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Thumsová B, González-Miras E, Rubio Á, Granados I, Bates KA, Bosch J. Author Correction: Chemical disinfection as a simple and reliable method to control the amphibian chytrid fungus at breeding points of endangered amphibians. Sci Rep 2024; 14:6721. [PMID: 38509212 PMCID: PMC10954648 DOI: 10.1038/s41598-024-57246-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024] Open
Affiliation(s)
- Barbora Thumsová
- Asociación Herpetológica Española (AHE), Madrid, Spain
- Museo Nacional de Ciencias Naturales-CSIC, 28006, Madrid, Spain
- IMIB-Research Unit of Biodiversity (University of Oviedo, CSIC, Principality of Asturias), 33600, Mieres, Spain
| | - Emilio González-Miras
- Agencia de Medio Ambiente y Agua de Andalucía, Consejería de Sostenibilidad, Medio Ambiente y Economía Azul, Junta de Andalucía, Seville, Spain
| | - Ángel Rubio
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain
| | - Ignacio Granados
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain
| | - Kieran A Bates
- Centre for Immunobiology, The Blizard Institute, Queen Mary University of London, London, E1 2AT, UK
| | - Jaime Bosch
- IMIB-Research Unit of Biodiversity (University of Oviedo, CSIC, Principality of Asturias), 33600, Mieres, Spain.
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain.
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Thumsová B, González-Miras E, Rubio Á, Granados I, Bates KA, Bosch J. Chemical disinfection as a simple and reliable method to control the amphibian chytrid fungus at breeding points of endangered amphibians. Sci Rep 2024; 14:5151. [PMID: 38431740 PMCID: PMC10908824 DOI: 10.1038/s41598-024-55946-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/29/2024] [Indexed: 03/05/2024] Open
Abstract
Chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is pushing amphibians towards extinction. Whilst mitigation methods were suggested a decade ago, we lack field trials testing their efficacy. We used the agrochemical fungicide, tebuconazole, to treat Bd infected breeding waterbodies of an endangered species that is highly susceptible to the fungus. Just two applications of tebuconazole led to a significant reduction in infection loads in the vast majority of sites, and at six sites the disinfection remained one/two-years post-application. Tebuconazole values drastically decreased in the waterbodies within a week after application, with no significant effects on their hydrochemical and hydrobiological characteristics. Although the use of chemicals in natural populations is undesirable, the growing existential threat to amphibians all over the world indicates that effective interventions in selected populations of endangered species are urgently needed.
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Affiliation(s)
- Barbora Thumsová
- Asociación Herpetológica Española (AHE), Madrid, Spain
- Museo Nacional de Ciencias Naturales-CSIC, 28006, Madrid, Spain
- IMIB-Research Unit of Biodiversity (University of Oviedo, CSIC, Principality of Asturias), 33600, Mieres, Spain
| | - Emilio González-Miras
- Agencia de Medio Ambiente y Agua de Andalucía, Consejería de Sostenibilidad, Medio Ambiente y Economía Azul, Junta de Andalucía, Seville, Spain
| | - Ángel Rubio
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain
| | - Ignacio Granados
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain
| | - Kieran A Bates
- Centre for Immunobiology, The Blizard Institute, Queen Mary University of London, London, E1 2AT, UK
| | - Jaime Bosch
- IMIB-Research Unit of Biodiversity (University of Oviedo, CSIC, Principality of Asturias), 33600, Mieres, Spain.
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain.
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Hanski E, Khanyari M, Li J, Bates KA, Zuther S, Maiden MCJ, Kock R, Knowles SCL. Gut microbiota of the critically endangered Saiga antelope across two wild populations in a year without mass mortality. Sci Rep 2023; 13:17236. [PMID: 37821478 PMCID: PMC10567781 DOI: 10.1038/s41598-023-44393-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 10/07/2023] [Indexed: 10/13/2023] Open
Abstract
The Saiga are migratory antelopes inhabiting the grasslands of Eurasia. Over the last century, Saiga have been pushed to the brink of extinction by mass mortality events and intense poaching. Yet, despite the high profile of the Saiga as an animal of conservation concern, little is known of its biology. In particular, the gut microbiota of Saiga has not been studied, despite its potential importance in health. Here, we characterise the gut microbiota of Saiga from two geographically distinct populations in Kazakhstan and compare it with that of other antelope species. We identified a consistent gut microbial diversity and composition among individuals and across two Saiga populations during a year without die-offs, with over 85% of bacterial genera being common to both populations despite vast geographic separation. We further show that the Saiga gut microbiota resembled that of five other antelopes. The putative causative agent of Saiga mass die-offs, Pasteurella multocida, was not detected in the Saiga microbiota. Our findings provide the first description of the Saiga gut microbiota, generating a baseline for future work investigating the microbiota's role in health and mass die-offs, and supporting the conservation of this critically endangered species.
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Affiliation(s)
- Eveliina Hanski
- Department of Biology, University of Oxford, Oxford, UK.
