1
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McMinds R, Jiang RHY, Adapa SR, Cornelius Ruhs E, Munds RA, Leiding JW, Downs CJ, Martin LB. Bacterial sepsis triggers stronger transcriptomic immune responses in larger primates. Proc Biol Sci 2024; 291:20240535. [PMID: 38917861 DOI: 10.1098/rspb.2024.0535] [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: 08/15/2023] [Accepted: 04/05/2024] [Indexed: 06/27/2024] Open
Abstract
Empirical data relating body mass to immune defence against infections remain limited. Although the metabolic theory of ecology predicts that larger organisms would have weaker immune responses, recent studies have suggested that the opposite may be true. These discoveries have led to the safety factor hypothesis, which proposes that larger organisms have evolved stronger immune defences because they carry greater risks of exposure to pathogens and parasites. In this study, we simulated sepsis by exposing blood from nine primate species to a bacterial lipopolysaccharide (LPS), measured the relative expression of immune and other genes using RNAseq, and fitted phylogenetic models to determine how gene expression was related to body mass. In contrast to non-immune-annotated genes, we discovered hypermetric scaling in the LPS-induced expression of innate immune genes, such that large primates had a disproportionately greater increase in gene expression of immune genes compared to small primates. Hypermetric immune gene expression appears to support the safety factor hypothesis, though this pattern may represent a balanced evolutionary mechanism to compensate for lower per-transcript immunological effectiveness. This study contributes to the growing body of immune allometry research, highlighting its importance in understanding the complex interplay between body size and immunity over evolutionary timescales.
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Affiliation(s)
- Ryan McMinds
- Center for Global Health and Infectious Diseases Research (GHIDR), University of South Florida , Tampa, FL, USA
- USF Genomics Program, University of South Florida College of Public Health , Tampa, FL, USA
| | - Rays H Y Jiang
- Center for Global Health and Infectious Diseases Research (GHIDR), University of South Florida , Tampa, FL, USA
- USF Genomics Program, University of South Florida College of Public Health , Tampa, FL, USA
| | - Swamy R Adapa
- Center for Global Health and Infectious Diseases Research (GHIDR), University of South Florida , Tampa, FL, USA
- USF Genomics Program, University of South Florida College of Public Health , Tampa, FL, USA
| | - Emily Cornelius Ruhs
- Center for Global Health and Infectious Diseases Research (GHIDR), University of South Florida , Tampa, FL, USA
- Department of Ecology and Evolution, University of Chicago , Chicago, IL, USA
- Grainger Bioinformatics Center, Field Museum of Natural History , Chicago, IL, USA
| | - Rachel A Munds
- Center for Global Health and Infectious Diseases Research (GHIDR), University of South Florida , Tampa, FL, USA
| | - Jennifer W Leiding
- Division of Allergy and Immunology, Department of Pediatrics, Johns Hopkins Medicine , St Petersburg, FL, USA
- Institute for Clinical and Translational Research, Johns Hopkins All Children's Hospital , St Petersburg, FL, USA
| | - Cynthia J Downs
- Department of Environmental Biology, SUNY College of Environmental Science and Forestry , Syracuse, NY, USA
| | - Lynn B Martin
- Center for Global Health and Infectious Diseases Research (GHIDR), University of South Florida , Tampa, FL, USA
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2
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Xiao Y, Liu X, Song Z, Lu Y, Zhang L, Huang M, Cheng Y, Chen S, Zhao Y, Zhang Z, Zhou S. Plant size-dependent influence of foliar fungal pathogens promotes diversity through allometric growth. THE NEW PHYTOLOGIST 2024; 242:687-699. [PMID: 38396376 DOI: 10.1111/nph.19600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 01/26/2024] [Indexed: 02/25/2024]
Abstract
The effect of pathogens on host diversity has attracted much attention in recent years, yet how the influence of pathogens on individual plants scales up to affect community-level host diversity remains unclear. Here, we assessed the effects of foliar fungal pathogens on plant growth and species richness using allometric growth theory in population-level and community-level foliar fungal pathogen exclusion experiments. We calculated growth scaling exponents of 24 species to reveal the intraspecific size-dependent effects of foliar fungal pathogens on plant growth. We also calculated the intercepts to infer the growth rates of relatively larger conspecific individuals. We found that foliar fungal pathogens inhibited the growth of small conspecific individuals more than large individuals, resulting in a positive allometric growth. After foliar fungal pathogen exclusion, species-specific growth scaling exponents and intercepts decreased, but became positively related to species' relative abundance, providing a growth advantage for individuals of abundant species with a higher growth scaling exponent and intercept compared with rare species, and thus reduced species diversity. By adopting allometric growth theory, we elucidate the size-dependent mechanisms through which pathogens regulate species diversity and provide a powerful framework to incorporate antagonistic size-dependent processes in understanding species coexistence.
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Affiliation(s)
- Yao Xiao
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, China
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Xiang Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Zhiping Song
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, China
| | - Yawen Lu
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, China
| | - Li Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, China
| | - Mengjiao Huang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, China
| | - Yikang Cheng
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, China
| | - Shiliang Chen
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, China
| | - Yimin Zhao
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, 570228, China
| | - Zhenhua Zhang
- Qinghai Haibei National Field Research Station of Alpine Grassland Ecosystem, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, China
| | - Shurong Zhou
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, 570228, China
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3
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Huang ZYX, Halliday FW, Becker DJ. Host functional traits as the nexus for multilevel infection patterns. Trends Ecol Evol 2023; 38:1125-1128. [PMID: 37684132 DOI: 10.1016/j.tree.2023.08.011] [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: 06/01/2023] [Revised: 07/27/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023]
Abstract
Understanding pathogen transmission and infection patterns at multiple biological scales is a central issue in disease ecology and evolution. Here, we suggest that functional traits of host species readily affect infection patterns of species, communities, and landscapes, and thus serve as a linkage for multilevel studies of infectious disease.
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Affiliation(s)
- Zheng Y X Huang
- School of Life Sciences, Nanjing Normal University, 210023 Nanjing, Jiangsu, China.
| | - Fletcher W Halliday
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland; Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA.
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4
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Ramírez-Otarola N, Maldonado K, Valdés-Ferranty F, Newsome SD, Sabat P. Seasonal changes in diet, immune function, and oxidative stress in three passerines inhabiting a Mediterranean climate. Oecologia 2023; 203:395-405. [PMID: 37950102 DOI: 10.1007/s00442-023-05474-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023]
Abstract
Oxidative status and immune function are energy-demanding traits closely linked to diet composition, particularly resource availability and nutritional value. In seasonal environments, nutrient availability and diet quality fluctuate, potentially influencing these traits. However, limited evidence exists regarding these dietary effects on immune function in seasonal environments. In this study, we employed stable isotope analysis to assess the impact of seasonal changes in niche width and trophic level (i.e., δ15N) on two immune variables (hemolysis and hemagglutination scores) and two oxidative status parameters (lipid peroxidation and total antioxidant capacity) in three passerine species: Zonotrichia capensis (omnivorous), Troglodytes aedon (insectivorous), and Spinus barbatus (granivorous). We found that hemolysis scores varied seasonally in Z. capensis, with higher values in winter compared to summer. Total antioxidant capacity (TAC) also increased during the winter in Z. capensis and S. barbatus. The isotopic niche width for Z. capensis and S. barbatus was smaller in winter than in summer, with the omnivorous species exhibiting a decrease in δ15N. Despite the seasonal shifts in ecological and physiological traits in Z. capensis, we identified no correlation between immune response and TAC with trophic level. In contrast, in the granivorous S. barbatus, the lower trophic level resulted in an increase in TAC without affecting immunity. Our findings revealed that dietary shifts do not uniformly impact oxidative status and immune function across bird species, highlighting species-specific responses to seasonal changes. This underscores the importance of integrating ecological and evolutionary perspectives when examining how diet shapes avian immunity and oxidative balance.
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Affiliation(s)
- Natalia Ramírez-Otarola
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino La Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Karin Maldonado
- Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago, Chile
| | - Fernanda Valdés-Ferranty
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Seth D Newsome
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Pablo Sabat
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
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5
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Fletcher LE, Martin LB, Downs CJ. Leukocyte Concentrations Are Isometric in Reptiles Unlike in Endotherms. Physiol Biochem Zool 2023; 96:405-417. [PMID: 38237194 DOI: 10.1086/727050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
AbstractHow do large and small reptiles defend against infections, given the consequences of body mass for physiology and disease transmission? Functionally equivalent mammalian and avian granulocytes increased disproportionately with body mass (i.e., scaled hypermetrically), such that large organisms had higher concentrations than expected by a prediction of proportional protection across sizes. However, as these scaling relationships were derived from endothermic animals, they do not necessarily inform the scaling of leukocyte concentration for ectothermic reptiles that have a different physiology and evolutionary history. Here, we asked whether and how lymphocyte and heterophil concentrations relate to body mass among more than 120 reptile species. We compared these relationships to those found in birds and mammals and to existing scaling frameworks (i.e., protecton, complexity, rate of metabolism, or safety factor hypotheses). Both lymphocyte and heterophil concentrations scaled almost isometrically among reptiles. In contrast, functionally equivalent granulocytes scaled hypermetrically and lymphocytes scaled isometrically in birds and mammals. Life history traits were also poor predictors of variation in reptilian heterophil and lymphocyte concentrations. Our results provide insight into differences in immune protection in birds and mammals relative to that in reptiles through a comparative lens. The shape of scaling relationships differs, which should be considered when modeling disease dynamics among these groups.
