrium salamandrivorans (Bsal) poses a new threat if introduced into North America. Ozark hellbenders also suffer a high prevalence of toe lesions of unknown etiology, with changes in host immunocompetence hypothesized to contribute. Antimicrobial peptides (AMPs) secreted from dermal granular glands may play a role in hellbender health. We collected skin secretions from free-ranging hellbenders and enriched them for small cationic peptides used for growth inhibition assays against Bd and Bsal. Generalized linear mixed models revealed the presence of active toe lesions as the strongest and only significant predictor of decreased Bd inhibition by skin peptides. We also found skin secretions were more inhibitory of Bsal than Bd. MALDI-TOF mass spectrometry revealed candidate peptides responsible for anti-chytrid activity. Results support the hypothesis that hellbender skin secretions are important for innate immunity against chytrid pathogens, and decreased production or release of skin peptides may be linked to other sub-lethal effects of disease associated with toe lesions.
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Affiliation(s)
- Rebecca H Hardman
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA. .,Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, FL, 33701, USA.
| | - Laura K Reinert
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Kelly J Irwin
- Arkansas Game and Fish Commission, Benton, AR, 72015, USA
| | - Kendall Oziminski
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA
| | - Louise Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Debra L Miller
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA.,School of Natural of Resources, University of Tennessee, Knoxville, Tennessee, 37996, USA
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13
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Gomes FR, Madelaire CB, Moretti EH, Titon SCM, Assis VR. Immunoendocrinology and Ecoimmunology in Brazilian Anurans. Integr Comp Biol 2022; 62:1654-1670. [PMID: 35411921 DOI: 10.1093/icb/icac014] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
This paper reviews several aspects of immunoendocrinology and ecoimmunology in Brazilian species of anurans under investigation for more than a decade, including (1) patterns of annual covariation of circulating steroids, calling behavior and innate immunity, (2) endocrine and immune correlates of calling performance, (3) behavioral and physiological correlates of parasite load, (4) thermal sensitivity of immune function, and (5) endocrine and immunomodulation by experimental exposure to acute and chronic stressors, as well as to endocrine manipulations and simulated infections. Integrated results have shown an immunoprotective role of increased steroid plasma levels during reproductive activity in calling males. Moreover, a higher helminth parasite load is associated with changes in several behavioral and physiological traits under field conditions. We also found anuran innate immunity is generally characterized by eurythermy, with maximal performance observed in temperatures close to normal and fever thermal preferendum. Moreover, the aerobic scope of innate immune response is decreased at fever thermal preferendum. Experimental exposure to stressors results in increased corticosterone plasma levels and immune redistribution, with an impact on immune function depending on the duration of the stress exposure. Interestingly, the fate of immunomodulation by chronic stressors also depends in part on individual body condition. Acute treatment with corticosterone generally enhances immune function, while prolonged exposure results in immunosuppression. Still, the results of hormonal treatment are complex and depend on the dose, duration of treatment, and the immune variable considered. Finally, simulated infection results in complex modulation of the expression of cytokines, increased immune function, activation of the Hypothalamus-Pituitary-Interrenal axis, and decreased activity of the Hypothalamus-Pituitary-Gonadal axis, as well as reduced melatonin plasma levels, suggesting that anurans have a functional Immune-Pineal axis, homologous to that previously described for mammals. These integrated and complementary approaches have contributed to a better understanding of physiological mechanisms and processes, as well as ecological and evolutionary implications of anuran immunoendocrinology.
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Affiliation(s)
- Fernando Ribeiro Gomes
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, trav. 14, 101, São Paulo, SP 05508-090, Brasil
| | - Carla Bonetti Madelaire
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, trav. 14, 101, São Paulo, SP 05508-090, Brasil.,School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Eduardo Hermógenes Moretti
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Professor Lineu Prestes, 1730, São Paulo, SP 05508-900, Brasil
| | - Stefanny Christie Monteiro Titon
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, trav. 14, 101, São Paulo, SP 05508-090, Brasil
| | - Vania Regina Assis
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, trav. 14, 101, São Paulo, SP 05508-090, Brasil
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14
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Adams AJ, Bushell J, Grasso RL. To treat or not to treat? Experimental pathogen exposure, treatment, and release of a threatened amphibian. Ecosphere 2022. [DOI: 10.1002/ecs2.4294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Andrea J. Adams
- Resources Management and Science Division Yosemite National Park El Portal California USA
- Earth Research Institute University of California Santa Barbara California USA
| | | | - Robert L. Grasso
- Resources Management and Science Division Yosemite National Park El Portal California USA
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15
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Humphries JE, Lanctôt CM, Robert J, McCallum HI, Newell DA, Grogan LF. Do immune system changes at metamorphosis predict vulnerability to chytridiomycosis? An update. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 136:104510. [PMID: 35985564 DOI: 10.1016/j.dci.2022.104510] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/20/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Amphibians are among the vertebrate groups suffering great losses of biodiversity due to a variety of causes including diseases, such as chytridiomycosis (caused by the fungal pathogens Batrachochytrium dendrobatidis and B. salamandrivorans). The amphibian metamorphic period has been identified as being particularly vulnerable to chytridiomycosis, with dramatic physiological and immunological reorganisation likely contributing to this vulnerability. Here, we overview the processes behind these changes at metamorphosis and then perform a systematic literature review to capture the breadth of empirical research performed over the last two decades on the metamorphic immune response. We found that few studies focused specifically on the immune response during the peri-metamorphic stages of amphibian development and fewer still on the implications of their findings with respect to chytridiomycosis. We recommend future studies consider components of the immune system that are currently under-represented in the literature on amphibian metamorphosis, particularly pathogen recognition pathways. Although logistically challenging, we suggest varying the timing of exposure to Bd across metamorphosis to examine the relative importance of pathogen evasion, suppression or dysregulation of the immune system. We also suggest elucidating the underlying mechanisms of the increased susceptibility to chytridiomycosis at metamorphosis and the associated implications for population persistence. For species that overlap a distribution where Bd/Bsal are now endemic, we recommend a greater focus on management strategies that consider the important peri-metamorphic period.
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Affiliation(s)
- Josephine E Humphries
- School of Environment and Science, Griffith University, Southport, Queensland, 4222, Australia; Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland, 4222, Australia; Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, 2480, Australia.
| | - Chantal M Lanctôt
- School of Environment and Science, Griffith University, Southport, Queensland, 4222, Australia; Australian Rivers Institute, Griffith University, Southport, Queensland, 4222, Australia
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, 14642, Rochester, NY, United States
| | - Hamish I McCallum
- School of Environment and Science, Griffith University, Southport, Queensland, 4222, Australia; Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland, 4222, Australia
| | - David A Newell
- Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, 2480, Australia
| | - Laura F Grogan
- School of Environment and Science, Griffith University, Southport, Queensland, 4222, Australia; Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland, 4222, Australia
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16
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Demori I, El Rashed Z, De Negri Atanasio G, Parodi A, Millo E, Salis A, Costa A, Rosa G, Zanotti Russo M, Salvidio S, Cortese K, Grasselli E. First Evidence of Anti-Steatotic Action of Macrotympanain A1, an Amphibian Skin Peptide from Odorrana macrotympana. Molecules 2022; 27:7417. [PMID: 36364243 PMCID: PMC9656375 DOI: 10.3390/molecules27217417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/10/2022] [Accepted: 10/27/2022] [Indexed: 11/26/2023] Open
Abstract
Many different amphibian skin peptides have been characterized and proven to exert various biological actions, such as wound-healing, immunomodulatory, anti-oxidant, anti-inflammatory and anti-diabetic effects. In this work, the possible anti-steatotic effect of macrotympanain A1 (MA1) (FLPGLECVW), a skin peptide isolated from the Chinese odorous frog Odorrana macrotympana, was investigated. We used a well-established in vitro model of hepatic steatosis, consisting of lipid-loaded rat hepatoma FaO cells. In this model, a 24 h treatment with 10 µg/mL MA1 exerted a significant anti-steatotic action, being able to reduce intracellular triglyceride content. Accordingly, the number and diameter of cytosolic lipid droplets (LDs) were reduced by peptide treatment. The expression of key genes of hepatic lipid metabolism, such as PPARs and PLINs, was measured by real-time qPCR. MA1 counteracted the fatty acid-induced upregulation of PPARγ expression and increased PLIN3 expression, suggesting a role in promoting lipophagy. The present data demonstrate for the first time a direct anti-steatotic effect of a peptide from amphibian skin secretion and pave the way to further studies on the use of amphibian peptides for beneficial actions against metabolic diseases.