- Faculty of Medicine, University of Helsinki, Helsinki, Finland.
| | | | - Jingdi Li
- Department of Biology, University of Oxford, Oxford, UK
| | | | - Steffen Zuther
- Association for the Conservation of Biodiversity of Kazakhstan, Astana, Kazakhstan
- Frankfurt Zoological Society, Frankfurt, Germany
| | | | - Richard Kock
- Centre for Emerging, Endemic and Exotic Diseases, The Royal Veterinary College, University of London, London, UK
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Li J, Bates KA, Hoang KL, Hector TE, Knowles SCL, King KC. Experimental temperatures shape host microbiome diversity and composition. Glob Chang Biol 2023; 29:41-56. [PMID: 36251487 PMCID: PMC10092218 DOI: 10.1111/gcb.16429] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/20/2022] [Indexed: 05/10/2023]
Abstract
Global climate change has led to more extreme thermal events. Plants and animals harbour diverse microbial communities, which may be vital for their physiological performance and help them survive stressful climatic conditions. The extent to which microbiome communities change in response to warming or cooling may be important for predicting host performance under global change. Using a meta-analysis of 1377 microbiomes from 43 terrestrial and aquatic species, we found a decrease in the amplicon sequence variant-level microbiome phylogenetic diversity and alteration of microbiome composition under both experimental warming and cooling. Microbiome beta dispersion was not affected by temperature changes. We showed that the host habitat and experimental factors affected microbiome diversity and composition more than host biological traits. In particular, aquatic organisms-especially in marine habitats-experienced a greater depletion in microbiome diversity under cold conditions, compared to terrestrial hosts. Exposure involving a sudden long and static temperature shift was associated with microbiome diversity loss, but this reduction was attenuated by prior-experimental lab acclimation or when a ramped regime (i.e., warming) was used. Microbial differential abundance and co-occurrence network analyses revealed several potential indicator bacterial classes for hosts in heated environments and on different biome levels. Overall, our findings improve our understanding on the impact of global temperature changes on animal and plant microbiome structures across a diverse range of habitats. The next step is to link these changes to measures of host fitness, as well as microbial community functions, to determine whether microbiomes can buffer some species against a more thermally variable and extreme world.
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Affiliation(s)
- Jingdi Li
- Department of BiologyUniversity of OxfordOxfordUK
| | | | - Kim L. Hoang
- Department of BiologyUniversity of OxfordOxfordUK
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Bates KA, Friesen J, Loyau A, Butler H, Vredenburg VT, Laufer J, Chatzinotas A, Schmeller DS. Environmental and Anthropogenic Factors Shape the Skin Bacterial Communities of a Semi-Arid Amphibian Species. Microb Ecol 2022:10.1007/s00248-022-02130-5. [PMID: 36445401 DOI: 10.1007/s00248-022-02130-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
The amphibian skin microbiome is important in maintaining host health, but is vulnerable to perturbation from changes in biotic and abiotic conditions. Anthropogenic habitat disturbance and emerging infectious diseases are both potential disrupters of the skin microbiome, in addition to being major drivers of amphibian decline globally. We investigated how host environment (hydrology, habitat disturbance), pathogen presence, and host biology (life stage) impact the skin microbiome of wild Dhofar toads (Duttaphrynus dhufarensis) in Oman. We detected ranavirus (but not Batrachochytrium dendrobatidis) across all sampling sites, constituting the first report of this pathogen in Oman, with reduced prevalence in disturbed sites. We show that skin microbiome beta diversity is driven by host life stage, water source, and habitat disturbance, but not ranavirus infection. Finally, although trends in bacterial diversity and differential abundance were evident in disturbed versus undisturbed sites, bacterial co-occurrence patterns determined through network analyses revealed high site specificity. Our results therefore provide support for amphibian skin microbiome diversity and taxa abundance being associated with habitat disturbance, with bacterial co-occurrence (and likely broader aspects of microbial community ecology) being largely site specific.
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Affiliation(s)
- K A Bates
- Department of Zoology, University of Oxford, Oxford, UK.
| | - J Friesen
- Centre for Environmental Biotechnology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - A Loyau
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, INPT, UPS, Toulouse, France
| | - H Butler
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - V T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - J Laufer
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - A Chatzinotas
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
- Institute of Biology, Leipzig University, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, Germany
| | - D S Schmeller
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, INPT, UPS, Toulouse, France
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Wu-Chuang A, Bates KA, Obregon D, Estrada-Peña A, King KC, Cabezas-Cruz A. Rapid evolution of a novel protective symbiont into keystone taxon in Caenorhabditis elegans microbiota. Sci Rep 2022; 12:14045. [PMID: 35982076 PMCID: PMC9388637 DOI: 10.1038/s41598-022-18269-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 08/08/2022] [Indexed: 11/09/2022] Open
Abstract
Protective microbes have a major role in shaping host-pathogen interactions, but their relative importance in the structure of the host microbiota remains unclear. Here, we used a network approach to characterize the impact of a novel, experimentally evolved 'protective microbial symbiont' (Enterococcus faecalis) on the structure and predicted function of the natural microbiota of the model organism Caenorhabditis elegans. We used microbial network analysis to identify keystone taxa and describe the hierarchical placement of protective and non-protective symbionts in the microbiota. We found that early colonization with symbionts produce statistically significant changes in the structure of the community. Notably, only the protective E. faecalis became a keystone taxon in the nematode microbiota. Non-protective lineages of the same bacterial species remained comparatively unimportant to the community. Prediction of functional profiles in bacterial communities using PICRUSt2 showed that the presence of highly protective E. faecalis decreased the abundance of ergothioneine (EGT) biosynthesis pathway involved in the synthesis of the antioxidant molecule EGT, a potential public good. These data show that in addition to direct antagonism with virulent pathogens, keystone protective symbionts are linked to modified bacterial community structure and possible reductions in public goods, potentially driving decreased antioxidant defense. We suggest that this response could suppress infection via wholesale microbial community changes to further benefit the host. These findings extend the concept of protective symbionts beyond bodyguards to ecosystem engineers.