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6
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Yin S, Li N, Xu W, Becker DJ, de Boer WF, Xu C, Mundkur T, Fountain-Jones NM, Li C, Han GZ, Wu Q, Prosser DJ, Cui L, Huang ZYX. Functional traits explain waterbirds' host status, subtype richness, and community-level infection risk for avian influenza. Ecol Lett 2023; 26:1780-1791. [PMID: 37586885 DOI: 10.1111/ele.14294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/17/2023] [Indexed: 08/18/2023]
Abstract
Species functional traits can influence pathogen transmission processes, and consequently affect species' host status, pathogen diversity, and community-level infection risk. We here investigated, for 143 European waterbird species, effects of functional traits on host status and pathogen diversity (subtype richness) for avian influenza virus at species level. We then explored the association between functional diversity and HPAI H5Nx occurrence at the community level for 2016/17 and 2021/22 epidemics in Europe. We found that both host status and subtype richness were shaped by several traits, such as diet guild and dispersal ability, and that the community-weighted means of these traits were also correlated with community-level risk of H5Nx occurrence. Moreover, functional divergence was negatively associated with H5Nx occurrence, indicating that functional diversity can reduce infection risk. Our findings highlight the value of integrating trait-based ecology into the framework of diversity-disease relationship, and provide new insights for HPAI prediction and prevention.
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Affiliation(s)
- Shenglai Yin
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ning Li
- Institute of Applied Ecology, Nanjing Xiaozhuang University, Nanjing, China
| | - Wenjie Xu
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, Oklahoma, USA
| | - Willem F de Boer
- Wildlife Ecology and Conservation Group, Wageningen University, Wageningen, The Netherlands
| | - Chi Xu
- School of Life Sciences, Nanjing University, Nanjing, China
| | - Taej Mundkur
- Wetlands International, Ede, The Netherlands
- Good Earth Environmental, Arnhem, The Netherlands
| | | | - Chunlin Li
- School of Resources and Environmental Engineering, Anhui University, Hefei, China
| | - Guan-Zhu Han
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qiang Wu
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Diann J Prosser
- Eastern Ecological Science Center, United States Geological Survey, Laurel, Maryland, USA
| | - Lijuan Cui
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Zheng Y X Huang
- College of Life Sciences, Nanjing Normal University, Nanjing, China
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7
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Combs MA, Tufts DM, Adams B, Lin YP, Kolokotronis SO, Diuk-Wasser MA. Host adaptation drives genetic diversity in a vector-borne disease system. PNAS NEXUS 2023; 2:pgad234. [PMID: 37559749 PMCID: PMC10408703 DOI: 10.1093/pnasnexus/pgad234] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/18/2023] [Accepted: 07/07/2023] [Indexed: 08/11/2023]
Abstract
The range of hosts a pathogen can infect is a key trait, influencing human disease risk and reservoir host infection dynamics. Borrelia burgdorferi sensu stricto (Bb), an emerging zoonotic pathogen, causes Lyme disease and is widely considered a host generalist, commonly infecting mammals and birds. Yet the extent of intraspecific variation in Bb host breadth, its role in determining host competence, and potential implications for human infection remain unclear. We conducted a long-term study of Bb diversity, defined by the polymorphic ospC locus, across white-footed mice, passerine birds, and tick vectors, leveraging long-read amplicon sequencing. Our results reveal strong variation in host breadth across Bb genotypes, exposing a spectrum of genotype-specific host-adapted phenotypes. We found support for multiple niche polymorphism, maintaining Bb diversity in nature and little evidence of temporal shifts in genotype dominance, as would be expected under negative frequency-dependent selection. Passerine birds support the circulation of several human-invasive strains (HISs) in the local tick population and harbor greater Bb genotypic diversity compared with white-footed mice. Mouse-adapted Bb genotypes exhibited longer persistence in individual mice compared with nonadapted genotypes. Genotype communities infecting individual mice preferentially became dominated by mouse-adapted genotypes over time. We posit that intraspecific variation in Bb host breadth and adaptation helps maintain overall species fitness in response to transmission by a generalist vector.
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Affiliation(s)
- Matthew A Combs
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
- Department of Epidemiology and Biostatistics, School of Public Health, SUNY Downstate Health Sciences University, Brooklyn, NY 11203-2098, USA
- Institute for Genomics in Health, SUNY Downstate Health Sciences University, Brooklyn, NY 11203-2098, USA
| | - Danielle M Tufts
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
- Infectious Diseases and Microbiology Department, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Ben Adams
- Department of Mathematical Sciences, University of Bath, Bath, BA27AY, UK
| | - Yi-Pin Lin
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
- Department of Biomedical Sciences, University at Albany, Albany, NY 12203, USA
| | - Sergios-Orestis Kolokotronis
- Department of Epidemiology and Biostatistics, School of Public Health, SUNY Downstate Health Sciences University, Brooklyn, NY 11203-2098, USA
- Institute for Genomics in Health, SUNY Downstate Health Sciences University, Brooklyn, NY 11203-2098, USA
- Division of Infectious Diseases, Department of Medicine, College of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY 11203-2098, USA
- Department of Cell Biology, College of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY 11203-2098, USA
| | - Maria A Diuk-Wasser
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
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8
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Douchet P, Gourbal B, Loker ES, Rey O. Schistosoma transmission: scaling-up competence from hosts to ecosystems. Trends Parasitol 2023; 39:563-574. [PMID: 37120369 PMCID: PMC10880732 DOI: 10.1016/j.pt.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/28/2023] [Accepted: 04/04/2023] [Indexed: 05/01/2023]
Abstract
In a One-Health context, it is urgent to establish the links between environmental degradation, biodiversity loss, and the circulation of pathogens. Here we review and literally draw a general vision of aquatic environmental factors that interface with Schistosoma species, agents of schistosomiasis, and ultimately modulate their transmission at the ecosystem scale. From this synthesis, we introduce the concept of ecosystem competence defined as 'the propensity of an ecosystem to amplify or mitigate an incoming quantity of a given pathogen that can be ultimately transmitted to their definitive hosts'. Ecosystem competence integrates all mechanisms at the ecosystem scale underlying the transmission risk of a given pathogen and offers a promising measure for operationalizing the One-Health concept.
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Affiliation(s)
- Philippe Douchet
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France
| | - Benjamin Gourbal
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France
| | - Eric S Loker
- Center for Evolutionary and Theoretical Immunology (CETI), Parasite Division - Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Olivier Rey
- IHPE, Univ Montpellier, CNRS, IFREMER, Univ Perpignan Via Domitia, Perpignan, France.
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9
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Clement MJ, Justice-Allen A, Heale JD. Optimal risk-based allocation of disease surveillance effort for clustered disease outbreaks. Prev Vet Med 2023; 212:105830. [PMID: 36657356 DOI: 10.1016/j.prevetmed.2022.105830] [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: 06/30/2022] [Revised: 12/19/2022] [Accepted: 12/22/2022] [Indexed: 01/07/2023]
Abstract
Designing a disease surveillance program to detect a disease is challenging when animals are organized into herds, in part because disease cases are likely to be clustered. Clustered diseases are often surveilled using two-stage sampling, which allocates tests both among herds and within herds. Finding the optimal allocation of tests is computationally difficult, so some surveillance programs simply seek an approximate solution. We developed a search algorithm to find the optimal allocation of tests by iteratively searching for adjustments to the test allocation that yielded marginal improvements in system sensitivity. We digitally generated 21 herds of various sizes, evenly divided among three regions that differed in relative risk. We then analyzed 29 scenarios that differed in disease and testing characteristics. We also analyzed a Chronic Wasting Disease (CWD) surveillance effort for 23 elk game management units of various sizes that were spread across three regions in Arizona, USA. We compared our marginal sensitivity approach to two other strategies for approximating the optimal distribution of tests: allocating the same number of tests to all herds selected for testing, and allocating tests so that all herds selected for testing achieve the same sensitivity. Across analysis scenarios, we found that low prevalence, high relative risk, a small budget, or high overhead costs were best addressed by concentrating tests in large, high-risk herds. When we expect multiple herds to be infected, the optimal allocation of tests depended on how we expected the cases to be distributed. Across the analyzed scenarios, our marginal sensitivity approach was most efficient, with alternative strategies requiring 0-228 % more tests to achieve the same sensitivity. For CWD in Arizona, we found the potential to double system sensitivity, given a population design prevalence of 0.16 %, from 35.8 % to 70.5 %, although social and budgetary considerations would likely constrain changes to the current allocation of tests. The marginal sensitivity approach we developed has the potential to improve disease surveillance, especially when a population includes a limited number of herds that differ in size. An important limitation of our approach is that computer runtimes could become unacceptably long for a population with many herds.