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Affiliation(s)
- Ilaria Demori
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Pisa, Italy
| | - Zeinab El Rashed
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy
| | - Giulia De Negri Atanasio
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy
| | - Alice Parodi
- Department of Experimental Medicine (DIMES), Section of Biochemistry, University of Genoa, Viale Benedetto XV 1, 16132 Genoa, Italy
| | - Enrico Millo
- Department of Experimental Medicine (DIMES), Section of Biochemistry, University of Genoa, Viale Benedetto XV 1, 16132 Genoa, Italy
| | - Annalisa Salis
- Department of Experimental Medicine (DIMES), Section of Biochemistry, University of Genoa, Viale Benedetto XV 1, 16132 Genoa, Italy
| | - Andrea Costa
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy
| | - Giacomo Rosa
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy
| | | | - Sebastiano Salvidio
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy
| | - Katia Cortese
- Department of Experimental Medicine (DIMES), Cellular Electron Microscopy Laboratory, University of Genoa, Via Antonio de Toni 14, 16132 Genoa, Italy
| | - Elena Grasselli
- Department of Earth, Environmental, and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Pisa, Italy
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17
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Urbanization impacts parasite diversity in the cane toad Rhinella horribilis (Anura: Bufonidae). Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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18
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Basanta MD, Anaya‐Morales SL, Martínez‐Ugalde E, González Martínez TM, Ávila‐Akerberg VD, Trejo MV, Rebollar EA. Metamorphosis and seasonality are major determinants of chytrid infection in a paedomorphic salamander. Anim Conserv 2022. [DOI: 10.1111/acv.12824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. D. Basanta
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
- Department of Biology University of Nevada Reno Reno NV USA
| | - S. L. Anaya‐Morales
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
| | - E. Martínez‐Ugalde
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
| | - T. M. González Martínez
- Facultad de Ciencias Universidad Nacional Autónoma de México, Ciudad Universitaria Ciudad de México Mexico
| | - V. D. Ávila‐Akerberg
- Instituto de Ciencias Agropecuarias y Rurales Universidad Autónoma del Estado de México Toluca Estado de México Mexico
| | - M. V. Trejo
- Facultad de Ciencias Universidad Nacional Autónoma de México, Ciudad Universitaria Ciudad de México Mexico
| | - E. A. Rebollar
- Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos Mexico
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19
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Cook K, Pope K, Cummings A, Piovia‐Scott J. In situ treatment of juvenile frogs for disease can reverse population declines. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Kimberly Cook
- School of Biological Sciences Washington State University Vancouver WA USA
| | - Karen Pope
- Pacific Southwest Research Station United States Forest Service California USA
| | - Adam Cummings
- Pacific Southwest Research Station United States Forest Service California USA
| | - Jonah Piovia‐Scott
- School of Biological Sciences Washington State University Vancouver WA USA
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20
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Liu Y, Huang M, Wang Y, Duan R, Guo J, Cao X, Xu X. Short-term continuous and pulse Pb exposure causes negative effects on skin histomorphological structure and bacterial composition of adult Pelophylax nigromaculatus. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:56592-56605. [PMID: 35338466 DOI: 10.1007/s11356-022-19743-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
Lead (Pb) is a toxic heavy metal often present in the environment as a pulse in water. Traditional toxicity tests are usually carried out under conditions of continuous concentration, without considering the impact of pulse exposure on aquatic organisms. This study aimed to evaluate the effects of short-term continuous and pulse Pb exposures on the skin bacteria and histomorphological structure of Pelophylax nigromaculatus. Results showed that compared to the control (CON) and Pb continuous exposure group (CEPb), the Pb pulse exposure group (PEPb) showed the smallest size of granular glands, which would interfere with the permeability and secretory function of skin, making the individual more sensitive to external pollution. Lead exposure significantly changed the composition and diversity of skin bacteria. Compared to the CON and CEPb groups, the PEPb group showed a significant increase in the abundance of harmful bacteria (e.g., Bacteroidetes and Chryseobacterium) and a decrease in the abundance of beneficial bacteria (e.g., Pseudomonas). PICRUSt software showed that there were differences in the metabolic pathway of skin bacteria among the three groups (CON, CEPb, and PEPb). Overall, this study indicates that Pb pulse exposure can aggravate the toxicity of Pb for frog skin, providing a new framework for simulating short-term heavy metal exposure in the context of frog health.
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Affiliation(s)
- Yang Liu
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Minyi Huang
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China.
| | - Yujiao Wang
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Renyan Duan
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Jun Guo
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Xiaohong Cao
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Xiang Xu
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
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21
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Rosa GM, Perez R, Richards LA, Richards‐Zawacki CL, Smilanich AM, Reinert LK, Rollins‐Smith LA, Wetzel DP, Voyles J. Seasonality of host immunity in a tropical disease system. Ecosphere 2022. [DOI: 10.1002/ecs2.4158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Gonçalo M. Rosa
- Department of Biology University of Nevada, Reno Reno Nevada USA
- Institute of Zoology Zoological Society of London London UK
- Centre for Ecology, Evolution and Environmental Changes Faculdade de Ciências da Universidade de Lisboa Lisbon Portugal
| | - Rachel Perez
- Department of Biology New Mexico Institute of Mining and Technology Socorro New Mexico USA
| | - Lora A. Richards
- Department of Biology University of Nevada, Reno Reno Nevada USA
| | | | | | - Laura K. Reinert
- Department of Pathology Microbiology and Immunology, Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Louise A. Rollins‐Smith
- Department of Pathology Microbiology and Immunology, Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Daniel P. Wetzel
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Jamie Voyles
- Department of Biology University of Nevada, Reno Reno Nevada USA
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22
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Martins RA, Greenspan SE, Medina D, Buttimer S, Marshall VM, Neely WJ, Siomko S, Lyra ML, Haddad CFB, São-Pedro V, Becker CG. Signatures of functional bacteriome structure in a tropical direct-developing amphibian species. Anim Microbiome 2022; 4:40. [PMID: 35672870 PMCID: PMC9172097 DOI: 10.1186/s42523-022-00188-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 05/17/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Host microbiomes may differ under the same environmental conditions and these differences may influence susceptibility to infection. Amphibians are ideal for comparing microbiomes in the context of disease defense because hundreds of species face infection with the skin-invading microbe Batrachochytrium dendrobatidis (Bd), and species richness of host communities, including their skin bacteria (bacteriome), may be exceptionally high. We conducted a landscape-scale Bd survey of six co-occurring amphibian species in Brazil’s Atlantic Forest. To test the bacteriome as a driver of differential Bd prevalence, we compared bacteriome composition and co-occurrence network structure among the six focal host species.
Results
Intensive sampling yielded divergent Bd prevalence in two ecologically similar terrestrial-breeding species, a group with historically low Bd resistance. Specifically, we detected the highest Bd prevalence in Ischnocnema henselii but no Bd detections in Haddadus binotatus. Haddadus binotatus carried the highest bacteriome alpha and common core diversity, and a modular network partitioned by negative co-occurrences, characteristics associated with community stability and competitive interactions that could inhibit Bd colonization.
Conclusions
Our findings suggest that community structure of the bacteriome might drive Bd resistance in H. binotatus, which could guide microbiome manipulation as a conservation strategy to protect diverse radiations of direct-developing species from Bd-induced population collapses.