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Affiliation(s)
- Alejandra Wu-Chuang
- Anses, INRAE, Ecole Nationale Vétérinaire d'Alfort, UMR BIPAR, Laboratoire de Santé Animale, 94700, Maisons-Alfort, France
| | - Kieran A Bates
- Department of Zoology, University of Oxford, Oxford, OX1 3SZ, UK
| | - Dasiel Obregon
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | | | - Kayla C King
- Department of Zoology, University of Oxford, Oxford, OX1 3SZ, UK.
| | - Alejandro Cabezas-Cruz
- Anses, INRAE, Ecole Nationale Vétérinaire d'Alfort, UMR BIPAR, Laboratoire de Santé Animale, 94700, Maisons-Alfort, France.
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Bates KA, Higgins C, Neiman M, King KC. Turning the tide on sex and the microbiota in aquatic animals. Hydrobiologia 2022; 850:3823-3835. [PMID: 37662671 PMCID: PMC10468917 DOI: 10.1007/s10750-022-04862-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/08/2022] [Accepted: 03/10/2022] [Indexed: 09/05/2023]
Abstract
Sex-based differences in animal microbiota are increasingly recognized as of biological importance. While most animal biomass is found in aquatic ecosystems and many water-dwelling species are of high economic and ecological value, biological sex is rarely included as an explanatory variable in studies of the aquatic animal microbiota. In this opinion piece, we argue for greater consideration of host sex in studying the microbiota of aquatic animals, emphasizing the many advancements that this information could provide in the life sciences, from the evolution of sex to aquaculture.
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Affiliation(s)
- Kieran A. Bates
- Department of Zoology, University of Oxford, Oxford, OX1 3SZ UK
| | - Chelsea Higgins
- Department of Biology, University of Iowa, Iowa City, IW 52245 USA
| | - Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, IW 52245 USA
- Department of Gender, Women’s, and Sexuality Studies, University of Iowa, Iowa City, IW 52245 USA
| | - Kayla C. King
- Department of Zoology, University of Oxford, Oxford, OX1 3SZ UK
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Bates KA, Sommer U, Hopkins KP, Shelton JMG, Wierzbicki C, Sergeant C, Tapley B, Michaels CJ, Schmeller DS, Loyau A, Bosch J, Viant MR, Harrison XA, Garner TWJ, Fisher MC. Microbiome function predicts amphibian chytridiomycosis disease dynamics. Microbiome 2022; 10:44. [PMID: 35272699 PMCID: PMC8908643 DOI: 10.1186/s40168-021-01215-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 12/10/2021] [Indexed: 05/07/2023]
Abstract
BACKGROUND The fungal pathogen Batrachochytrium dendrobatidis (Bd) threatens amphibian biodiversity and ecosystem stability worldwide. Amphibian skin microbial community structure has been linked to the clinical outcome of Bd infections, yet its overall functional importance is poorly understood. METHODS Microbiome taxonomic and functional profiles were assessed using high-throughput bacterial 16S rRNA and fungal ITS2 gene sequencing, bacterial shotgun metagenomics and skin mucosal metabolomics. We sampled 56 wild midwife toads (Alytes obstetricans) from montane populations exhibiting Bd epizootic or enzootic disease dynamics. In addition, to assess whether disease-specific microbiome profiles were linked to microbe-mediated protection or Bd-induced perturbation, we performed a laboratory Bd challenge experiment whereby 40 young adult A. obstetricans were exposed to Bd or a control sham infection. We measured temporal changes in the microbiome as well as functional profiles of Bd-exposed and control animals at peak infection. RESULTS Microbiome community structure and function differed in wild populations based on infection history and in experimental control versus Bd-exposed animals. Bd exposure in the laboratory resulted in dynamic changes in microbiome community structure and functional differences, with infection clearance in all but one infected animal. Sphingobacterium, Stenotrophomonas and an unclassified Commamonadaceae were associated with wild epizootic dynamics and also had reduced abundance in laboratory Bd-exposed animals that cleared infection, indicating a negative association with Bd resistance. This was further supported by microbe-metabolite integration which identified functionally relevant taxa driving disease outcome, of which Sphingobacterium and Bd were most influential in wild epizootic dynamics. The strong correlation between microbial taxonomic community composition and skin metabolome in the laboratory and field is inconsistent with microbial functional redundancy, indicating that differences in microbial taxonomy drive functional variation. Shotgun metagenomic analyses support these findings, with similar disease-associated patterns in beta diversity. Analysis of differentially abundant bacterial genes and pathways indicated that bacterial environmental sensing and Bd resource competition are likely to be important in driving infection outcomes. CONCLUSIONS Bd infection drives altered microbiome taxonomic and functional profiles across laboratory and field environments. Our application of multi-omics analyses in experimental and field settings robustly predicts Bd disease dynamics and identifies novel candidate biomarkers of infection. Video Abstract.
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Affiliation(s)
- Kieran A Bates
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK.
- MRC Centre for GlobaI Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, W2 1PG, UK.
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
| | - Ulf Sommer
- NERC Biomolecular Analysis Facility - Metabolomics Node (NBAF-B), School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Kevin P Hopkins
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Jennifer M G Shelton
- MRC Centre for GlobaI Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, W2 1PG, UK
| | - Claudia Wierzbicki
- MRC Centre for GlobaI Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, W2 1PG, UK
| | - Christopher Sergeant
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Benjamin Tapley
- ZSL London Zoo, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | | | - Dirk S Schmeller
- Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UPS), Toulouse, France
| | - Adeline Loyau
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, 16775, Stechlin, Germany
| | - Jaime Bosch
- IMIB Biodiversity Research Institute (CSIC-University of Oviedo), 33600, Mieres, Spain
| | - Mark R Viant
- NERC Biomolecular Analysis Facility - Metabolomics Node (NBAF-B), School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Xavier A Harrison
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4DQ, UK
| | - Trenton W J Garner
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Matthew C Fisher
- MRC Centre for GlobaI Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, W2 1PG, UK
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Affiliation(s)
- Kieran A Bates
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK.