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Affiliation(s)
- Matthew J Clement
- Arizona Game and Fish Department, 5000 W. Carefree Highway, Phoenix, AZ 85086, USA.
| | - Anne Justice-Allen
- Arizona Game and Fish Department, 5000 W. Carefree Highway, Phoenix, AZ 85086, USA
| | - Jonathon D Heale
- Arizona Game and Fish Department, 5000 W. Carefree Highway, Phoenix, AZ 85086, USA
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10
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Simonis MC, Hartzler LK, Turner GG, Scafini MR, Johnson JS, Rúa MA. Long‐term exposure to an invasive fungal pathogen decreases
Eptesicus fuscus
body mass with increasing latitude. Ecosphere 2023. [DOI: 10.1002/ecs2.4426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Affiliation(s)
- Molly C. Simonis
- Department of Biology University of Oklahoma Norman Oklahoma USA
- Environmental Sciences PhD Program Wright State University Dayton Ohio USA
| | - Lynn K. Hartzler
- Environmental Sciences PhD Program Wright State University Dayton Ohio USA
- Department of Biological Sciences Wright State University Dayton Ohio USA
| | - Gregory G. Turner
- Bureau of Wildlife Management Pennsylvania Game Commission Harrisburg Pennsylvania USA
| | - Michael R. Scafini
- Bureau of Wildlife Management Pennsylvania Game Commission Harrisburg Pennsylvania USA
| | - Joseph S. Johnson
- School of Information Technology University of Cincinnati Cincinnati Ohio USA
| | - Megan A. Rúa
- Environmental Sciences PhD Program Wright State University Dayton Ohio USA
- Department of Biological Sciences Wright State University Dayton Ohio USA
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11
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Downs CJ, Schoenle LA, Goolsby EW, Oakey SJ, Ball R, Jiang RHY, Martin LB. Large Mammals Have More Powerful Antibacterial Defenses Than Expected from Their Metabolic Rates. Am Nat 2023; 201:287-301. [PMID: 36724463 DOI: 10.1086/722504] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
AbstractTerrestrial mammals span seven orders of magnitude in body size, ranging from the <2-g Etruscan pygmy shrew (Suncus etruscus) to the >3,900-kg African elephant (Loxodonta africana). Although body size profoundly affects the behavior, physiology, ecology, and evolution of species, how investment in functional immune defenses changes with body size across species is unknown. Here, we (1) developed a novel 12-point dilution curve approach to describe and compare antibacterial capacity against three bacterial species among >160 terrestrial species of mammals and (2) tested published predictions about the scaling of immune defenses. Our study focused on the safety factor hypothesis, which predicts that broad, early-acting immune defenses should scale hypermetrically with body mass. However, our three statistical approaches demonstrated that antibacterial activity in sera across mammals exhibits isometry; killing capacity did not change with body size across species. Intriguingly, this result indicates that the serum of a large mammal is less hospitable to bacteria than would be predicted by its metabolic rates. In other words, if metabolic rates underlie the rates of physiological reactions as postulated by the metabolic theory of ecology, large species should have disproportionately lower antibacterial capacity than small species, but they do not. These results have direct implications for effectively modeling the evolution of immune defenses and identifying potential reservoir hosts of pathogens.
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12
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Chen L, Kong P, Hou L, Zhou Y, Zhou L. Host community composition, community assembly pattern, and disease transmission mode jointly determine the direction and strength of the diversity-disease relationship. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1032931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rapid global biodiversity loss and increasing emerging infectious diseases underscore the significance of identifying the diversity-disease relationship. Although experimental evidence supports the existence of dilution effects in several natural ecosystems, we still know very little about the conditions under which a dilution effect will occur. Using a multi-host Susceptible-Infected-Recovered model, we found when disease transmission was density-dependent, the diversity-disease relationship could exhibit an increasing, decreasing, or non-monotonic trend, which mainly depended on the patterns of community assembly. However, the combined effects of the host competence-abundance relationship and species extinction order may reverse or weaken this trend. In contrast, when disease transmission was frequency-dependent, the diversity-disease relationship only showed a decreasing trend, the host competence-abundance relationship and species extinction order did not alter this decreasing trend, but it could reduce the detectability of the dilution effect and affect disease prevalence. Overall, a combination of disease transmission mode, community assembly pattern, and host community composition determines the direction or strength of the diversity-disease relationship. Our work helps explain why previous studies came to different conclusions about the diversity-disease relationship and provides a deeper understanding of the pathogen transmission dynamics in actual communities.
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13
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Walsh MG, Pattanaik A, Vyas N, Saxena D, Webb C, Sawleshwarkar S, Mukhopadhyay C. A biogeographical description of the wild waterbird species associated with high-risk landscapes of Japanese encephalitis virus in India. Transbound Emerg Dis 2022; 69:e3015-e3023. [PMID: 35809085 PMCID: PMC9796264 DOI: 10.1111/tbed.14656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 01/01/2023]
Abstract
Wild reservoirs of Japanese encephalitis virus are under-studied globally, which presents critical knowledge gaps for JEV epidemiology and infection ecology despite decades of received wisdom regarding this high-impact mosquito-borne virus. As a result, ardeid birds, generally understood to be the primary reservoirs for JEV, as well as other waterbirds occupying landscapes at high risk for spillover to humans, are frequently ignored by current surveillance mechanisms and infrastructure. This is particularly true in India, which experiences a high annual burden of human outbreaks. Incorporating wild reservoirs into surveillance of human and livestock populations is therefore essential but will first require a data-driven approach to target individual host species. The current study sought to identify preliminary waterbird target species for JEV surveillance development based on species' distributions in high-risk landscapes. Twenty-one target species were identified after adjusting species presence and abundance for the biotic constraints of sympatry. Furthermore, ardeid bird species richness demonstrated a strong non-linear association with the distribution of human JEV outbreaks, which suggested areas with the highest ardeid species richness corresponded to low JEV outbreak risk. No association was identified between JEV outbreaks and anatid or rallid richness. The lack of association between Anatidae and Rallidae family-level diversity and JEV outbreak risk notwithstanding, this study did identify several individual species among these two bird families in high-risk landscapes. The findings from this work provide the first data-driven evidence base to inform wildlife sampling for the monitoring of JEV circulation in outbreak hotspots in India and thus identify good preliminary targets for the development of One Health JEV surveillance.
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Affiliation(s)
- Michael G. Walsh
- Faculty of Medicine and Health, School of Public HealthThe University of SydneyCamperdownNew South WalesAustralia,Faculty of Medicine and Health, Sydney Institute for Infectious DiseasesThe University of SydneyWestmeadNew South WalesAustralia,One Health Centre, The Prasanna School of Public HealthManipal Academy of Higher EducationManipalKarnatakaIndia,The Prasanna School of Public HealthManipal Academy of Higher EducationManipalKarnatakaIndia
| | - Amrita Pattanaik
- Manipal Institute of VirologyManipal Academy of Higher EducationManipalKarnatakaIndia
| | - Navya Vyas
- One Health Centre, The Prasanna School of Public HealthManipal Academy of Higher EducationManipalKarnatakaIndia,The Prasanna School of Public HealthManipal Academy of Higher EducationManipalKarnatakaIndia
| | - Deepak Saxena
- Department of EpidemiologyIndian Institute of Public Health GandhinagarGandhinagarGujaratIndia
| | - Cameron Webb
- Faculty of Medicine and Health, Sydney Institute for Infectious DiseasesThe University of SydneyWestmeadNew South WalesAustralia,Department of Medical EntomologyNSW Health Pathology, Westmead HospitalWestmeadNew South WalesAustralia
| | - Shailendra Sawleshwarkar
- Faculty of Medicine and Health, Sydney Institute for Infectious DiseasesThe University of SydneyWestmeadNew South WalesAustralia,One Health Centre, The Prasanna School of Public HealthManipal Academy of Higher EducationManipalKarnatakaIndia,The Prasanna School of Public HealthManipal Academy of Higher EducationManipalKarnatakaIndia,Faculty of Medicine and Health, Westmead Clinical SchoolThe University of SydneyWestmeadNew South WalesAustralia
| | - Chiranjay Mukhopadhyay
- Department of Microbiology, Kasturba Medical CollegeManipal Academy of Higher EducationManipalKarnatakaIndia,Centre for Emerging and Tropical Diseases, Kasturba Medical CollegeManipal Academy of Higher EducationManipalKarnatakaIndia
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14
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Martin LB, Ruhs EC, Oakey S, Downs CJ. Leukocyte allometries in birds are not affected by captivity. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:576-582. [PMID: 35286769 DOI: 10.1002/jez.2591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/17/2022] [Accepted: 02/11/2022] [Indexed: 12/15/2022]
Abstract
Body size affects many traits, but often in allometric, or disproportionate ways. For example, large avian and mammalian species circulate far more of some immune cells than expected for their size based on simple geometric principles. To date, such hypermetric immune scaling has mostly been described in zoo-dwelling individuals, so it remains obscure whether immune hyper-allometries have any natural relevance. Here, we asked whether granulocyte and lymphocyte allometries in wild birds differ from those described in captive species. Our previous allometric studies of avian immune cell concentrations were performed on animals kept for their lifetimes in captivity where conditions are benign and fairly consistent. In natural conditions, infection, stress, nutrition, climate, and myriad other forces could alter immune traits and hence mask any interspecific scaling relationships between immune cells and body size. Counter to this expectation, we found no evidence that immune cell allometries differed between captive and wild species, although we had to rely on cell proportion data, as insufficient concentration data were available for wild species. Our results indicate that even in variable and challenging natural contexts, immune allometries endure and might affect disease ecology and evolution.