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23
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Gass J, Voyles J. When Defenses Fail: Atelopus zeteki Skin Secretions Increase Growth of the Pathogen Batrachochytrium dendrobatidis. Integr Comp Biol 2022; 62:1595-1605. [PMID: 35640912 PMCID: PMC9801971 DOI: 10.1093/icb/icac060] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/30/2022] [Accepted: 05/24/2022] [Indexed: 01/05/2023] Open
Abstract
To combat the threat of emerging infectious diseases in wildlife, ecoimmunologists seek to understand the complex interactions among pathogens, their hosts, and their shared environments. The cutaneous fungal pathogen Batrachochytrium dendrobatidis (Bd), has led to the decline of innumerable amphibian species, including the Panamanian golden frog (Atelopus zeteki). Given that Bd can evade or dampen the acquired immune responses of some amphibians, nonspecific immune defenses are thought to be especially important for amphibian defenses against Bd. In particular, skin secretions constitute a vital component of amphibian innate immunity against skin infections, but their role in protecting A. zeteki from Bd is unknown. We investigated the importance of this innate immune component by reducing the skin secretions from A. zeteki and evaluating their effectiveness against Bd in vitro and in vivo. Following exposure to Bd in a controlled inoculation experiment, we compared key disease characteristics (e.g., changes in body condition, prevalence, pathogen loads, and survival) among groups of frogs that had their skin secretions reduced and control frogs that maintained their skin secretions. Surprisingly, we found that the skin secretions collected from A. zeteki increased Bd growth in vitro. This finding was further supported by infection and survival patterns in the in vivo experiment where frogs with reduced skin secretions tended to have lower pathogen loads and survive longer compared to frogs that maintained their secretions. These results suggest that the skin secretions of A. zeteki are not only ineffective at inhibiting Bd but may enhance Bd growth, possibly leading to greater severity of disease and higher mortality in this highly vulnerable species. These results differ from those of previous studies in other amphibian host species that suggest that skin secretions are a key defense in protecting amphibians from developing severe chytridiomycosis. Therefore, we suggest that the importance of immune components cannot be generalized across all amphibian species or over time. Moreover, the finding that skin secretions may be enhancing Bd growth emphasizes the importance of investigating these immune components in detail, especially for species that are a conservation priority.
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Affiliation(s)
- Jordan Gass
- Department of Biology, University of Nevada at Reno, 1664 North Virginia Street, Reno, NV 89557, USA
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Inhibitory Bacterial Diversity and Mucosome Function Differentiate Susceptibility of Appalachian Salamanders to Chytrid Fungal Infection. Appl Environ Microbiol 2022; 88:e0181821. [PMID: 35348389 PMCID: PMC9040618 DOI: 10.1128/aem.01818-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Mucosal defenses are crucial in animals for protection against pathogens and predators. Host defense peptides (antimicrobial peptides, AMPs) as well as skin-associated microbes are key components of mucosal immunity, particularly in amphibians. We integrate microbiology, molecular biology, network-thinking, and proteomics to understand how host and microbially derived products on amphibian skin (referred to as the mucosome) serve as pathogen defenses. We studied defense mechanisms against chytrid pathogens, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), in four salamander species with different Batrachochytrium susceptibilities. Bd infection was quantified using qPCR, mucosome function (i.e., ability to kill Bd or Bsal zoospores in vitro), skin bacterial communities using 16S rRNA gene amplicon sequencing, and the role of Bd-inhibitory bacteria in microbial networks across all species. We explored the presence of candidate-AMPs in eastern newts and red-backed salamanders. Eastern newts had the highest Bd prevalence and mucosome function, while red-back salamanders had the lowest Bd prevalence and mucosome function, and two-lined salamanders and seal salamanders were intermediates. Salamanders with highest Bd infection intensity showed greater mucosome function. Bd infection prevalence significantly decreased as putative Bd-inhibitory bacterial richness and relative abundance increased on hosts. In co-occurrence networks, some putative Bd-inhibitory bacteria were found as hub-taxa, with red-backs having the highest proportion of protective hubs and positive associations related to putative Bd-inhibitory hub bacteria. We found more AMP candidates on salamanders with lower Bd susceptibility. These findings suggest that salamanders possess distinct innate mechanisms that affect chytrid fungi. IMPORTANCE How host mucosal defenses interact, and influence disease outcome is critical in understanding host defenses against pathogens. A more detailed understanding is needed of the interactions between the host and the functioning of its mucosal defenses in pathogen defense. This study investigates the variability of chytrid susceptibility in salamanders and the innate defenses each species possesses to mediate pathogens, thus advancing the knowledge toward a deeper understanding of the microbial ecology of skin-associated bacteria and contributing to the development of bioaugmentation strategies to mediate pathogen infection and disease. This study improves the understanding of complex immune defense mechanisms in salamanders and highlights the potential role of the mucosome to reduce the probability of Bd disease development and that putative protective bacteria may reduce likelihood of Bd infecting skin.
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Haver M, Le Roux G, Friesen J, Loyau A, Vredenburg VT, Schmeller DS. The role of abiotic variables in an emerging global amphibian fungal disease in mountains. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 815:152735. [PMID: 34974000 DOI: 10.1016/j.scitotenv.2021.152735] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/23/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
The emergence of the chytridiomycete fungal pathogen Batrachochytrium dendrobatidis (Bd), causing the disease chytridiomycosis, has caused collapse of amphibian communities in numerous mountain systems. The health of amphibians and of mountain freshwater habitats they inhabit is also threatened by ongoing changes in environmental and anthropogenic factors such as climate, hydrology, and pollution. Climate change is causing more extreme climatic events, shifts in ice occurrence, and changes in the timing of snowmelt and pollutant deposition cycles. All of these factors impact both pathogen and host, and disease dynamics. Here we review abiotic variables, known to control Bd occurrence and chytridiomycosis severity, and discuss how climate change may modify them. We propose two main categories of abiotic variables that may alter Bd distribution, persistence, and physiology: 1) climate and hydrology (temperature, precipitation, hydrology, ultraviolet radiation (UVR); and, 2) water chemistry (pH, salinity, pollution). For both categories, we identify topics for further research. More studies on the relationship between global change, pollution and pathogens in complex landscapes, such as mountains, are needed to allow for accurate risk assessments for freshwater ecosystems and resulting impacts on wildlife and human health. Our review emphasizes the importance of using data of higher spatiotemporal resolution and uniform abiotic metrics in order to better compare study outcomes. Fine-scale temperature variability, especially of water temperature, variability of moisture conditions and water levels, snow, ice and runoff dynamics should be assessed as abiotic variables shaping the mountain habitat of pathogen and host. A better understanding of hydroclimate and water chemistry variables, as co-factors in disease, will increase our understanding of chytridiomycosis dynamics.
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Affiliation(s)
- Marilen Haver
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France.
| | - Gaël Le Roux
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France
| | - Jan Friesen
- Environmental and Biotechnology Centre, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Adeline Loyau
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France; Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, Stechlin D-16775, Germany
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - Dirk S Schmeller
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France
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Akat E, Yenmiş M, Pombal MA, Molist P, Megías M, Arman S, Veselỳ M, Anderson R, Ayaz D. Comparison of Vertebrate Skin Structure at Class Level: A Review. Anat Rec (Hoboken) 2022; 305:3543-3608. [DOI: 10.1002/ar.24908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/14/2022] [Accepted: 02/21/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Esra Akat
- Ege University, Faculty of Science, Biology Department Bornova, İzmir Turkey
| | - Melodi Yenmiş
- Ege University, Faculty of Science, Biology Department Bornova, İzmir Turkey
| | - Manuel A. Pombal
- Universidade de Vigo, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía‐IBIV Vigo, España
| | - Pilar Molist
- Universidade de Vigo, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía‐IBIV Vigo, España
| | - Manuel Megías
- Universidade de Vigo, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía‐IBIV Vigo, España
| | - Sezgi Arman
- Sakarya University, Faculty of Science and Letters, Biology Department Sakarya Turkey
| | - Milan Veselỳ
- Palacky University, Faculty of Science, Department of Zoology Olomouc Czechia
| | - Rodolfo Anderson
- Departamento de Zoologia, Instituto de Biociências Universidade Estadual Paulista São Paulo Brazil
| | - Dinçer Ayaz
- Ege University, Faculty of Science, Biology Department Bornova, İzmir Turkey
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Niu Y, Chen Q, Storey KB, Teng L, Li X, Xu T, Zhang H. Physiological ecology of winter hibernation by the high-altitude frog, Nanorana parkeri. Physiol Biochem Zool 2022; 95:201-211. [DOI: 10.1086/718764] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Haddad CF, Lopes CM, Becker CG, da Silva FR, Lyra ML. From genes to ecosystems: a synthesis of amphibian biodiversity research in Brazil. BIOTA NEOTROPICA 2022. [DOI: 10.1590/1676-0611-bn-2022-1375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract Here, we summarize examples of significant advances in amphibian research supported by the São Paulo Research Foundation (FAPESP), focusing on recent discoveries in the fields of community ecology, habitat change, infection diseases, and multipurpose DNA sequencing. We demonstrated that FAPESP has been fundamental not only by directly funding research projects and scholarships, but also through its science training policy, fostering international collaborations with world-class research institutions, improving and consolidating new lines of research that often depended on a synergetic combination of different knowledge and complex tools. We emphasized that future studies will continue to focus on basic questions, such as description of new species, as well as taxonomic and systematic corrections. Furthermore, we also expect that there will be a strong integration among different disciplines using novel bioinformatics tools and modeling approaches, such as machine learning. These new approaches will be critical to further develop our understanding of foundational questions of amphibian life-history trait variation, disease transmission, community assembly, biogeography, and population forecasts under different global change scenarios such as agricultural expansion, agrochemical use, habitat loss, and climate change.