| | - Kayla C King
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK
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Bates KA, Bolton JS, King KC. A globally ubiquitous symbiont can drive experimental host evolution. Mol Ecol 2021; 30:3882-3892. [PMID: 34037279 DOI: 10.1111/mec.15998] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 01/04/2023]
Abstract
Organisms harbour myriad microbes which can be parasitic or protective against harm. The costs and benefits resulting from these symbiotic relationships can be context-dependent, but the evolutionary consequences to hosts of these transitions remain unclear. Here, we mapped the Leucobacter genus across 13,715 microbiome samples (163 studies) to reveal a global distribution as a free-living microbe or a symbiont of animals and plants. We showed that across geographically distant locations (South Africa, France, Cape Verde), Leucobacter isolates vary substantially in their virulence to an associated animal host, Caenorhabditis nematodes. We further found that multiple Leucobacter sequence variants co-occur in wild Caenorhabditis spp. which combined with natural variation in virulence provides real-world potential for Leucobacter community composition to influence host fitness. We examined this by competing C. elegans genotypes that differed in susceptibility to different Leucobacter species in an evolution experiment. One Leucobacter species was found to be host-protective against another, virulent parasitic species. We tested the impact of host genetic background and Leucobacter community composition on patterns of host-based defence evolution. We found host genotypes conferring defence against the parasitic species were maintained during infection. However, when hosts were protected during coinfection, host-based defences were nearly lost from the population. Overall, our results provide insight into the role of community context in shaping host evolution during symbioses.
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Affiliation(s)
| | - Jai S Bolton
- Department of Zoology, University of Oxford, Oxford, UK
| | - Kayla C King
- Department of Zoology, University of Oxford, Oxford, UK
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Marcogliese DJ, King KC, Bates KA. Effects of multiple stressors on northern leopard frogs in agricultural wetlands. Parasitology 2021; 148:827-834. [PMID: 33685539 PMCID: PMC11010203 DOI: 10.1017/s003118202100038x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 12/21/2022]
Abstract
Natural and anthropogenic stressors, including parasites and pesticides, may induce oxidative stress in animals. Measuring oxidative stress responses in sentinel species that are particularly responsive to environmental perturbations not only provides insight into host physiology but is also a useful readout of ecosystem health. Newly metamorphosed northern leopard frogs (Lithobates pipiens), a sentinel species, were collected from agricultural and non-agricultural wetlands exposed to varying concentrations of the herbicide atrazine. Significant effects of certain parasites' abundance and their interaction with atrazine exposure on frog oxidative stress were identified. Specifically, increased protein levels were detected in frogs infected with echinostome metacercariae. In addition, the nematode Oswaldocruzia sp. was significantly associated with increased thiol concentration and catalase activity. Significant parasite × atrazine interactions were observed for atrazine exposure and the abundance of Oswaldocruzia sp. on thiol, as thiol concentrations increased with parasite abundance at low atrazine localities and decreased in high atrazine wetlands. In addition, a significant interaction between the abundances of Oswaldocruzia sp. and gorgoderid trematodes on thiol concentrations was observed. These findings demonstrate that studies of oxidative stress on animals in natural ecosystems should account for the confounding effects of parasitism, particularly for amphibians in agricultural landscapes.
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Affiliation(s)
- David J. Marcogliese
- Aquatic Contaminants Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment and Climate Change Canada, St. Lawrence Centre, 105 McGill Street, 7th floor, Montreal, Quebec H2Y 2E7, Canada
- St. Andrews Biological Station, Fisheries and Oceans Canada, 125 Marine Science Drive, St. Andrews, New Brunswick E5B 0E4, Canada
| | - Kayla C. King
- Department of Biology, Concordia University, 1455 de Maisonneuve Blvd. W., Montreal, Quebec H3G 1M8, Canada
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford OX1 3SZ, UK
| | - Kieran A. Bates
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford OX1 3SZ, UK
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Abstract
Animals live in symbiosis with numerous microbe species. While some can protect hosts from infection and benefit host health, components of the microbiota or changes to the microbial landscape have the potential to facilitate infections and worsen disease severity. Pathogens and pathobionts can exploit microbiota metabolites, or can take advantage of a depletion in host defences and changing conditions within a host, to cause opportunistic infection. The microbiota might also favour a more virulent evolutionary trajectory for invading pathogens. In this review, we consider the ways in which a host microbiota contributes to infectious disease throughout the host's life and potentially across evolutionary time. We further discuss the implications of these negative outcomes for microbiota manipulation and engineering in disease management.
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Affiliation(s)
- Emily J. Stevens
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Kieran A. Bates
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Kayla C. King
- Department of Zoology, University of Oxford, Oxford, United Kingdom
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Bates KA, Shelton JMG, Mercier VL, Hopkins KP, Harrison XA, Petrovan SO, Fisher MC. Captivity and Infection by the Fungal Pathogen Batrachochytrium salamandrivorans Perturb the Amphibian Skin Microbiome. Front Microbiol 2019; 10:1834. [PMID: 31507541 PMCID: PMC6716147 DOI: 10.3389/fmicb.2019.01834] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/25/2019] [Indexed: 12/13/2022] Open
Abstract
The emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal) is responsible for the catastrophic decline of European salamanders and poses a threat to amphibians globally. The amphibian skin microbiome can influence disease outcome for several host-pathogen systems, yet little is known of its role in Bsal infection. In addition, many experimental in-vivo amphibian disease studies to date have relied on specimens that have been kept in captivity for long periods without considering the influence of environment on the microbiome and how this may impact the host response to pathogen exposure. We characterized the impact of captivity and exposure to Bsal on the skin bacterial and fungal communities of two co-occurring European newt species, the smooth newt, Lissotriton vulgaris and the great-crested newt, Triturus cristatus. We show that captivity led to significant losses in bacterial and fungal diversity of amphibian skin, which may be indicative of a decline in microbe-mediated protection. We further demonstrate that in both L. vulgaris and T. cristatus, Bsal infection was associated with changes in the composition of skin bacterial communities with possible negative consequences to host health. Our findings advance current understanding of the role of host-associated microbiota in Bsal infection and highlight important considerations for ex-situ amphibian conservation programmes.