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Affiliation(s)
- Lynn B Martin
- Global Health and Infectious Disease Research, University of South Florida, Tampa, Florida, USA
| | - Emily Cornelius Ruhs
- Global Health and Infectious Disease Research, University of South Florida, Tampa, Florida, USA
| | - Samantha Oakey
- Global Health and Infectious Disease Research, University of South Florida, Tampa, Florida, USA
| | - Cynthia J Downs
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, Syracuse, New York, USA
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15
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Stewart Merrill TE, Calhoun DM, Johnson PTJ. Beyond single host, single parasite interactions: quantifying competence for complete multi‐host, multi‐parasite communities. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14068] [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)
- Tara E. Stewart Merrill
- Coastal & Marine Lab Florida State University St. Teresa, 32358 FL
- Ecology and Evolutionary Biology University of Colorado Boulder Boulder, 80309 CO
| | - Dana M. Calhoun
- Ecology and Evolutionary Biology University of Colorado Boulder Boulder, 80309 CO
| | - Pieter T. J. Johnson
- Ecology and Evolutionary Biology University of Colorado Boulder Boulder, 80309 CO
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16
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Affiliation(s)
- Amy R. Sweeny
- Institute of Evolutionary Biology University of Edinburgh Edinburgh Scotland
| | - Gregory F. Albery
- Department of Biology Georgetown University Washington DC USA
- Wissenschaftskolleg zu Berlin Berlin Germany
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17
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Claunch NM, Bartoszek IA, Tillis S, Stacy NI, Ossiboff RJ, Oakey S, Schoenle LA, Wellehan JFX, Romagosa CM. Physiological effects of capture and short-term captivity in an invasive snake species, the Burmese python (Python bivittatus) in Florida. Comp Biochem Physiol A Mol Integr Physiol 2022; 267:111162. [PMID: 35149178 DOI: 10.1016/j.cbpa.2022.111162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/04/2022] [Accepted: 02/04/2022] [Indexed: 02/05/2023]
Abstract
It is important to evaluate the role of captivity as a potential stressor. An understanding of stress responses to capture and transition to captivity may inform the limitations of laboratory studies on wild animals, aid in understanding the consequences of introducing animals into captive environments, and help predict which species may be successful invasives. We investigated physiological effects of captivity by comparing at-capture blood variables in wild Burmese pythons (Python bivittatus) in Florida to pythons recently brought into captivity (1-109 days). We conducted an acute restraint test by collecting samples at baseline (immediately at handling) and one hour post-restraint across wild field-sampled (n = 19) and recently-captive (n = 33) pythons to evaluate fluctuations in plasma corticosterone, bacterial killing ability, antibody response, leukogram, and serpentovirus infection. We observed higher baseline plasma corticosterone and monocytes in recently captive compared to wild snakes, which both subsided in snakes held for a longer time in captivity, and a mild decrease in lymphocytes in the middle of the captivity period. Functional immunity and viral infection were not affected by captivity, and pythons maintained restraint-induced responses in corticosterone, heterophil to lymphocyte ratio, and monocyte counts throughout captivity. Prevalence for serpentovirus was 50%, though infection status was related to sampling date rather than captivity, indicating that viral infection may be seasonal. The history of Burmese python as a common captive animal for research and pet trade, as well as its general resilience to effects of capture and short-term captivity, may contribute to its invasion success in Florida.
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Affiliation(s)
- Natalie M Claunch
- School of Natural Resources and Environment, University of Florida, USA.
| | | | - Steve Tillis
- College of Veterinary Medicine, University of Florida, USA
| | - Nicole I Stacy
- College of Veterinary Medicine, University of Florida, USA
| | | | - Samantha Oakey
- College of Veterinary Medicine, University of Georgia, USA
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18
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Grunberg RL, Anderson DM. Host Energetics Explain Variation in Parasite Productivity across Hosts and Ecosystems. Am Nat 2021; 199:266-276. [DOI: 10.1086/717430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Rita L. Grunberg
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, New Jersey 08901
| | - David M. Anderson
- Department of Biology, University of Florida, Gainesville, Florida 32611
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19
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Wang YXG, Matson KD, Santini L, Visconti P, Hilbers JP, Huijbregts MAJ, Xu Y, Prins HHT, Allen T, Huang ZYX, de Boer WF. Mammal assemblage composition predicts global patterns in emerging infectious disease risk. GLOBAL CHANGE BIOLOGY 2021; 27:4995-5007. [PMID: 34214237 PMCID: PMC8518613 DOI: 10.1111/gcb.15784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 06/13/2021] [Accepted: 06/13/2021] [Indexed: 06/13/2023]
Abstract
As a source of emerging infectious diseases, wildlife assemblages (and related spatial patterns) must be quantitatively assessed to help identify high-risk locations. Previous assessments have largely focussed on the distributions of individual species; however, transmission dynamics are expected to depend on assemblage composition. Moreover, disease-diversity relationships have mainly been studied in the context of species loss, but assemblage composition and disease risk (e.g. infection prevalence in wildlife assemblages) can change without extinction. Based on the predicted distributions and abundances of 4466 mammal species, we estimated global patterns of disease risk through the calculation of the community-level basic reproductive ratio R0, an index of invasion potential, persistence, and maximum prevalence of a pathogen in a wildlife assemblage. For density-dependent diseases, we found that, in addition to tropical areas which are commonly viewed as infectious disease hotspots, northern temperate latitudes included high-risk areas. We also forecasted the effects of climate change and habitat loss from 2015 to 2035. Over this period, many local assemblages showed no net loss of species richness, but the assemblage composition (i.e. the mix of species and their abundances) changed considerably. Simultaneously, most areas experienced a decreased risk of density-dependent diseases but an increased risk of frequency-dependent diseases. We further explored the factors driving these changes in disease risk. Our results suggest that biodiversity and changes therein jointly influence disease risk. Understanding these changes and their drivers and ultimately identifying emerging infectious disease hotspots can help health officials prioritize resource distribution.
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Affiliation(s)
- Yingying X. G. Wang
- Wildlife Ecology and Conservation GroupWageningen University and ResearchWageningenThe Netherlands
- Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskyläFinland
| | - Kevin D. Matson
- Wildlife Ecology and Conservation GroupWageningen University and ResearchWageningenThe Netherlands
| | - Luca Santini
- Department of Biology and Biotechnologies “Charles Darwin”Sapienza University of RomeRomeItaly
- Institute of Research on Terrestrial Ecosystems (CNR‐IRET)National Research CouncilMonterotondo (Rome)Italy
- Department of Environmental ScienceRadboud UniversityNijmegenThe Netherlands
| | - Piero Visconti
- International Institute for Applied System AnalysisLaxenburgAustria
- Institute of ZoologyZoological Society of LondonLondonUK
| | - Jelle P. Hilbers
- Department of Environmental ScienceRadboud UniversityNijmegenThe Netherlands
| | | | - Yanjie Xu
- Wildlife Ecology and Conservation GroupWageningen University and ResearchWageningenThe Netherlands
- The Finnish Museum of Natural HistoryUniversity of HelsinkiHelsinkiFinland
| | - Herbert H. T. Prins
- Wildlife Ecology and Conservation GroupWageningen University and ResearchWageningenThe Netherlands
- Department of Animal SciencesWageningen University and ResearchWageningenThe Netherlands
| | | | - Zheng Y. X. Huang
- Wildlife Ecology and Conservation GroupWageningen University and ResearchWageningenThe Netherlands
- College of Life SciencesNanjing Normal UniversityNanjingChina
| | - Willem F. de Boer
- Wildlife Ecology and Conservation GroupWageningen University and ResearchWageningenThe Netherlands
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20
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Keesing F, Ostfeld RS. Dilution effects in disease ecology. Ecol Lett 2021; 24:2490-2505. [PMID: 34482609 PMCID: PMC9291114 DOI: 10.1111/ele.13875] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 08/19/2021] [Indexed: 01/03/2023]
Abstract
For decades, people have reduced the transmission of pathogens by adding low‐quality hosts to managed environments like agricultural fields. More recently, there has been interest in whether similar ‘dilution effects’ occur in natural disease systems, and whether these effects are eroded as diversity declines. For some pathogens of plants, humans and other animals, the highest‐quality hosts persist when diversity is lost, so that high‐quality hosts dominate low‐diversity communities, resulting in greater pathogen transmission. Meta‐analyses reveal that these natural dilution effects are common. However, studying them remains challenging due to limitations on the ability of researchers to manipulate many disease systems experimentally, difficulties of acquiring data on host quality and confusion about what should and should not be considered a dilution effect. Because dilution effects are widely used in managed disease systems and have been documented in a variety of natural disease systems, their existence should not be considered controversial. Important questions remain about how frequently they occur and under what conditions to expect them. There is also ongoing confusion about their relationships to both pathogen spillover and general biogeographical correlations between diversity and disease, which has resulted in an inconsistent and confusing literature. Progress will require rigorous and creative research.
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21
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Kain MP, Skinner EB, van den Hurk AF, McCallum H, Mordecai EA. Physiology and ecology combine to determine host and vector importance for Ross River virus. eLife 2021; 10:e67018. [PMID: 34414887 PMCID: PMC8457839 DOI: 10.7554/elife.67018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 08/19/2021] [Indexed: 01/19/2023] Open
Abstract
Identifying the key vector and host species that drive the transmission of zoonotic pathogens is notoriously difficult but critical for disease control. We present a nested approach for quantifying the importance of host and vectors that integrates species' physiological competence with their ecological traits. We apply this framework to a medically important arbovirus, Ross River virus (RRV), in Brisbane, Australia. We find that vertebrate hosts with high physiological competence are not the most important for community transmission; interactions between hosts and vectors largely underpin the importance of host species. For vectors, physiological competence is highly important. Our results identify primary and secondary vectors of RRV and suggest two potential transmission cycles in Brisbane: an enzootic cycle involving birds and an urban cycle involving humans. The framework accounts for uncertainty from each fitted statistical model in estimates of species' contributions to transmission and has has direct application to other zoonotic pathogens.