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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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Eskew EA, Fraser D, Vonhof MJ, Pinsky ML, Maslo B. Host gene expression in wildlife disease: making sense of species-level responses. Mol Ecol 2021; 30:6517-6530. [PMID: 34516689 DOI: 10.1111/mec.16172] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 08/16/2021] [Accepted: 08/31/2021] [Indexed: 12/11/2022]
Abstract
Emerging infectious diseases are significant threats to wildlife conservation, yet the impacts of pathogen exposure and infection can vary widely among host species. As such, conservation biologists and disease ecologists have increasingly aimed to understand species-specific host susceptibility using molecular methods. In particular, comparative gene expression assays have been used to contrast the transcriptomic responses of disease-resistant and disease-susceptible hosts to pathogen exposure. This work usually assumes that the gene expression responses of disease-resistant species will reveal the activation of molecular pathways contributing to host defence. However, results often show that disease-resistant hosts undergo little gene expression change following pathogen challenge. Here, we discuss the mechanistic implications of these "null" findings and offer methodological suggestions for future molecular studies of wildlife disease. First, we highlight that muted transcriptomic responses with minimal immune system recruitment may indeed be protective for nonsusceptible hosts if they limit immunopathology and promote pathogen tolerance in systems where susceptible hosts suffer from genetic dysregulation. Second, we argue that overly narrow investigation of responses to pathogen exposure may overlook important, constitutively active molecular pathways that underlie species-specific defences. Finally, we outline alternative study designs and approaches that complement interspecific transcriptomic comparisons, including intraspecific gene expression studies and genomic methods to detect signatures of selection. Collectively, these insights will help ecologists extract maximal information from conservation-relevant transcriptomic data sets, leading to a deeper understanding of host defences and, ultimately, the implementation of successful conservation interventions.
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Affiliation(s)
- Evan A Eskew
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Department of Biology, Pacific Lutheran University, Tacoma, Washington, USA
| | - Devaughn Fraser
- Wildlife Genetics Research Laboratory, California Department of Fish and Wildlife, Sacramento, California, USA
| | - Maarten J Vonhof
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan, USA
| | - Malin L Pinsky
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Brooke Maslo
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
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Fisher MC, Pasmans F, Martel A. Virulence and Pathogenicity of Chytrid Fungi Causing Amphibian Extinctions. Annu Rev Microbiol 2021; 75:673-693. [PMID: 34351790 DOI: 10.1146/annurev-micro-052621-124212] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ancient enzootic associations between wildlife and their infections allow evolution to innovate mechanisms of pathogenicity that are counterbalanced by host responses. However, erosion of barriers to pathogen dispersal by globalization leads to the infection of hosts that have not evolved effective resistance and the emergence of highly virulent infections. Global amphibian declines driven by the rise of chytrid fungi and chytridiomycosis are emblematic of emerging infections. Here, we review how modern biological methods have been used to understand the adaptations and counteradaptations that these fungi and their amphibian hosts have evolved. We explore the interplay of biotic and abiotic factors that modify the virulence of these infections and dissect the complexity of this disease system. We highlight progress that has led to insights into how we might in the future lessen the impact of these emerging infections. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial School of Public Health, Imperial College London, London W2 1PG, United Kingdom;
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
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32
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Barnes EM, Kutos S, Naghshineh N, Mesko M, You Q, Lewis JD. Assembly of the amphibian microbiome is influenced by the effects of land-use change on environmental reservoirs. Environ Microbiol 2021; 23:4595-4611. [PMID: 34190389 DOI: 10.1111/1462-2920.15653] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/15/2021] [Accepted: 06/28/2021] [Indexed: 01/04/2023]
Abstract
A growing focus in microbial ecology is understanding how beneficial microbiome function is created and maintained through various assembly mechanisms. This study explores the role of both the environment and disease in regulating the composition of microbial species in the soil and on amphibian hosts. We compared the microbial communities of Plethodon cinereus salamanders along a land-use gradient in the New York metropolitan area and paired these with associated soil cores. Additionally, we characterized the diversity of bacterial and fungal symbionts that putatively inhibit the pathogenic fungus Batrachochytrium dendrobatidis. We predicted that variation in skin microbial community composition would correlate with changes seen in the soil which functions as the regional species pool. We found that salamanders and soil share many microbial taxa but that these two communities exhibit differences in the relative abundances of the bacterial phyla Acidobacteria, Actinobacteria, and Proteobacteria and the fungal phyla Ascomycota and genus Basidiobolus. Microbial community composition varies with changes in land-use associated factors creating site-specific compositions. By employing a quantitative, null-based assembly model, we identified that dispersal limitation, variable selection, and drift guide assembly of microbes onto their skin, creating high dissimilarity between individuals with likely consequences in disease preventative function.
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Affiliation(s)
- Elle M Barnes
- Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, 10504, USA.,Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA
| | - Steve Kutos
- Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, 10504, USA.,Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA
| | - Nina Naghshineh
- Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, 10504, USA.,Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA
| | - Marissa Mesko
- Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA
| | - Qing You
- Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA
| | - J D Lewis
- Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, 10504, USA.,Department of Biological Sciences, Fordham University, Bronx, NY, 10458, USA
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Ujszegi J, Ludányi K, Móricz ÁM, Krüzselyi D, Drahos L, Drexler T, Németh MZ, Vörös J, Garner TWJ, Hettyey A. Exposure to Batrachochytrium dendrobatidis affects chemical defences in two anuran amphibians, Rana dalmatina and Bufo bufo. BMC Ecol Evol 2021; 21:135. [PMID: 34217227 PMCID: PMC8254444 DOI: 10.1186/s12862-021-01867-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 06/23/2021] [Indexed: 11/03/2022] Open
Abstract
Background Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis, one of the major causes of worldwide amphibian biodiversity loss. Many amphibians exhibit skin-based chemical defences, which may play an important role against invading pathogens, but whether the synthesis of these chemical compounds is enhanced or suppressed in the presence of pathogens is largely unknown. Here we investigated direct and indirect effects of larval exposure to the globally distributed and highly virulent Bd-GPL strain on skin secreted chemical defences and life history traits during early ontogeny of agile frogs (Rana dalmatina) and common toads (Bufo bufo). Results Exposure to Bd during the larval stage did not result in enhanced synthesis of the antimicrobial peptide Brevinin-1 Da in R. dalmatina tadpoles or in increased production of bufadienolides in B. bufo tadpoles. However, exposure to Bd during the larval stage had a carry-over effect reaching beyond metamorphosis: both R. dalmatina and B. bufo froglets contained smaller quantities of defensive chemicals than their Bd-naïve conspecifics in the control treatment. Prevalence of Bd and infection intensities were very low in both larvae and metamorphs of R. dalmatina, while in B. bufo we observed high Bd prevalence and infection intensities, especially in metamorphs. At the same time, we did not find a significant effect of Bd-exposure on body mass or development rate in larvae or metamorphs in either species. Conclusions The lack of detrimental effect of Bd-exposure on life history traits, even parallel with high infection intensities in the case of B. bufo individuals, is surprising and suggests high tolerance of local populations of these two species against Bd. However, the lowered quantity of defensive chemicals may compromise antimicrobial and antipredatory defences of froglets, which may ultimately contribute to population declines also in the absence of conspicuous mass-mortality events.