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Affiliation(s)
- Kieran A Bates
- Department of Zoology, University of Oxford, Oxford, United Kingdom.,Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom.,Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Jennifer M G Shelton
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
| | - Victoria L Mercier
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
| | - Kevin P Hopkins
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Xavier A Harrison
- Institute of Zoology, Zoological Society of London, London, United Kingdom.,College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Silviu O Petrovan
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Froglife, Peterborough, United Kingdom
| | - Matthew C Fisher
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom
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14
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Abstract
Emerging fungal pathogens are a growing threat to global health, ecosystems, food security, and the world economy. Over the last century, environmental change and globalized transport, twinned with the increasing application of antifungal chemical drugs have led to increases in outbreaks of fungal diseases with sometimes catastrophic effects. In order to tackle contemporary epidemics and predemic threats, there is a pressing need for a unified approach in identification and monitoring of fungal pathogens. In this paper, we discuss current high throughput technologies, as well as new platforms capable of combining diverse data types to inform practical epidemiological strategies with a focus on emerging fungal pathogens of wildlife.
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Affiliation(s)
- Pria N. Ghosh
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Matthew C. Fisher
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Kieran A. Bates
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- Institute of Zoology, Zoological Society of London, London, United Kingdom
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15
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O'Hanlon SJ, Rieux A, Farrer RA, Rosa GM, Waldman B, Bataille A, Kosch TA, Murray KA, Brankovics B, Fumagalli M, Martin MD, Wales N, Alvarado-Rybak M, Bates KA, Berger L, Böll S, Brookes L, Clare F, Courtois EA, Cunningham AA, Doherty-Bone TM, Ghosh P, Gower DJ, Hintz WE, Höglund J, Jenkinson TS, Lin CF, Laurila A, Loyau A, Martel A, Meurling S, Miaud C, Minting P, Pasmans F, Schmeller DS, Schmidt BR, Shelton JMG, Skerratt LF, Smith F, Soto-Azat C, Spagnoletti M, Tessa G, Toledo LF, Valenzuela-Sánchez A, Verster R, Vörös J, Webb RJ, Wierzbicki C, Wombwell E, Zamudio KR, Aanensen DM, James TY, Gilbert MTP, Weldon C, Bosch J, Balloux F, Garner TWJ, Fisher MC. Recent Asian origin of chytrid fungi causing global amphibian declines. Science 2018; 360:621-627. [PMID: 29748278 PMCID: PMC6311102 DOI: 10.1126/science.aar1965] [Citation(s) in RCA: 274] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 03/29/2018] [Indexed: 12/14/2022]
Abstract
Globalized infectious diseases are causing species declines worldwide, but their source often remains elusive. We used whole-genome sequencing to solve the spatiotemporal origins of the most devastating panzootic to date, caused by the fungus Batrachochytrium dendrobatidis, a proximate driver of global amphibian declines. We traced the source of B. dendrobatidis to the Korean peninsula, where one lineage, BdASIA-1, exhibits the genetic hallmarks of an ancestral population that seeded the panzootic. We date the emergence of this pathogen to the early 20th century, coinciding with the global expansion of commercial trade in amphibians, and we show that intercontinental transmission is ongoing. Our findings point to East Asia as a geographic hotspot for B. dendrobatidis biodiversity and the original source of these lineages that now parasitize amphibians worldwide.
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Affiliation(s)
- Simon J O'Hanlon
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK.