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Affiliation(s)
- Morgan P Kain
- Department of Biology, Stanford UniversityStanfordUnited States
- Natural Capital Project, Woods Institute for the Environment, Stanford UniversityStanfordUnited States
| | - Eloise B Skinner
- Department of Biology, Stanford UniversityStanfordUnited States
- Centre for Planetary Health and Food Security, Griffith UniversityGold CoastAustralia
| | - Andrew F van den Hurk
- Public Health Virology, Forensic and Scientific Services, Department of HealthBrisbaneAustralia
| | - Hamish McCallum
- Centre for Planetary Health and Food Security, Griffith UniversityGold CoastAustralia
| | - Erin A Mordecai
- Department of Biology, Stanford UniversityStanfordUnited States
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22
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Cornelius Ruhs E, Becker DJ, Oakey SJ, Ogunsina O, Fenton MB, Simmons NB, Martin LB, Downs CJ. Body size affects immune cell proportions in birds and non-volant mammals, but not bats. J Exp Biol 2021; 224:269058. [PMID: 34104965 DOI: 10.1242/jeb.241109] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 06/02/2021] [Indexed: 01/02/2023]
Abstract
Powered flight has evolved several times in vertebrates and constrains morphology and physiology in ways that likely have shaped how organisms cope with infections. Some of these constraints probably have impacts on aspects of immunology, such that larger fliers might prioritize risk reduction and safety. Addressing how the evolution of flight may have driven relationships between body size and immunity could be particularly informative for understanding the propensity of some taxa to harbor many virulent and sometimes zoonotic pathogens without showing clinical disease. Here, we used a comparative framework to quantify scaling relationships between body mass and the proportions of two types of white blood cells - lymphocytes and granulocytes (neutrophils/heterophils) - across 63 bat species, 400 bird species and 251 non-volant mammal species. By using phylogenetically informed statistical models on field-collected data from wild Neotropical bats and from captive bats, non-volant mammals and birds, we show that lymphocyte and neutrophil proportions do not vary systematically with body mass among bats. In contrast, larger birds and non-volant mammals have disproportionately higher granulocyte proportions than expected for their body size. Our inability to distinguish bat lymphocyte scaling from birds and bat granulocyte scaling from all other taxa suggests there may be other ecological explanations (i.e. not flight related) for the cell proportion scaling patterns. Future comparative studies of wild bats, birds and non-volant mammals of similar body mass should aim to further differentiate evolutionary effects and other aspects of life history on immune defense and its role in the tolerance of (zoonotic) infections.
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Affiliation(s)
- Emily Cornelius Ruhs
- Global Health and Infectious Disease Research, University of South Florida, Tampa, FL 33612, USA
| | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Samantha J Oakey
- Global Health and Infectious Disease Research, University of South Florida, Tampa, FL 33612, USA
| | - Ololade Ogunsina
- Global Health and Infectious Disease Research, University of South Florida, Tampa, FL 33612, USA
| | - M Brock Fenton
- Department of Biology, Western University, London, ON, Canada, N6A 5B7
| | - Nancy B Simmons
- Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York, NY 10024-5102, USA
| | - Lynn B Martin
- Global Health and Infectious Disease Research, University of South Florida, Tampa, FL 33612, USA
| | - Cynthia J Downs
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210, USA
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23
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Martin LB, Hanson HE, Hauber ME, Ghalambor CK. Genes, Environments, and Phenotypic Plasticity in Immunology. Trends Immunol 2021; 42:198-208. [PMID: 33518415 DOI: 10.1016/j.it.2021.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/31/2020] [Accepted: 01/05/2021] [Indexed: 12/30/2022]
Abstract
For most of its history, immunology has sought to control environmental variation to establish genetic causality. As with all biological traits though, variation among individuals arises by three broad pathways: genetic (G), environmental (E), and the interactive between the two (GxE); and immunity is no different. Here, we review the value of applying the evolutionary frameworks of phenotypic plasticity and reaction norms to immunology. Because standardized laboratory environments are vastly different from the conditions under which populations evolved, we hypothesize that immunology might presently be missing important phenotypic variation and even focusing on dysregulated molecular and cellular processes. Modest adjustments to study designs could make model organism immunology more productive, reproducible, and reflective of human physiology.
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Affiliation(s)
- Lynn B Martin
- Center for Global Health and Infectious Disease Research, University of South Florida, Tampa, FL, USA.
| | - Haley E Hanson
- Center for Global Health and Infectious Disease Research, University of South Florida, Tampa, FL, USA
| | - Mark E Hauber
- Department of Evolution, Ecology, and Behavior, School of Integrative Biology, University of Illinois, Urbana-Champaign, IL, USA
| | - Cameron K Ghalambor
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Biology, Colorado State University, Fort Collins, CO, USA
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24
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Valenzuela-Sánchez A, Wilber MQ, Canessa S, Bacigalupe LD, Muths E, Schmidt BR, Cunningham AA, Ozgul A, Johnson PTJ, Cayuela H. Why disease ecology needs life-history theory: a host perspective. Ecol Lett 2021; 24:876-890. [PMID: 33492776 DOI: 10.1111/ele.13681] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 12/16/2022]
Abstract
When facing an emerging infectious disease of conservation concern, we often have little information on the nature of the host-parasite interaction to inform management decisions. However, it is becoming increasingly clear that the life-history strategies of host species can be predictive of individual- and population-level responses to infectious disease, even without detailed knowledge on the specifics of the host-parasite interaction. Here, we argue that a deeper integration of life-history theory into disease ecology is timely and necessary to improve our capacity to understand, predict and mitigate the impact of endemic and emerging infectious diseases in wild populations. Using wild vertebrates as an example, we show that host life-history characteristics influence host responses to parasitism at different levels of organisation, from individuals to communities. We also highlight knowledge gaps and future directions for the study of life-history and host responses to parasitism. We conclude by illustrating how this theoretical insight can inform the monitoring and control of infectious diseases in wildlife.
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Affiliation(s)
- Andrés Valenzuela-Sánchez
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile.,ONG Ranita de Darwin, Valdivia and Santiago, Chile.,Centro de Investigación para la Sustentabilidad, Universidad Andrés Bello, Santiago, Chile
| | - Mark Q Wilber
- Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.,Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, University of Tennessee Institute of Agriculture, Knoxville, TN, 37996, USA
| | - Stefano Canessa
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Leonardo D Bacigalupe
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Erin Muths
- U.S. Geological Survey, 2150 Centre Avenue Bldg C, Fort Collins, Colorado, 80526, USA
| | - Benedikt R Schmidt
- Institut für Evolutionsbiologie und Umweltwissenschaften, Universität Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.,Info Fauna Karch, UniMail, Bâtiment G, Bellevaux 51, 2000, Neuchâtel, Switzerland
| | - Andrew A Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Arpat Ozgul
- Institut für Evolutionsbiologie und Umweltwissenschaften, Universität Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Pieter T J Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, 80309, USA
| | - Hugo Cayuela
- IBIS, Department of Biology, University Laval, Pavillon Charles-Eugène-Marchand, Avenue de la Médecine, Quebec City, Canada.,Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
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25
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Albery GF, Becker DJ. Fast-lived Hosts and Zoonotic Risk. Trends Parasitol 2020; 37:117-129. [PMID: 33214097 DOI: 10.1016/j.pt.2020.10.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/25/2020] [Accepted: 10/26/2020] [Indexed: 01/02/2023]
Abstract
Because most emerging human pathogens originate in mammals, many studies aim to identify host traits that determine the risk of sourcing zoonotic outbreaks. Studies regularly assert that 'fast-lived' mammal species exhibiting greater fecundity and shorter lifespans tend to host more zoonoses; however, the causes of this association remain poorly understood and they cover a range of immune and nonimmune mechanisms. We discuss these drivers in the context of evolutionary ecology and wildlife-human interactions. Ultimately, differentiating these mechanisms will require linking interspecific variation in life history with immunity, pathogen diversity, transmissibility, and zoonotic risk, and critical data gaps currently limit our ability to do so. We highlight sampling and analytical frameworks to address this gap and to better inform zoonotic reservoir prediction.
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Affiliation(s)
- Gregory F Albery
- Department of Biology, Georgetown University, Washington, DC, USA.
| | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, OK, USA.