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Affiliation(s)
- János Ujszegi
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, Budapest, 1022, Hungary.
| | - Krisztina Ludányi
- Department of Pharmaceutics, Faculty of Pharmacy, Semmelweis University, Hőgyes Endre utca 7, Budapest, 1092, Hungary
| | - Ágnes M Móricz
- Department of Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, Budapest, 1022, Hungary
| | - Dániel Krüzselyi
- Department of Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, Budapest, 1022, Hungary
| | - László Drahos
- MS Proteomics Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, Budapest, 1117, Hungary
| | - Tamás Drexler
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, Budapest, 1022, Hungary.,Department of Ecology, Institute for Biology, University of Veterinary Medicine, Rottenbiller utca 50, Budapest, 1077, Hungary
| | - Márk Z Németh
- Department of Plant Pathology, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, Budapest, 1022, Hungary
| | - Judit Vörös
- Department of Zoology, Hungarian Natural History Museum, Baross street 13, Budapest, 1088, Hungary
| | - Trenton W J Garner
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.,Unit for Environmental Sciences and Management, North-West University, Potchefstroom, 2520, South Africa
| | - Attila Hettyey
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, Budapest, 1022, Hungary.,Department of Ecology, Institute for Biology, University of Veterinary Medicine, Rottenbiller utca 50, Budapest, 1077, Hungary
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HIGHER INFECTION PREVALENCE IN AMPHIBIANS INHABITING HUMAN-MADE COMPARED TO NATURAL WETLANDS. J Wildl Dis 2021; 56:823-836. [PMID: 33600598 DOI: 10.7589/2019-09-220] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 02/21/2020] [Indexed: 11/20/2022]
Abstract
It is unclear how suitable human-made wetlands are for supporting wildlife and how they impact wildlife disease risk. Natural wetlands (those that were created without human actions) can support more diverse and resilient communities that are at lower risk of disease outbreaks. We compared frog community composition and infection with the pathogenic fungus Batrachochytrium dendrobatidis (Bd) between human-made and natural wetlands in Tippecanoe County, Indiana, US. We conducted visual encounter surveys of frog communities and quantified Bd infection prevalence at four natural and five human-made wetlands. Water parameters associated with human practices (e.g., pH, salinity) and surrounding land use were also compared across sites. We found higher Bd infection prevalence at human-made sites than at natural sites, with monthly differences showing highest infection in spring and fall, and decreasing infection with increasing water temperature. However, we found no differences between human-made and natural sites regarding amphibian community composition, water quality, or surrounding land use. Further, we found frog density increased with distance to nearest roads among both human-made and natural sites. These findings might suggest that human-made wetlands can support frog communities similar to natural wetlands, but pose a greater risk of Bd infection.
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Medina D, Greenspan SE, Carvalho T, Becker CG, Toledo LF. Co-infecting pathogen lineages have additive effects on host bacterial communities. FEMS Microbiol Ecol 2021; 97:6134751. [PMID: 33580951 DOI: 10.1093/femsec/fiab030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 02/11/2021] [Indexed: 01/08/2023] Open
Abstract
Amphibian skin bacteria may confer protection against the fungus Batrachochytrium dendrobatidis (Bd), but responses of skin bacteria to different Bd lineages are poorly understood. The global panzootic lineage (Bd-GPL) has caused amphibian declines and extinctions globally. However, other lineages are enzootic (Bd-Asia-2/Brazil). Increased contact rates between Bd-GPL and enzootic lineages via globalization pose unknown consequences for host-microbiome-pathogen dynamics. We conducted a laboratory experiment and used 16S rRNA amplicon-sequencing to assess: (i) whether two lineages (Bd-Asia-2/Brazil and Bd-GPL) and their recombinant, in single and mixed infections, differentially affect amphibian skin bacteria; (ii) and the changes associated with the transition to laboratory conditions. We determined no clear differences in bacterial diversity among Bd treatments, despite differences in infection intensity. However, we observed an additive effect of mixed infections on bacterial alpha diversity and a potentially antagonistic interaction between Bd genotypes. Additionally, observed changes in community composition suggest a higher ability of Bd-GPL to alter skin bacteria. Lastly, we observed a drastic reduction in bacterial diversity and a change in community structure in laboratory conditions. We provide evidence for complex interactions between Bd genotypes and amphibian skin bacteria during coinfections, and expand on the implications of experimental conditions in ecological studies.
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Affiliation(s)
- Daniel Medina
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas, R. Monteiro Lobato, 255 - CEP 13083-862, Campinas, São Paulo, Brazil.,Sistema Nacional de Investigación, SENACYT, Building 205, City of Knowledge, Clayton, Panama, Republic of Panama
| | - Sasha E Greenspan
- Department of Biological Sciences, The University of Alabama, 1339 Science and Engineering Complex, Tuscaloosa 35487, Alabama, USA
| | - Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas, R. Monteiro Lobato, 255 - CEP 13083-862, Campinas, São Paulo, Brazil
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, 1339 Science and Engineering Complex, Tuscaloosa 35487, Alabama, USA
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Instituto de Biologia, Universidade Estadual de Campinas, R. Monteiro Lobato, 255 - CEP 13083-862, Campinas, São Paulo, Brazil
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Mariano DO, Sciani JM, Antoniazzi MM, Jared C, Conceição K, Pimenta DC. Quantity - but not diversity - of secreted peptides and proteins increases with age in the tree frog Pithecopus nordestinus. J Venom Anim Toxins Incl Trop Dis 2021; 27:e20200105. [PMID: 33868394 PMCID: PMC8020714 DOI: 10.1590/1678-9199-jvatitd-2020-0105] [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] [Indexed: 11/21/2022] Open
Abstract
Background: Amphibians inhabit the terrestrial environment, a conquest achieved after several evolutionary steps, which were still insufficient to make them completely independent of the aquatic environment. These processes gave rise to many morphological and physiological changes, making their skin (and cutaneous secretion) rich in bioactive molecules. Among the tree frogs, the secretion is composed mainly of peptides; but alkaloids, proteins and steroids can also be found depending on the species. The most known class of biologically active molecules is the antimicrobial peptides (AMPs) that act against bacteria, fungi and protozoans. Although these molecules are well-studied among the hylids, AMPs ontogeny remains unknown. Therefore, we performed peptidomic and proteomic analyses of Pithecopus nordestinus (formerly Phyllomedusa nordestina) in order to evaluate the peptide content in post-metamorphosed juveniles and adult individuals. Methods: Cutaneous secretion of both life stages of individuals was obtained and analyzed by LC-MS/MS after reduction and alkylation of disulfide bonds or reduction, alkylation and hydrolysis by trypsin. Results: Differences in the TIC profile of juveniles and adults in both treatments were observed. Moreover, the proteomic data revealed known proteins and peptides, with slight differences in the composition, according to the life stage and the treatment. AMPs were identified, and bradykinin-potentiating peptides were observed in trypsin-treated samples, which suggests a protein source of such peptide (cryptide). Conclusion: In general, skin secretion contents were similar between juveniles and adults, varying in quantity, indicating that the different stages of life are reflected in the number of molecules and not on their diversity.
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Affiliation(s)
- Douglas O Mariano
- Laboratory of Biochemistry and Biophysics, Butantan Institute, São Paulo, SP, Brazil
| | - Juliana M Sciani
- Laboratory of Biochemistry and Biophysics, Butantan Institute, São Paulo, SP, Brazil.,São Francisco University, Bragança Paulista, São Paulo, SP, Brazil
| | | | - Carlos Jared
- São Francisco University, Bragança Paulista, São Paulo, SP, Brazil
| | - Katia Conceição
- Laboratory of Peptide Biochemistry, Federal University of São Paulo (Unifesp), São José dos Campos, SP, Brazil
| | - Daniel C Pimenta
- Laboratory of Biochemistry and Biophysics, Butantan Institute, São Paulo, SP, Brazil
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37
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First line of defence: Skin microbiota may protect anurans from infective larval lungworms. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2021; 14:185-189. [PMID: 33898219 PMCID: PMC8056135 DOI: 10.1016/j.ijppaw.2021.02.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 02/07/2023]
Abstract
Functional roles of the rich microbiota of the skin are not fully understood, but include protection against microbial diseases and other environmental challenges. In experimental studies, we show that reducing the microbiota from cane toad (Rhinella marina) skin by gently wiping with absorptive gauze resulted in threefold higher rates of infection by lungworms (Rhabdias pseudosphaerocephala) following standardised exposure to infective skin-penetrating larvae. Higher concentrations of microbial DNA were associated with lower rates of lungworm entry. Our data suggest that microbial activity on the anuran skin comprises an important line of defence against attack by macroparasites as well as by fungi and other microbes.