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
| | - Adrien Rieux
- CIRAD, UMR PVBMT, 97410 St. Pierre, Reunion, France
| | - Rhys A Farrer
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Gonçalo M Rosa
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
- Department of Biology, University of Nevada, Reno, NV 89557, USA
- Centre for Ecology, Evolution and Environmental Changes (CE3C), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Bruce Waldman
- Laboratory of Behavioral and Population Ecology, School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Arnaud Bataille
- Laboratory of Behavioral and Population Ecology, School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
- CIRAD, UMR ASTRE, F-34398 Montpellier, France
| | - Tiffany A Kosch
- Laboratory of Behavioral and Population Ecology, School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Kris A Murray
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Balázs Brankovics
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584CT Utrecht, Netherlands
- Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, Netherlands
| | - Matteo Fumagalli
- Department of Life Sciences, Silwood Park Campus, Imperial College London, Ascot, UK
- UCL Genetics Institute, University College London, London WC1E 6BT, UK
| | - Michael D Martin
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology (NTNU), Erling Skakkes gate 49, NO-7012 Trondheim, Norway
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
| | - Nathan Wales
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
| | - Mario Alvarado-Rybak
- Centro de Investigación para la Sustentabilidad, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, Republica 440, Santiago, Chile
| | - Kieran A Bates
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
| | - Lee Berger
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Susanne Böll
- Agency for Population Ecology and Nature Conservancy, Gerbrunn, Germany
| | - Lola Brookes
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
| | - Frances Clare
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
| | - Elodie A Courtois
- Laboratoire Ecologie, Évolution, Interactions des Systèmes Amazoniens (LEEISA), Université de Guyane, CNRS, IFREMER, 97300 Cayenne, French Guiana
| | | | | | - Pria Ghosh
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
- Unit for Environmental Sciences and Management, Private Bag x6001, North-West University, Potchefstroom 2520, South Africa
| | - David J Gower
- Life Sciences, Natural History Museum, London SW7 5BD, UK
| | - William E Hintz
- Biology Department, University of Victoria, Victoria, BC V8W 3N5, Canada
| | - Jacob Höglund
- Department of Ecology and Genetics, EBC, Uppsala University, Norbyv. 18D, SE-75236, Uppsala, Sweden
| | - Thomas S Jenkinson
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chun-Fu Lin
- Zoology Division, Endemic Species Research Institute, 1 Ming-shen East Road, Jiji, Nantou 552, Taiwan
| | - Anssi Laurila
- Department of Ecology and Genetics, EBC, Uppsala University, Norbyv. 18D, SE-75236, Uppsala, Sweden
| | - Adeline Loyau
- Department of Conservation Biology, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
- EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Sara Meurling
- Department of Ecology and Genetics, EBC, Uppsala University, Norbyv. 18D, SE-75236, Uppsala, Sweden
| | - Claude Miaud
- PSL Research University, CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, Montpellier, France
| | - Pete Minting
- Amphibian and Reptile Conservation (ARC) Trust, Boscombe, Bournemouth, Dorset BH1 4AP, UK
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Dirk S Schmeller
- Department of Conservation Biology, Helmholtz Centre for Environmental Research-UFZ, 04318 Leipzig, Germany
- EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Benedikt R Schmidt
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland, and Info Fauna Karch, UniMail-Bâtiment G, Bellevaux 51, 2000 Neuchâtel, Switzerland
| | - Jennifer M G Shelton
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Lee F Skerratt
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Freya Smith
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
- National Wildlife Management Centre, APHA, Woodchester Park, Gloucestershire GL10 3UJ, UK
| | - Claudio Soto-Azat
- Centro de Investigación para la Sustentabilidad, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, Republica 440, Santiago, Chile
| | | | - Giulia Tessa
- Non-profit Association Zirichiltaggi-Sardinia Wildlife Conservation, Strada Vicinale Filigheddu 62/C, I-07100 Sassari, Italy
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, Brazil
| | - Andrés Valenzuela-Sánchez
- Centro de Investigación para la Sustentabilidad, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, Republica 440, Santiago, Chile
- ONG Ranita de Darwin, Nataniel Cox 152, Santiago, Chile
| | - Ruhan Verster
- Unit for Environmental Sciences and Management, Private Bag x6001, North-West University, Potchefstroom 2520, South Africa
| | - Judit Vörös
- Collection of Amphibians and Reptiles, Department of Zoology, Hungarian Natural History Museum, Budapest, Baross u. 13., 1088, Hungary
| | - Rebecca J Webb
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Claudia Wierzbicki
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Emma Wombwell
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - David M Aanensen
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
- Centre for Genomic Pathogen Surveillance, Wellcome Genome Campus, Cambridgeshire, UK
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - M Thomas P Gilbert
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology (NTNU), Erling Skakkes gate 49, NO-7012 Trondheim, Norway
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
| | - Ché Weldon
- Unit for Environmental Sciences and Management, Private Bag x6001, North-West University, Potchefstroom 2520, South Africa
| | - Jaime Bosch
- Museo Nacional de Ciencias Naturales, CSIC c/ Jose Gutierrez Abascal 2, 28006 Madrid, Spain
| | - François Balloux
- UCL Genetics Institute, University College London, London WC1E 6BT, UK
| | - Trenton W J Garner
- Institute of Zoology, Regent's Park, London NW1 4RY, UK
- Unit for Environmental Sciences and Management, Private Bag x6001, North-West University, Potchefstroom 2520, South Africa
- Non-profit Association Zirichiltaggi-Sardinia Wildlife Conservation, Strada Vicinale Filigheddu 62/C, I-07100 Sassari, Italy
| | - Matthew C Fisher
- Department of Infectious Disease Epidemiology and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK.
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16
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Bates KA, Clare FC, O'Hanlon S, Bosch J, Brookes L, Hopkins K, McLaughlin EJ, Daniel O, Garner TWJ, Fisher MC, Harrison XA. Amphibian chytridiomycosis outbreak dynamics are linked with host skin bacterial community structure. Nat Commun 2018; 9:693. [PMID: 29449565 PMCID: PMC5814395 DOI: 10.1038/s41467-018-02967-w] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 01/10/2018] [Indexed: 12/31/2022] Open
Abstract
Host-associated microbes are vital for combatting infections and maintaining health. In amphibians, certain skin-associated bacteria inhibit the fungal pathogen Batrachochytrium dendrobatidis (Bd), yet our understanding of host microbial ecology and its role in disease outbreaks is limited. We sampled skin-associated bacteria and Bd from Pyrenean midwife toad populations exhibiting enzootic or epizootic disease dynamics. We demonstrate that bacterial communities differ between life stages with few shared taxa, indicative of restructuring at metamorphosis. We detected a significant effect of infection history on metamorph skin microbiota, with reduced bacterial diversity in epizootic populations and differences in community structure and predicted function. Genome sequencing of Bd isolates supports a single introduction to the Pyrenees and reveals no association between pathogen genetics and epidemiological trends. Our findings provide an ecologically relevant insight into the microbial ecology of amphibian skin and highlight the relative importance of host microbiota and pathogen genetics in predicting disease outcome. Amphibian skin microbe communities have been putatively associated with the severity of chytrid fungal disease. Here, the authors show that different types of disease dynamics (enzootic versus epizootic) are associated with different microbiota in the host populations.