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26
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Walsh MG, Hossain S. Population structure and diet generalism define a preliminary ecological profile of zoonotic virus hosts in the Western Ghats, India. Epidemics 2020; 33:100416. [PMID: 33161184 DOI: 10.1016/j.epidem.2020.100416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 09/09/2020] [Accepted: 10/30/2020] [Indexed: 12/18/2022] Open
Abstract
The rainforests of the Western Ghats exhibit some of the highest biodiversity on the planet, and yet are undergoing rapid land use change due to the expansion of agriculture and other industries. As the landscape of the region is transformed, more people are coming into conflict with wildlife and becoming exposed to pathogens that previously circulated beyond the boundaries of human incursion. Despite an ecological knowledge imperative, this emerging landscape is ill-defined with respect to the ecology of zoonotic viruses and their mammalian wildlife hosts. Without a better understanding of the underlying infection ecology, the epidemiology of viral spillover will remain elusive and unsuited to the task of predicting and preventing outbreaks. The current investigation explored the association between mammalian zoonotic virus richness and species-level landscape, life-history, and dietary traits to describe an initial ecological profile of zoonotic virus hosts in the Western Ghats. Social group composition and dietary forage were both non-linearly associated with greater zoonotic viral richness among these species, whereby species active in smaller social groups, albeit in higher population densities, and exhibiting a tendency toward a generalist diet hosted more zoonotic viruses. While these findings provide no definitive ecological demarcation of zoonotic virus hosts or their contribution to viral maintenance or amplification, it is expected that this preliminary profile can help to develop targeted wildlife pathogen surveillance programs and to expand the current approach to epidemiological modelling of emerging zoonoses in the region, which typically do not account for the macroecological parameters of infection transmission.
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Affiliation(s)
- Michael G Walsh
- The University of Sydney, Faculty of Medicine and Health, Marie Bashir Institute for Infectious Diseases and Biosecurity, Westmead, New South Wales, Australia; The University of Sydney, Faculty of Medicine and Health, Westmead Institute for Medical Research, Westmead, New South Wales, Australia; Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India.
| | - Shah Hossain
- The University of Sydney, Faculty of Medicine and Health, Marie Bashir Institute for Infectious Diseases and Biosecurity, Westmead, New South Wales, Australia; The University of Sydney, Faculty of Medicine and Health, Westmead Institute for Medical Research, Westmead, New South Wales, Australia; Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
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27
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Large-scale disease patterns explained by climatic seasonality and host traits. Oecologia 2020; 194:723-733. [DOI: 10.1007/s00442-020-04782-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 10/09/2020] [Indexed: 12/19/2022]
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Becker DJ, Seifert SN, Carlson CJ. Beyond Infection: Integrating Competence into Reservoir Host Prediction. Trends Ecol Evol 2020; 35:1062-1065. [PMID: 32921517 PMCID: PMC7483075 DOI: 10.1016/j.tree.2020.08.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/18/2020] [Accepted: 08/25/2020] [Indexed: 12/02/2022]
Abstract
Most efforts to predict novel reservoirs of zoonotic pathogens use information about host exposure and infection rather than competence, defined as the ability to transmit pathogens. Better obtaining and integrating competence data into statistical models as covariates, as the response variable, and through postmodel validation should improve predictive research.
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Affiliation(s)
- Daniel J Becker
- Department of Biology, Indiana University, Bloomington, IN, USA.
| | - Stephanie N Seifert
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Colin J Carlson
- Center for Global Health Science and Security, Georgetown University Medical Center, Washington, D.C., USA
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29
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Ruhs EC, Martin LB, Downs CJ. The impacts of body mass on immune cell concentrations in birds. Proc Biol Sci 2020; 287:20200655. [PMID: 32900319 DOI: 10.1098/rspb.2020.0655] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Body mass affects many biological traits, but its impacts on immune defences are fairly unknown. Recent research on mammals found that neutrophil concentrations disproportionately increased (scaled hypermetrically) with body mass, a result not predicted by any existing theory. Although the scaling relationship for mammals might predict how leucocyte concentrations scale with body mass in other vertebrates, vertebrate classes are distinct in many ways that might affect their current and historic interactions with parasites and hence the evolution of their immune systems. Subsequently, here, we asked which existing scaling hypothesis best-predicts relationships between body mass and lymphocyte, eosinophil and heterophil concentrations-the avian functional equivalent of neutrophils-among more than 100 species of birds. We then examined the predictive power of body mass relative to life-history variation, as extensive literature indicates that the timing of key life events has influenced immune system variation among species. Finally, we ask whether avian scaling patterns differ from the patterns we observed in mammals. We found that an intercept-only model best explained lymphocyte and eosinophil concentrations among birds, indicating that the concentrations of these cell types were both independent of body mass. For heterophils, however, body mass explained 31% of the variation in concentrations among species, much more than life-history variation (4%). As with mammalian neutrophils, avian heterophils scaled hypermetrically (b = 0.19 ± 0.05), but more steeply than mammals (approx. 1.5 ×; 0.11 ± 0.03). As such, we discuss why birds might require more broadly protective cells compared to mammals of the same body size. Overall, body mass appears to have strong influences on the architecture of immune systems.
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Affiliation(s)
| | - Lynn B Martin
- Global and Planetary Health, University of South Florida, Tampa, FL 33620, USA
| | - Cynthia J Downs
- Environmental & Forest Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210, USA
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Cator LJ, Johnson LR, Mordecai EA, Moustaid FE, Smallwood TRC, LaDeau SL, Johansson MA, Hudson PJ, Boots M, Thomas MB, Power AG, Pawar S. The Role of Vector Trait Variation in Vector-Borne Disease Dynamics. Front Ecol Evol 2020; 8:189. [PMID: 32775339 PMCID: PMC7409824 DOI: 10.3389/fevo.2020.00189] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Many important endemic and emerging diseases are transmitted by vectors that are biting arthropods. The functional traits of vectors can affect pathogen transmission rates directly and also through their effect on vector population dynamics. Increasing empirical evidence shows that vector traits vary significantly across individuals, populations, and environmental conditions, and at time scales relevant to disease transmission dynamics. Here, we review empirical evidence for variation in vector traits and how this trait variation is currently incorporated into mathematical models of vector-borne disease transmission. We argue that mechanistically incorporating trait variation into these models, by explicitly capturing its effects on vector fitness and abundance, can improve the reliability of their predictions in a changing world. We provide a conceptual framework for incorporating trait variation into vector-borne disease transmission models, and highlight key empirical and theoretical challenges. This framework provides a means to conceptualize how traits can be incorporated in vector borne disease systems, and identifies key areas in which trait variation can be explored. Determining when and to what extent it is important to incorporate trait variation into vector borne disease models remains an important, outstanding question.
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Affiliation(s)
- Lauren J. Cator
- Department of Life Sciences, Imperial College London, Ascot, United Kingdom
| | - Leah R. Johnson
- Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Erin A. Mordecai
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Fadoua El Moustaid
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- BresMed America Inc, Las Vegas, NV, United States
| | | | - Shannon L. LaDeau
- The Cary Institute of Ecosystem Studies, Millbrook, NY, United States
| | | | - Peter J. Hudson
- Center for Infectious Disease Dynamics and Department of Biology, Pennsylvania State University, University Park, PA, United States
| | - Michael Boots
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Matthew B. Thomas
- Department of Entomology, Pennsylvania State University, University Park, PA, United States
| | - Alison G. Power
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
| | - Samraat Pawar
- Department of Life Sciences, Imperial College London, Ascot, United Kingdom
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31
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Towards a mechanistic understanding of competence: a missing link in diversity-disease research. Parasitology 2020; 147:1159-1170. [PMID: 32517830 DOI: 10.1017/s0031182020000943] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Biodiversity loss may increase the risk of infectious disease in a phenomenon known as the dilution effect. Circumstances that increase the likelihood of disease dilution are: (i) when hosts vary in their competence, and (ii) when communities disassemble predictably, such that the least competent hosts are the most likely to go extinct. Despite the central role of competence in diversity-disease theory, we lack a clear understanding of the factors underlying competence, as well as the drivers and extent of its variation. Our perspective piece encourages a mechanistic understanding of competence and a deeper consideration of its role in diversity-disease relationships. We outline current evidence, emerging questions and future directions regarding the basis of competence, its definition and measurement, the roots of its variation and its role in the community ecology of infectious disease.
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Becker DJ, Speer KA, Brown AM, Fenton MB, Washburne AD, Altizer S, Streicker DG, Plowright RK, Chizhikov VE, Simmons NB, Volokhov DV. Ecological and evolutionary drivers of haemoplasma infection and bacterial genotype sharing in a Neotropical bat community. Mol Ecol 2020; 29:1534-1549. [PMID: 32243630 PMCID: PMC8299350 DOI: 10.1111/mec.15422] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 03/16/2020] [Accepted: 03/23/2020] [Indexed: 12/21/2022]
Abstract
Most emerging pathogens can infect multiple species, underlining the importance of understanding the ecological and evolutionary factors that allow some hosts to harbour greater infection prevalence and share pathogens with other species. However, our understanding of pathogen jumps is based primarily around viruses, despite bacteria accounting for the greatest proportion of zoonoses. Because bacterial pathogens in bats (order Chiroptera) can have conservation and human health consequences, studies that examine the ecological and evolutionary drivers of bacterial prevalence and barriers to pathogen sharing are crucially needed. Here were studied haemotropic Mycoplasma spp. (i.e., haemoplasmas) across a species-rich bat community in Belize over two years. Across 469 bats spanning 33 species, half of individuals and two-thirds of species were haemoplasma positive. Infection prevalence was higher for males and for species with larger body mass and colony sizes. Haemoplasmas displayed high genetic diversity (21 novel genotypes) and strong host specificity. Evolutionary patterns supported codivergence of bats and bacterial genotypes alongside phylogenetically constrained host shifts. Bat species centrality to the network of shared haemoplasma genotypes was phylogenetically clustered and unrelated to prevalence, further suggesting rare-but detectable-bacterial sharing between species. Our study highlights the importance of using fine phylogenetic scales when assessing host specificity and suggests phylogenetic similarity may play a key role in host shifts not only for viruses but also for bacteria. Such work more broadly contributes to increasing efforts to understand cross-species transmission and the epidemiological consequences of bacterial pathogens.