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38
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Cusaac JPW, Carter ED, Woodhams DC, Robert J, Spatz JA, Howard JL, Lillard C, Graham AW, Hill RD, Reinsch S, McGinnity D, Reeves B, Bemis D, Wilkes RP, Sutton WB, Waltzek TB, Hardman RH, Miller DL, Gray MJ. Emerging Pathogens and a Current-Use Pesticide: Potential Impacts on Eastern Hellbenders. JOURNAL OF AQUATIC ANIMAL HEALTH 2021; 33:24-32. [PMID: 33590581 DOI: 10.1002/aah.10117] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 08/15/2020] [Accepted: 10/05/2020] [Indexed: 06/12/2023]
Abstract
Populations of the eastern hellbender Cryptobranchus alleganiensis alleganiensis have been declining for decades, and emerging pathogens and pesticides are hypothesized to be contributing factors. However, few empirical studies have attempted to test the potential effects of these factors on hellbenders. We simultaneously exposed subadult hellbenders to environmentally relevant concentrations of either Batrachochytrium dendrobatidis (Bd) or a frog virus 3-like ranavirus (RV), a combination of the pathogens, or each pathogen following exposure to a glyphosate herbicide (Roundup). Additionally, we measured the ability of the skin mucosome to inactivate Bd and RV in growth assays. We found that mucosome significantly inactivated RV by an average of 40% but had no negative effects on Bd growth. All treatments that included RV exposure experienced reduced survival compared to controls, and the combination of RV and herbicide resulted in 100% mortality. Histopathology verified RV as the cause of mortality in all RV-exposed treatments. No animals were infected with Bd or died in the Bd-only treatment. Our results suggest that RV exposure may be a significant threat to the survival of subadult hellbenders and that Roundup exposure may potentially exacerbate this threat.
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Affiliation(s)
- J Patrick W Cusaac
- Center for Wildlife Health, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Edward Davis Carter
- Center for Wildlife Health, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, Massachusetts, 02125, USA
| | - Jacques Robert
- University of Rochester Medical Center, Rochester, New York, 14642, USA
| | - Jennifer A Spatz
- Center for Wildlife Health, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Jennifer L Howard
- Center for Wildlife Health and College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Carson Lillard
- Center for Wildlife Health, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Allison W Graham
- Center for Wildlife Health and College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Rachel D Hill
- Center for Wildlife Health, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | | | | | - Bill Reeves
- Tennessee Wildlife Resources Agency, Nashville, Tennessee, 37220, USA
| | - David Bemis
- College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Rebecca P Wilkes
- Department of Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, 47907, USA
| | - William B Sutton
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, Tennessee, 37209, USA
| | - Thomas B Waltzek
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, Florida, 32611, USA
| | - Rebecca H Hardman
- Center for Wildlife Health and College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Debra L Miller
- Center for Wildlife Health and College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Matthew J Gray
- Center for Wildlife Health, University of Tennessee, Knoxville, Tennessee, 37996, USA
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39
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Winter is coming-Temperature affects immune defenses and susceptibility to Batrachochytrium salamandrivorans. PLoS Pathog 2021; 17:e1009234. [PMID: 33600433 PMCID: PMC7891748 DOI: 10.1371/journal.ppat.1009234] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 12/08/2020] [Indexed: 12/24/2022] Open
Abstract
Environmental temperature is a key factor driving various biological processes, including immune defenses and host-pathogen interactions. Here, we evaluated the effects of environmental temperature on the pathogenicity of the emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal), using controlled laboratory experiments, and measured components of host immune defense to identify regulating mechanisms. We found that adult and juvenile Notophthalmus viridescens died faster due to Bsal chytridiomycosis at 14°C than at 6 and 22°C. Pathogen replication rates, total available proteins on the skin, and microbiome composition likely drove these relationships. Temperature-dependent skin microbiome composition in our laboratory experiments matched seasonal trends in wild N. viridescens, adding validity to these results. We also found that hydrophobic peptide production after two months post-exposure to Bsal was reduced in infected animals compared to controls, perhaps due to peptide release earlier in infection or impaired granular gland function in diseased animals. Using our temperature-dependent susceptibility results, we performed a geographic analysis that revealed N. viridescens populations in the northeastern United States and southeastern Canada are at greatest risk for Bsal invasion, which shifted risk north compared to previous assessments. Our results indicate that environmental temperature will play a key role in the epidemiology of Bsal and provide evidence that temperature manipulations may be a viable disease management strategy. In 2010, a new skin-eating fungus, Batrachochytrium salamandrivorans (Bsal), was discovered killing salamanders in the Netherlands. Since then, the pathogen has spread to other European countries. Bsal is believed to be from Asia and is being translocated through the international trade of amphibians. To our knowledge, Bsal has not arrived to North America. As a proactive strategy for disease control, we evaluated how a range of environmental temperatures in North America could affect invasion risk of Bsal into a widely distributed salamander species, the eastern newt (Notophthalmus viridescens). Our results show that northeastern USA, southeastern Canada, and the higher elevations of the Appalachian Mountains have the greatest likelihood of Bsal invasion, when temperature-dependent susceptibility is included in risk analyses. Changes in eastern newt susceptibility to Bsal infection associated with temperature are likely an interaction between pathogen replication rate and host immune defenses, including changes in skin microbiome composition and the host’s ability to produce Bsal-killing proteins on the skin. Our study provides new insights into how latitude, elevation and season can impact the epidemiology of Bsal, and suggests that strategies that manipulate microclimate of newt habitats could be useful in managing Bsal outbreaks and that climate change will impact Bsal invasion probability.
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40
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Jervis P, Pintanel P, Hopkins K, Wierzbicki C, Shelton JMG, Skelly E, Rosa GM, Almeida-Reinoso D, Eugenia-Ordoñez M, Ron S, Harrison X, Merino-Viteri A, Fisher MC. Post-epizootic microbiome associations across communities of neotropical amphibians. Mol Ecol 2021; 30:1322-1335. [PMID: 33411382 DOI: 10.1111/mec.15789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/31/2022]
Abstract
Microbiome-pathogen interactions are increasingly recognized as an important element of host immunity. While these host-level interactions will have consequences for community disease dynamics, the factors which influence host microbiomes at larger scales are poorly understood. We here describe landscape-scale pathogen-microbiome associations within the context of post-epizootic amphibian chytridiomycosis, a disease caused by the panzootic chytrid fungus Batrachochytrium dendrobatidis. We undertook a survey of Neotropical amphibians across altitudinal gradients in Ecuador ~30 years following the observed amphibian declines and collected skin swab-samples which were metabarcoded using both fungal (ITS-2) and bacterial (r16S) amplicons. The data revealed marked variation in patterns of both B. dendrobatidis infection and microbiome structure that are associated with host life history. Stream breeding amphibians were most likely to be infected with B. dendrobatidis. This increased probability of infection was further associated with increased abundance and diversity of non-Batrachochytrium chytrid fungi in the skin and environmental microbiome. We also show that increased alpha diversity and the relative abundance of fungi are lower in the skin microbiome of adult stream amphibians compared to adult pond-breeding amphibians, an association not seen for bacteria. Finally, stream tadpoles exhibit lower proportions of predicted protective microbial taxa than pond tadpoles, suggesting reduced biotic resistance. Our analyses show that host breeding ecology strongly shapes pathogen-microbiome associations at a landscape scale, a trait that may influence resilience in the face of emerging infectious diseases.