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Affiliation(s)
- Kieran A Bates
- Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK. .,Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
| | - Frances C Clare
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Simon O'Hanlon
- Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK
| | - Jaime Bosch
- Museo Nacional de Ciencias Naturales, CSIC, Jose Gutierrez Abascal 2, 28006, Madrid, Spain
| | - Lola Brookes
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Emilia J McLaughlin
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Olivia Daniel
- Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK
| | - Trenton W J Garner
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Matthew C Fisher
- Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK
| | - Xavier A Harrison
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
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17
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Sohrabi HR, Bates KA, Weinborn MG, Johnston ANB, Bahramian A, Taddei K, Laws SM, Rodrigues M, Morici M, Howard M, Martins G, Mackay-Sim A, Gandy SE, Martins RN. Olfactory discrimination predicts cognitive decline among community-dwelling older adults. Transl Psychiatry 2012; 2:e118. [PMID: 22832962 PMCID: PMC3365262 DOI: 10.1038/tp.2012.43] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The presence of olfactory dysfunction in individuals at higher risk of Alzheimer's disease has significant diagnostic and screening implications for preventive and ameliorative drug trials. Olfactory threshold, discrimination and identification can be reliably recorded in the early stages of neurodegenerative diseases. The current study has examined the ability of various olfactory functions in predicting cognitive decline in a community-dwelling sample. A group of 308 participants, aged 46-86 years old, were recruited for this study. After 3 years of follow-up, participants were divided into cognitively declined and non-declined groups based on their performance on a neuropsychological battery. Assessment of olfactory functions using the Sniffin' Sticks battery indicated that, contrary to previous findings, olfactory discrimination, but not olfactory identification, significantly predicted subsequent cognitive decline (odds ratio = 0.869; P<0.05; 95% confidence interval = 0.764-0.988). The current study findings confirm previously reported associations between olfactory and cognitive functions, and indicate that impairment in olfactory discrimination can predict future cognitive decline. These findings further our current understanding of the association between cognition and olfaction, and support olfactory assessment in screening those at higher risk of dementia.
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Affiliation(s)
- H R Sohrabi
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia,The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia,The Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia
| | - K A Bates
- The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia,The Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia,The School of Animal Biology, University of Western Australia, Crawley, WA, Australia
| | - M G Weinborn
- The School of Psychology, University of Western Australia, Crawley, WA, Australia
| | - A N B Johnston
- Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, Queensland, Australia
| | - A Bahramian
- The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia
| | - K Taddei
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia,The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia,The Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia
| | - S M Laws
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia,The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia,The Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia
| | - M Rodrigues
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia,The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia
| | - M Morici
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - M Howard
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - G Martins
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia,The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia
| | - A Mackay-Sim
- Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, Queensland, Australia
| | - S E Gandy
- Mount Sinai School of Medicine, New York, NY, USA
| | - R N Martins
- The School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia,The McCusker Alzheimer's Research Foundation, Hollywood Private Hospital, Nedlands, WA, Australia,The Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia,The School of Psychiatry and Clinical Neuroscience, University of Western Australia, Crawley, WA, Australia,The School of Medical Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup, WA 6027, Australia. E-mail:
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18
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Barron AM, Verdile G, Taddei K, Bates KA, Martins RN. Effect of chronic hCG administration on Alzheimer's-related cognition and A beta accumulation in PS1KI mice. Endocrinology 2010; 151:5380-8. [PMID: 20844010 DOI: 10.1210/en.2009-1168] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Age-associated changes in the reproductive hormones-the gonadal steroid hormones and the gonadotropins-have been identified as potential risk factors for Alzheimer's disease (AD). However, levels of gonadotropins and estrogens are closely linked in vivo, and it has proven difficult to separate the effects of gonadotropins from the well-documented estrogenic effects on AD-related neuropathology in experimental models of menopause. To assess the effects of gonadotropins on cognition and AD biochemical markers independent of estrogenic effects, a potent analog of luteinizing hormone [human chorionic gonadotropin (hCG)] was administered to ovariectomized presenilin1 knock-in mice (PS1KI). Gonadotropin administration was found to induce hyperactivity and anxiety (Open Field Maze and Taste Neophobia Task) and working memory dysfunction, without altering reference memory (Morris Water Maze). Although gonadotropin administration modestly altered β amyloid (Aβ40) levels, levels of the longer more toxic form (Aβ42) were unaffected. Furthermore, altered Aβ40 levels were not associated with observed behavioral and cognitive impairments. These findings provide proof, in principle, that the gonadotropin hormones play a role in the modulation of AD-related behavior, cognition, and neuropathology.
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Affiliation(s)
- A M Barron
- School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Nedlands, 6009, Australia
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19
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Abstract
The relationship between menopause and cognitive decline has been the subject of intense research since a number of studies have shown that hormone replacement therapy could reduce the risk of developing Alzheimer's disease in women. In contrast, research into andropause has only recently begun. Furthermore, evidence now suggests that steroidogenesis is not restricted to the gonads and adrenals, and that the brain is capable of producing its own steroid hormones, including testosterone and estrogen. Sex hormones have been demonstrated to be of critical importance in the embryonic development of the central nervous system (CNS); however, we are only just beginning to understand the role that these hormones may play in the normal functioning and repair of the adult mammalian CNS. This review will summarize current research into the role of androgens and andropause on cognition and the possible mechanisms of action of androgens, with particular reference to Alzheimer's disease.