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Affiliation(s)
- Daniel J. Becker
- Department of BiologyIndiana UniversityBloomingtonINUSA
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
| | - Kelly A. Speer
- Richard Gilder Graduate SchoolAmerican Museum of Natural HistoryNew YorkNYUSA
- Department of Invertebrate ZoologyNational Museum of Natural HistorySmithsonian InstitutionWashingtonDCUSA
- Center for Conservation GenomicsSmithsonian Conservation Biology InstituteNational Zoological ParkWashingtonDCUSA
| | - Alexis M. Brown
- Department of Ecology and EvolutionStony Brook UniversityStony BrookNYUSA
| | | | - Alex D. Washburne
- Department of Microbiology and ImmunologyMontana State UniversityBozemanMTUSA
| | - Sonia Altizer
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
| | - Daniel G. Streicker
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- MRC–University of Glasgow Centre for Virus ResearchGlasgowUK
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Raina K. Plowright
- Department of Microbiology and ImmunologyMontana State UniversityBozemanMTUSA
| | - Vladimir E. Chizhikov
- Center for Biologics Evaluation and Research, Food and Drug AdministrationSilver SpringMDUSA
| | - Nancy B. Simmons
- Richard Gilder Graduate SchoolAmerican Museum of Natural HistoryNew YorkNYUSA
- Department of MammalogyDivision of Vertebrate ZoologyAmerican Museum of Natural HistoryNew YorkNYUSA
| | - Dmitriy V. Volokhov
- Center for Biologics Evaluation and Research, Food and Drug AdministrationSilver SpringMDUSA
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Walsh MG, Mor SM, Maity H, Hossain S. A preliminary ecological profile of Kyasanur Forest disease virus hosts among the mammalian wildlife of the Western Ghats, India. Ticks Tick Borne Dis 2020; 11:101419. [PMID: 32241712 DOI: 10.1016/j.ttbdis.2020.101419] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 02/27/2020] [Accepted: 03/20/2020] [Indexed: 01/31/2023]
Abstract
Kyasanur Forest disease (KFD) virus is one of India's severe arboviruses capable of causing prolonged debilitating disease. It has been expanding beyond its historical endemic locus at an alarming rate over the last two decades. The natural nidus of this zoonosis is located in the monsoon rainforest of the Western Ghats, India, which is one of the world's most important biodiversity hotspots. Definitive reservoir hosts for KFD virus (KFDV) have yet to be delineated, and thus much of the infection ecology of this virus, and its consequent transmission dynamics, remains uncertain. Given its unique biogeographical context, identifying ecological parameters of KFDV relevant to the virus' epidemiology has been complex and challenging. The challenge has been exacerbated by diminished research efforts in wildlife surveillance over the last two decades, coinciding with the expansion of the range of KFD across the region. The current investigation sought to define a preliminary ecological profile of KFDV hosts based on their life history and feeding traits to aid in re-establishing targeted wildlife surveillance and to discern those ecological traits of wildlife hosts that may improve our understanding of KFD epidemiology. The importance of fast-living among KFDV hosts was of special interest with respect to the latter aim. We compared mammalian traits between host and non-host species using general additive models and phylogenetic generalised linear models. This study found that both body mass and forest forage were strongly associated with mammalian host infection status, but that reproductive life history traits were not. These findings will help in structuring ecologically based wildlife surveillance and field investigations, while also helping to parameterise novel epidemiological models of zoonotic infection risk that incorporate species functional traits in a region where biogeography, landscape ecology, and community ecology manifest extraordinary complexity, particularly under growing anthropogenic pressure.
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Affiliation(s)
- Michael G Walsh
- The University of Sydney, Faculty of Medicine and Health, Marie Bashir Institute for Infectious Diseases and Biosecurity, Westmead, NSW, Australia; The University of Sydney, Faculty of Medicine and Health, Westmead Institute for Medical Research, Westmead, NSW, Australia; Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India.
| | - Siobhan M Mor
- University of Liverpool, Faculty of Health and Life Sciences, Institute of Infection and Global Health Liverpool, Merseyside, United Kingdom; The University of Sydney, Faculty of Science, School of Veterinary Science, Camperdown, NSW, Australia
| | - Hindol Maity
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Shah Hossain
- The University of Sydney, Faculty of Medicine and Health, Marie Bashir Institute for Infectious Diseases and Biosecurity, Westmead, NSW, Australia; Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
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34
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Becker DJ, Downs CJ, Martin LB. Multi-Scale Drivers of Immunological Variation and Consequences for Infectious Disease Dynamics. Integr Comp Biol 2020; 59:1129-1137. [PMID: 31559436 DOI: 10.1093/icb/icz138] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The immune system is the primary barrier to parasite infection, replication, and transmission following exposure, and variation in immunity can accordingly manifest in heterogeneity in traits that govern population-level infectious disease dynamics. While much work in ecoimmunology has focused on individual-level determinants of host immune defense (e.g., reproductive status and body condition), an ongoing challenge remains to understand the broader evolutionary and ecological contexts of this variation (e.g., phylogenetic relatedness and landscape heterogeneity) and to connect these differences into epidemiological frameworks. Ultimately, such efforts could illuminate general principles about the drivers of host defense and improve predictions and control of infectious disease. Here, we highlight recent work that synthesizes the complex drivers of immunological variation across biological scales of organization and scales these within-host differences to population-level infection outcomes. Such studies note the limitations involved in making species-level comparisons of immune phenotypes, stress the importance of spatial scale for immunology research, showcase several statistical tools for translating within-host data into epidemiological parameters, and provide theoretical frameworks for linking within- and between-host scales of infection processes. Building from these studies, we highlight several promising avenues for continued work, including the application of machine learning tools and phylogenetically controlled meta-analyses to immunology data and quantifying the joint spatial and temporal dependencies in immune defense using range expansions as model systems. We also emphasize the use of organismal traits (e.g., host tolerance, competence, and resistance) as a way to interlink various scales of analysis. Such continued collaboration and disciplinary cross-talk among ecoimmunology, disease ecology, and mathematical modeling will facilitate an improved understanding of the multi-scale drivers and consequences of variation in host defense.
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Affiliation(s)
- Daniel J Becker
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA 30602, USA
| | - Cynthia J Downs
- Department of Biology, Hamilton College, Clinton, NY 13323, USA
| | - Lynn B Martin
- Department of Global and Planetary Health, University of South Florida, Tampa, FL 33620, USA
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35
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Becker DJ, Albery GF, Kessler MK, Lunn TJ, Falvo CA, Czirják GÁ, Martin LB, Plowright RK. Macroimmunology: The drivers and consequences of spatial patterns in wildlife immune defence. J Anim Ecol 2020; 89:972-995. [PMID: 31856309 DOI: 10.1111/1365-2656.13166] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 11/06/2019] [Indexed: 01/26/2023]
Abstract
The prevalence and intensity of parasites in wild hosts varies across space and is a key determinant of infection risk in humans, domestic animals and threatened wildlife. Because the immune system serves as the primary barrier to infection, replication and transmission following exposure, we here consider the environmental drivers of immunity. Spatial variation in parasite pressure, abiotic and biotic conditions, and anthropogenic factors can all shape immunity across spatial scales. Identifying the most important spatial drivers of immunity could help pre-empt infectious disease risks, especially in the context of how large-scale factors such as urbanization affect defence by changing environmental conditions. We provide a synthesis of how to apply macroecological approaches to the study of ecoimmunology (i.e. macroimmunology). We first review spatial factors that could generate spatial variation in defence, highlighting the need for large-scale studies that can differentiate competing environmental predictors of immunity and detailing contexts where this approach might be favoured over small-scale experimental studies. We next conduct a systematic review of the literature to assess the frequency of spatial studies and to classify them according to taxa, immune measures, spatial replication and extent, and statistical methods. We review 210 ecoimmunology studies sampling multiple host populations. We show that whereas spatial approaches are relatively common, spatial replication is generally low and unlikely to provide sufficient environmental variation or power to differentiate competing spatial hypotheses. We also highlight statistical biases in macroimmunology, in that few studies characterize and account for spatial dependence statistically, potentially affecting inferences for the relationships between environmental conditions and immune defence. We use these findings to describe tools from geostatistics and spatial modelling that can improve inference about the associations between environmental and immunological variation. In particular, we emphasize exploratory tools that can guide spatial sampling and highlight the need for greater use of mixed-effects models that account for spatial variability while also allowing researchers to account for both individual- and habitat-level covariates. We finally discuss future research priorities for macroimmunology, including focusing on latitudinal gradients, range expansions and urbanization as being especially amenable to large-scale spatial approaches. Methodologically, we highlight critical opportunities posed by assessing spatial variation in host tolerance, using metagenomics to quantify spatial variation in parasite pressure, coupling large-scale field studies with small-scale field experiments and longitudinal approaches, and applying statistical tools from macroecology and meta-analysis to identify generalizable spatial patterns. Such work will facilitate scaling ecoimmunology from individual- to habitat-level insights about the drivers of immune defence and help predict where environmental change may most alter infectious disease risk.