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Affiliation(s)
- Phillip Jervis
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College, London, UK.,Institute of Zoology, Zoological Society of London, London, UK.,Department of Chemistry, UCL, London, UK.,Laboratorio de Ecofisiología and Museo de Zoología (QCAZ), Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Pol Pintanel
- Laboratorio de Ecofisiología and Museo de Zoología (QCAZ), Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador.,Department of Evolutionary Ecology, Estación Biológica de Doñana, CSIC, Sevilla, Spain
| | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London, London, UK
| | - Claudia Wierzbicki
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College, London, UK.,Institute of Zoology, Zoological Society of London, London, UK
| | - Jennifer M G Shelton
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College, London, UK
| | - Emily Skelly
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College, London, UK.,Institute of Zoology, Zoological Society of London, London, UK
| | - Gonçalo M Rosa
- Institute of Zoology, Zoological Society of London, London, UK.,Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Diego Almeida-Reinoso
- Museo de Zoologίa (QCAZ), Escuela de Ciencias Biológicas, Pontificia Universidad Catόlica del Ecuador, Quito, Ecuador.,SARgrillo: Ex situ Management Program of Endangered Amphibians and Insect Breeding program, Quito, Ecuador
| | - Maria Eugenia-Ordoñez
- Fungario QCAM, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Santiago Ron
- Museo de Zoologίa (QCAZ), Escuela de Ciencias Biológicas, Pontificia Universidad Catόlica del Ecuador, Quito, Ecuador
| | - Xavier Harrison
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - Andrés Merino-Viteri
- Laboratorio de Ecofisiología and Museo de Zoología (QCAZ), Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College, London, UK
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41
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Nocera FP, De Filippis A, Piscopo N, Esposito L, De Martino L. Similarities between skin culturable bacterial species of pool frogs (Pelophylax lessonae) and their habitat. BULGARIAN JOURNAL OF VETERINARY MEDICINE 2021. [DOI: 10.15547/bjvm.2019-0054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aim of the present study was to investigate the culturable microflora of pool frogs (Pelophylax lessonae) and their belonging aquatic environment. A total of 60 samples (56 frog cutaneous swabs, 4 water samples) were inoculated onto different selective and differential agar plates to isolate Gram-positive and Gram-negative bacteria or yeasts. Microbial investigation of the water hosting frogs was also performed. Isolates were identified by API system and their antibiotic resistance profiles were evaluated by disk diffusion method on Mueller Hinton agar plates. Aeromonas hydrophila and Enterococcus durans were detected in almost all collected samples. Many of the bacterial isolates showed multidrug-resistant profiles. Importantly, this study highlights that skin frog microbiota is correlated to the belonging environment, and, moreover, some isolated bacterial strains resulted to be of interest in animal and public health, since the park was frequented by visitors of all ages.
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42
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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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43
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Adams AJ, Pessier A, Cranston P, Grasso RL. Chytridiomycosis-induced mortality in a threatened anuran. PLoS One 2020; 15:e0241119. [PMID: 33156870 PMCID: PMC7647137 DOI: 10.1371/journal.pone.0241119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 08/26/2020] [Indexed: 11/20/2022] Open
Abstract
Effectively planning conservation introductions involves assessing the
suitability of both donor and recipient populations, including the landscape of
disease risk. Chytridiomycosis, caused by the fungal pathogen
Batrachochytrium dendrobatidis (Bd), has caused extensive
amphibian declines globally and may hamper reintroduction attempts. To determine
Bd dynamics in potential source populations for conservation translocations of
the threatened California red-legged frog (Rana draytonii) to
Yosemite National Park, we conducted Bd sampling in two populations in the
foothills of the Sierra Nevada Mountains, California, U.S.A. At one of two
sites, we observed lethally high Bd loads in early post-metamorphic life stages
and confirmed one chytridiomycosis-induced mortality, the first such report for
this species. These results informed source population site selection for
subsequent R. draytonii conservation
translocations. Conservation efforts aimed at establishing new populations of
R. draytonii in a landscape where Bd is
ubiquitous can benefit from an improved understanding of risk through disease
monitoring and ex situ infection studies.
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Affiliation(s)
- Andrea J. Adams
- Yosemite National Park, El Portal, California, United States of
America
- Earth Research Institute, University of California Santa Barbara, Santa
Barbara, California, United States of America
- * E-mail:
| | - Allan Pessier
- Department of Veterinary Microbiology and Pathology, College of
Veterinary Medicine, Washington State University, Pullman, Washington, United
States of America
| | - Peggy Cranston
- Mother Lode Field Office, U.S. Bureau of Land Management, Fair Oaks,
California, United States of America
| | - Robert L. Grasso
- Yosemite National Park, El Portal, California, United States of
America
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44
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Grogan LF, Humphries JE, Robert J, Lanctôt CM, Nock CJ, Newell DA, McCallum HI. Immunological Aspects of Chytridiomycosis. J Fungi (Basel) 2020; 6:jof6040234. [PMID: 33086692 PMCID: PMC7712659 DOI: 10.3390/jof6040234] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 12/27/2022] Open
Abstract
Amphibians are currently the most threatened vertebrate class, with the disease chytridiomycosis being a major contributor to their global declines. Chytridiomycosis is a frequently fatal skin disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). The severity and extent of the impact of the infection caused by these pathogens across modern Amphibia are unprecedented in the history of vertebrate infectious diseases. The immune system of amphibians is thought to be largely similar to that of other jawed vertebrates, such as mammals. However, amphibian hosts are both ectothermic and water-dependent, which are characteristics favouring fungal proliferation. Although amphibians possess robust constitutive host defences, Bd/Bsal replicate within host cells once these defences have been breached. Intracellular fungal localisation may contribute to evasion of the induced innate immune response. Increasing evidence suggests that once the innate defences are surpassed, fungal virulence factors suppress the targeted adaptive immune responses whilst promoting an ineffectual inflammatory cascade, resulting in immunopathology and systemic metabolic disruption. Thus, although infections are contained within the integument, crucial homeostatic processes become compromised, leading to mortality. In this paper, we present an integrated synthesis of amphibian post-metamorphic immunological responses and the corresponding outcomes of infection with Bd, focusing on recent developments within the field and highlighting future directions.
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Affiliation(s)
- Laura F. Grogan
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Southport, QLD 4222, Australia;
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia; (J.E.H.); (D.A.N.)
- Correspondence:
| | - Josephine E. Humphries
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia; (J.E.H.); (D.A.N.)
| | - Jacques Robert
- University of Rochester Medical Center, Rochester, NY 14642, USA;
| | - Chantal M. Lanctôt
- Australian Rivers Institute, Griffith University, Southport, QLD 4222, Australia;
| | - Catherine J. Nock
- Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia;
| | - David A. Newell
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia; (J.E.H.); (D.A.N.)
| | - Hamish I. McCallum
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Southport, QLD 4222, Australia;
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45
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Rodriguez KM, Voyles J. The amphibian complement system and chytridiomycosis. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 333:706-719. [PMID: 33052039 PMCID: PMC7821119 DOI: 10.1002/jez.2419] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/26/2020] [Accepted: 09/24/2020] [Indexed: 12/26/2022]
Abstract
Understanding host immune function and ecoimmunology is increasingly important at a time when emerging infectious diseases (EIDs) threaten wildlife. One EID that has emerged and spread widely in recent years is chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), which is implicated unprecedented amphibian declines around the world. The impacts of Bd have been severe for many amphibian species, but some populations have exhibited signs of persistence, and even recovery, in some regions. Many mechanisms may underpin this pattern and amphibian immune responses are likely one key component. Although we have made great strides in understanding amphibian immunity, the complement system remains poorly understood. The complement system is a nonspecific, innate immune defense that is known to enhance other immune responses. Complement activation can occur by three different biochemical pathways and result in protective mechanisms, such as inflammation, opsonization, and pathogen lysis, thereby providing protection to the host. We currently lack an understanding of complement pathway activation for chytridiomycosis, but several studies have suggested that it may be a key part of an early and robust immune response that confers host resistance. Here, we review the available research on the complement system in general as well as amphibian complement responses to Bd infection. Additionally, we propose future research directions that will increase our understanding of the amphibian complement system and other immune responses to Bd. Finally, we suggest how a deeper understanding of amphibian immunity could enhance the conservation and management of amphibian species that are threatened by chytridiomycosis.