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Affiliation(s)
- K A Bates
- School of Anatomy and Human Biology, the University of Western Australia, 35 Stirling Hwy Crawley, Western Australia 6009, Australia
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20
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Abstract
Alzheimer's disease is a progressively dementing illness characterized by the extracellular accumulation and deposition of beta-amyloid. Early onset Alzheimer's disease is linked to mutations in three genes, all of which lead to increased beta-amyloid production. Inflammatory changes and gliosis may also play a role in the disease process, but the importance of these reactive events remains unclear. We recently reported that chronic cortical gliosis in heterotopic fetal rat cortical transplants is associated with significant changes in the levels of some of the proteins implicated in the pathogenesis of Alzheimer's disease. Because rodent beta-amyloid does not form extracellular amyloid deposits, we have now extended this model of chronic cortical gliosis to transgenic mice expressing the Swedish mutant form of human amyloid precursor protein. In addition, apolipoprotein E knockout mice were used to elucidate the role of this protein in reactive gliosis. The expression of mutant and murine proteins was assayed 6 or 10 months after transplantation using immunohistochemical and western blot methods. Heterotopic transplantation of fetal cortex onto the midbrain of neonatal mice consistently resulted in reactive gliosis, independent of apolipoprotein E status. In contrast, in homotopic cortex-to-cortex grafts there was little alteration in glial reactivity, a result similar to that obtained previously in rats. By 10 months post-transplantation the level of presenilin-1 expression was lower in heterotopic grafts than in host cortex and there was increased expression of transgenic amyloid precursor protein, but only in the gliotic cortex-to-midbrain grafts. Most importantly, increased levels of beta-amyloid, and particularly its precursor, C-99, were selectively found in these heterotopic transplants. Our results show that chronic gliosis is associated with altered processing of the amyloid precursor protein in vivo and thus may initiate or exacerbate pathological changes associated with Alzheimer's disease.
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Affiliation(s)
- K A Bates
- School of Anatomy and Human Biology, The University of Western Australia, Nedlands, WA 6009, Australia
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21
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Martins RN, Taddei K, Kendall C, Evin G, Bates KA, Harvey AR. Altered expression of apolipoprotein E, amyloid precursor protein and presenilin-1 is associated with chronic reactive gliosis in rat cortical tissue. Neuroscience 2002; 106:557-69. [PMID: 11591456 DOI: 10.1016/s0306-4522(01)00289-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A major characteristic feature of Alzheimer's disease is the formation of compact, extracellular deposits of beta-amyloid (senile plaques). These deposits are surrounded by reactive astrocytes, microglia and dystrophic neurites. Mutations in three genes have been implicated in early-onset familial Alzheimer's disease. However, inflammatory changes and astrogliosis are also believed to play a role in Alzheimer's pathology. What is unclear is the extent to which these factors initiate or contribute to the disease progression. Previous rat studies demonstrated that heterotopic transplantation of foetal cortical tissue onto the midbrain of neonatal hosts resulted in sustained glial reactivity for many months. Similar changes were not seen in cortex-to-cortex grafts. Using this model of chronic cortical gliosis, we have now measured reactive changes in the levels of the key Alzheimer's disease proteins, namely the amyloid precursor protein, apolipoprotein E and presenilin-1. These changes were visualised immunohistochemically and were quantified by western blot analysis. We report here that chronic cortical gliosis in the rat results in a sustained increase in the levels of apolipoprotein E and total amyloid precursor protein. Reactive astrocytes in heterotopic cortical grafts were immunopositive for both of these proteins. Using a panel of amyloid precursor protein antibodies we demonstrate that chronic reactive gliosis is associated with alternative cleavage of the peptide. No significant changes in apolipoprotein E or amyloid precursor protein expression were seen in non-gliotic cortex-to-cortex transplants. Compared to host cortex, the levels of both N-terminal and C-terminal fragments of presenilin-1 were significantly lower in gliotic heterotopic grafts.The changes described here largely mirror those seen in the cerebral cortex of humans with Alzheimer's disease and are consistent with the proposal that astrogliosis may be an important factor in the pathogenesis of this disease.
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Affiliation(s)
- R N Martins
- Sir James McCusker Alzheimer Research Unit and University Department of Surgery, The University of Western Australia, Nedlands, Austalia.
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Roncone RL, Li L, Bates KA, Burke JJ, Weisenbach L, Zelinski BJ. Design and fabrication of a single leakage-channel grating coupler. Appl Opt 1993; 32:4522-4528. [PMID: 20830114 DOI: 10.1364/ao.32.004522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We describe the modeling and fabrication of waveguide grating couplers with theoretical outcoupling efficiencies into a single diffracted order nearing 100%. Termed single leakage-channel grating couplers (or SLCGC's), these devices utilize a high-reflectivity dielectric stack to reflect the outcoupled beam diffracted toward the substrate and back up into the air region, where it constructively adds with the beam diffracted into the air region. Computer modeling shows that the branching ratio and the leakage rate can be independently controlled, and that the branching ratio is independent of grating depth and grating period. A SLCGC with a branching ratio of 97.1% is fabricated by the use of a combination of vacuum-evaporation and wet-chemical techniques.
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Bates KA, Li L, Roncone RL, Burke JJ. Gaussian beams from variable groove depth grating couplers in planar waveguides. Appl Opt 1993; 32:2112-2116. [PMID: 20820355 DOI: 10.1364/ao.32.002112] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Analysis, fabrication, and characterization of variable groove depth planar waveguide grating couplers are presented. A formula is derived to describe the grating groove depth variation necessary to produce an outcoupled beam of arbitrary profile. A variable depth grating for producing a Gaussian beam profile is fabricated on a waveguide by ion-beam etching through a scanning slit apparatus. A photoresist grating placed on the waveguide provides a mask to define the grating etched onto the waveguide. The near-field irradiance of the outcoupled beam is measured and shown to approach a Gaussian profile.
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