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Affiliation(s)
- Daniel J Becker
- Department of Biology, Indiana University, Bloomington, IN, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Gregory F Albery
- Department of Biology, Georgetown University, Washington, DC, USA
| | | | - Tamika J Lunn
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland, Australia
| | - Caylee A Falvo
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Lynn B Martin
- Department of Global and Planetary Health, University of South Florida, Tampa, FL, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
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36
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Downs CJ, Dochtermann NA, Ball R, Klasing KC, Martin LB. The Effects of Body Mass on Immune Cell Concentrations of Mammals. Am Nat 2020; 195:107-114. [DOI: 10.1086/706235] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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37
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Cooke SJ, Madliger CL, Cramp RL, Beardall J, Burness G, Chown SL, Clark TD, Dantzer B, de la Barrera E, Fangue NA, Franklin CE, Fuller A, Hawkes LA, Hultine KR, Hunt KE, Love OP, MacMillan HA, Mandelman JW, Mark FC, Martin LB, Newman AEM, Nicotra AB, Robinson SA, Ropert-Coudert Y, Rummer JL, Seebacher F, Todgham AE. Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: reflections and a horizon scan. CONSERVATION PHYSIOLOGY 2020; 8:coaa016. [PMID: 32274063 PMCID: PMC7125050 DOI: 10.1093/conphys/coaa016] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 01/27/2020] [Accepted: 02/10/2020] [Indexed: 05/21/2023]
Abstract
Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of 'success stories' is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider how conservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a 'horizon scan', we further explore ways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmental management and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users.
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Affiliation(s)
- Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada
- Corresponding author: Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada.
| | - Christine L Madliger
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada
| | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Gary Burness
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Steven L Chown
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Timothy D Clark
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 14 3216, Australia
| | - Ben Dantzer
- Department of Psychology, Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Erick de la Barrera
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701, Morelia, Michoacán, 58190, Mexico
| | - Nann A Fangue
- Department of Wildlife, Fish & Conservation Biology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, 7 York Rd, Parktown, 2193, South Africa
| | - Lucy A Hawkes
- College of Life and Environmental Sciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ 85008, USA
| | - Kathleen E Hunt
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| | - Oliver P Love
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada
| | - Heath A MacMillan
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Dr., Ottawa, ON K1S 5B6, Canada
| | - John W Mandelman
- Anderson Cabot Center for Ocean Life, New England Aquarium, 1 Central Wharf, Boston, MA 02110, USA
| | - Felix C Mark
- Department of Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27574 Bremerhaven, Germany
| | - Lynn B Martin
- Global Health and Infectious Disease Research, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL 33612, USA
| | - Amy E M Newman
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Adrienne B Nicotra
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Sharon A Robinson
- School of Earth, Atmospheric and Life Sciences (SEALS) and Centre for Sustainable Ecosystem Solutions, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Yan Ropert-Coudert
- Centre d'Etudes Biologiques de Chizé, CNRS UMR 7372 - La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Jodie L Rummer
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 5811, Australia
| | - Frank Seebacher
- School of Life and Environmental Sciences A08, University of Sydney, NSW 2006, Australia
| | - Anne E Todgham
- Department of Animal Science, University of California Davis, One Shields Ave. Davis, CA, 95616, USA
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Martin LB, Kernbach ME, Unnasch TR. Distinct effects of acute versus chronic corticosterone exposure on Zebra finch responses to West Nile virus. CONSERVATION PHYSIOLOGY 2019; 7:coz094. [PMID: 31824675 PMCID: PMC6894510 DOI: 10.1093/conphys/coz094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/28/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
Wild animals are exposed to both short- (acute) and long-term (chronic) stressors. The glucocorticoid hormones, such as corticosterone (CORT), facilitate coping with such stressors, but these hormones can have quite distinct effects contingent on the duration of their elevation. Previously, we found that experimental elevation of CORT for 2 days (via implantation) affected zebra finch (Taeniopygia guttata) responses to West Nile virus (WNV). CORT-elevated birds had higher viremia for at least 2 days longer than controls, and West Nile virus (WNV)-associated mortality occurred only in CORT-elevated birds. Here, we queried how acute elevations of CORT, via injection an hour prior to WNV exposure, would affect host responses, as short-term CORT elevations can be protective in other species. Although CORT injections and implantations elevated circulating CORT to a similar degree, the type of CORT exposure had quite distinct effects on WNV responses. CORT-implanted individuals reached higher viremia and suffered more mortality to WNV than control and CORT-injected individuals. However, CORT-implanted birds maintained body mass better during infection than the other two groups. Our results further support the possibility that chronic physiological stress affects aspects of host competence and potentially community-level WNV disease dynamics.
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Affiliation(s)
- Lynn B Martin
- Global Health and Infectious Disease Research Center, University of South Florida, Tampa, FL 33620, USA
| | - Meredith E Kernbach
- Global Health and Infectious Disease Research Center, University of South Florida, Tampa, FL 33620, USA
| | - Thomas R Unnasch
- Global Health and Infectious Disease Research Center, University of South Florida, Tampa, FL 33620, USA
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39
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Grab KM, Hiller BJ, Hurlbert JH, Ingram ME, Parker AB, Pokutnaya DY, Knutie SA. Host tolerance and resistance to parasitic nest flies differs between two wild bird species. Ecol Evol 2019; 9:12144-12155. [PMID: 31832149 PMCID: PMC6854101 DOI: 10.1002/ece3.5682] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 08/31/2019] [Accepted: 09/06/2019] [Indexed: 12/25/2022] Open
Abstract
Hosts have developed and evolved defense strategies to limit parasite damage. Hosts can reduce the damage that parasites cause by decreasing parasite fitness (resistance) or without affecting parasite fitness (tolerance). Because a parasite species can infect multiple host species, determining the effect of the parasite on these hosts and identifying host defense strategies can have important implications for multi-host-parasite dynamics.Over 2 years, we experimentally manipulated parasitic flies (Protocalliphora sialia) in the nests of tree swallows (Tachycineta bicolor) and eastern bluebirds (Sialia sialis). We then determined the effects of the parasites on the survival of nestlings and compared defense strategies between host species. We compared resistance between host species by quantifying parasite densities (number of parasites per gram of host) and measured nestling antibody levels as a mechanism of resistance. We quantified tolerance by determining the relationship between parasite density and nestling survival and blood loss by measuring hemoglobin levels (as a proxy of blood recovery) and nestling provisioning rates (as a proxy of parental compensation for resources lost to the parasite) as potential mechanisms of tolerance.For bluebirds, parasite density was twice as high as for swallows. Both host species were tolerant to the effects of P. sialia on nestling survival at their respective parasite loads but neither species were tolerant to the blood loss to the parasite. However, swallows were more resistant to P. sialia compared to bluebirds, which was likely related to the higher antibody-mediated immune response in swallow nestlings. Neither blood recovery nor parental compensation were mechanisms of tolerance.Overall, these results suggest that bluebirds and swallows are both tolerant of their respective parasite loads but swallows are more resistant to the parasites. These results demonstrate that different host species have evolved similar and different defenses against the same species of parasite.
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Affiliation(s)
- Kirstine M. Grab
- Department of Ecology, Evolution, and BehaviorUniversity of Minnesota Twin CitiesSt. PaulMNUSA
| | | | | | | | - Alexandra B. Parker
- Department of Ecology, Evolution, and BehaviorUniversity of Minnesota Twin CitiesSt. PaulMNUSA
| | | | - Sarah A. Knutie
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsCTUSA
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Stewart Merrill TE, Hall SR, Merrill L, Cáceres CE. Variation in Immune Defense Shapes Disease Outcomes in Laboratory and Wild Daphnia. Integr Comp Biol 2019; 59:1203-1219. [DOI: 10.1093/icb/icz079] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Host susceptibility may be critical for the spread of infectious disease, and understanding its basis is a goal of ecological immunology. Here, we employed a series of mechanistic tests to evaluate four factors commonly assumed to influence host susceptibility: parasite exposure, barriers to infection, immune responses, and body size. We tested these factors in an aquatic host–parasite system (Daphnia dentifera and the fungal parasite, Metschnikowia bicuspidata) using both laboratory-reared and field-collected hosts. We found support for each factor as a driver of infection. Elevated parasite exposure, which occurs through consumption of infectious fungal spores, increased a host’s probability of infection. The host’s gut epithelium functioned as a barrier to infection, but in the opposite manner from which we predicted: thinner anterior gut epithelia were more resistant to infectious spores than thick epithelia. This relationship may be mediated by structural attributes associated with epithelial cell height. Fungal spores that breached the host’s gut barrier elicited an intensity-dependent hemocyte response that decreased the probability of infection for some Daphnia. Although larger body sizes were associated with increased levels of spore ingestion, larger hosts also had lower frequencies of parasite attack, less penetrable gut barriers, and stronger hemocyte responses. After investigating which mechanisms underlie host susceptibility, we asked: do these four factors contribute equally or asymmetrically to the outcome of infection? An information-theoretic approach revealed that host immune defenses (barriers and immune responses) played the strongest roles in mediating infection outcomes. These two immunological traits may be valuable metrics for linking host susceptibility to the spread of infectious disease.
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Affiliation(s)
- Tara E Stewart Merrill
- Program in Ecology, Evolution, and Conservation Biology, University of Illinois, Urbana, IL 61801, USA
| | - Spencer R Hall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Loren Merrill
- Department of Natural Resources, University of Illinois, Urbana, IL 61801, USA
| | - Carla E Cáceres
- Program in Ecology, Evolution, and Conservation Biology, University of Illinois, Urbana, IL 61801, USA
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