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Affiliation(s)
| | - Jamie Voyles
- Department of Biology, University of Nevada-Reno, Reno, Nevada, USA
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46
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Bell SC, Heard GW, Berger L, Skerratt LF. Connectivity over a disease risk gradient enables recovery of rainforest frogs. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02152. [PMID: 32343856 DOI: 10.1002/eap.2152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/14/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Chytridiomycosis has been a key driver of global frog declines and extinctions, particularly for high-altitude populations across Australia and the Americas. While recent evidence shows some species are recovering, the extent of such recoveries and the mechanisms underpinning them remain poorly resolved. We surveyed the historical latitudinal and elevational range of four Australian rainforest frogs that disappeared from upland sites between 1989 and 1994 to establish their contemporary distribution and elevational limits, and investigate factors affecting population recovery. Five rainforest streams were surveyed from mountain-base to summit (30 sites in total), with swabs collected from the target species (Litoria dayi, L. nannotis, L. rheocola, and L. serrata) to determine their infection status, and data loggers deployed to measure microclimatic variation across the elevational gradient. Infection probability increased with elevation and canopy cover as it was tightly and inversely correlated with stream-side air temperature. Occupancy patterns suggest varying responses to this disease threat gradient. Two species, L. rheocola and L. serrata, were found over their full historical elevational range (≥1,000 m above sea level [asl]), while L. dayi was not detected above 400 m (formerly known up to 900 m asl) and L. nannotis was not detected above 800 m (formerly known up to 1,200 m asl). Site occupancy probability was negatively related to predicted infection prevalence for L. dayi, L. nannotis, and L. rheocola, but not L. serrata, which appears to now tolerate high fungal burdens. This study highlights the importance of environmental refuges and connectivity across disease risk gradients for the persistence and natural recovery of frogs susceptible to chytridiomycosis. Likewise, in documenting both interspecific variation in recovery rates and intraspecific differences between sites, this study suggests interactions between disease threats and host selection exist that could be manipulated. For example, translocations may be warranted where connectivity is poor or the increase in disease risk is too steep to allow recolonization, combined with assisted selection or use of founders from populations that have already undergone natural selection.
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Affiliation(s)
- Sara C Bell
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Geoffrey W Heard
- Institute of Land, Water and Society, Charles Sturt University, Albury, New South Wales, 2640, Australia
- Victorian Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria, 3084, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
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Preuss JF, Greenspan SE, Rossi EM, Lucas Gonsales EM, Neely WJ, Valiati VH, Woodhams DC, Becker CG, Tozetti AM. Widespread Pig Farming Practice Linked to Shifts in Skin Microbiomes and Disease in Pond-Breeding Amphibians. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11301-11312. [PMID: 32845628 DOI: 10.1021/acs.est.0c03219] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Farming practices may reshape the structure of watersheds, water quality, and the health of aquatic organisms. Nutrient enrichment from agricultural pollution increases disease pressure in many host-pathogen systems, but the mechanisms underlying this pattern are not always resolved. For example, nutrient enrichment should strongly influence pools of aquatic environmental bacteria, which has the potential to alter microbiome composition of aquatic animals and their vulnerability to disease. However, shifts in the host microbiome have received little attention as a link between nutrient enrichment and diseases of aquatic organisms. We examined nutrient enrichment through the widespread practice of integrated pig-fish farming and its effects on microbiome composition of Brazilian amphibians and prevalence of the globally distributed amphibian skin pathogen Batrachochytrium dendrobatidis (Bd). This farming system drove surges in fecal coliform bacteria, disturbing amphibian skin bacterial communities such that hosts recruited higher proportions of Bd-facilitative bacteria and carried higher Bd prevalence. Our results highlight previously overlooked connections between global trends in land use change, microbiome dysbiosis, and wildlife disease. These interactions may be particularly important for disease management in the tropics, a region with both high biodiversity and continually intensifying anthropogenic pressures on aquatic wildlife habitats.
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Affiliation(s)
- Jackson F Preuss
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
- Departamento de Ciências da Vida, Universidade do Oeste de Santa Catarina, São Miguel do Oeste, SC 89900-000, Brazil
| | - Sasha E Greenspan
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Eliandra M Rossi
- Departamento de Ciências da Vida, Universidade do Oeste de Santa Catarina, São Miguel do Oeste, SC 89900-000, Brazil
| | - Elaine M Lucas Gonsales
- Departamento de Zootecnia e Ciências Biológicas, Universidade Federal de Santa Maria, RS 98300-000, Brazil
| | - Wesley J Neely
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Victor Hugo Valiati
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, Massachusetts 02125, United States
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Alexandro M Tozetti
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
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48
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Goessens T, Huysman S, De Troyer N, Deknock A, Goethals P, Lens L, Vanhaecke L, Croubels S. Multi-class analysis of 46 antimicrobial drug residues in pond water using UHPLC-Orbitrap-HRMS and application to freshwater ponds in Flanders, Belgium. Talanta 2020; 220:121326. [PMID: 32928381 DOI: 10.1016/j.talanta.2020.121326] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 01/27/2023]
Abstract
Increasing anthropogenic pressure and agricultural pollution raises concerns regarding antimicrobial resistance and biodiversity loss in aquatic environments. In order to protect and restore water resources and biodiversity, antimicrobial drug residues should be monitored in all aquatic environments including pond water. Consequently, the objective of this research was to develop and validate a novel multi-residue method for the simultaneous quantification of 46 targeted human and veterinary antimicrobial drugs in pond water. A suitable extraction method based on solid-phase extraction (SPE) was developed, assisted by a fractional factorial design. A broad polarity range of compounds was covered (log P from -4.05 to 4.38), including major representatives of the following classes: sulfonamides, tetracyclines, quinolones, macrolides, lincosamides, nitrofurans, penicillins, cephalosporins, diaminopyrimidines, pleuromutilins and phenicols. All analytes were separated using ultra-high performance liquid chromatography (UHPLC) and detected in full-scan by Orbitrap high resolution mass spectrometry (Orbitrap-HRMS). Good linearity was obtained for all compounds with R2 ≥ 0.993 and goodness-of-fit coefficient (g) ≤ 11.56%. Method detection limits ranged from 10 to 50 ng L-1 and method quantification limits were 50 ng L-1 for all compounds. Acceptable values were obtained for within-day and between-day apparent recoveries (i.e. between 50 and 120%), precision (< 30% and < 45%) and measurement uncertainty (< 50%). Targeted analysis of 18 freshwater ponds throughout Flanders was performed to demonstrate the applicability of the newly developed UHPLC-HRMS method. Overall, 20 antimicrobial drugs were detected with highest concentrations observed for tetracyclines and their transformation products ranging between 51 and 248 ng L-1. Finally, suspect screening was performed suggesting the presence of 14 additional pharmaceuticals including 3 antimicrobial degradation products (e.g. apo-oxytetracycline, amoxicillin penicilloic acid and penilloic acid) and 11 pesticides.
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Affiliation(s)
- T Goessens
- Ghent University, Faculty of Veterinary Medicine, Department of Pharmacology, Toxicology and Biochemistry, Laboratory of Pharmacology and Toxicology, Merelbeke, Belgium
| | - S Huysman
- Ghent University, Faculty of Veterinary Medicine, Department of Veterinary Public Health and Food Safety, Laboratory of Chemical Analysis, Merelbeke, Belgium
| | - N De Troyer
- Ghent University, Faculty of Bioscience Engineering, Department of Animal Science and Aquatic Ecology, Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, Belgium
| | - A Deknock
- Ghent University, Faculty of Bioscience Engineering, Department of Animal Science and Aquatic Ecology, Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, Belgium
| | - P Goethals
- Ghent University, Faculty of Bioscience Engineering, Department of Animal Science and Aquatic Ecology, Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, Belgium
| | - L Lens
- Ghent University, Faculty of Sciences, Department of Biology, Terrestrial Ecology Unit, Ghent, Belgium
| | - L Vanhaecke
- Ghent University, Faculty of Veterinary Medicine, Department of Veterinary Public Health and Food Safety, Laboratory of Chemical Analysis, Merelbeke, Belgium; Queen's University, School of Biological Sciences, Institute for Global Food Security, Belfast, Ireland
| | - S Croubels
- Ghent University, Faculty of Veterinary Medicine, Department of Pharmacology, Toxicology and Biochemistry, Laboratory of Pharmacology and Toxicology, Merelbeke, Belgium.
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49
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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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50
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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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