1
|
Zeng Y, Xiao X, Yang F, Li T, Huang Y, Shi X, Lai C. Progress towards understanding the effects of artificial light on the transmission of vector-borne diseases. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 283:116780. [PMID: 39126816 DOI: 10.1016/j.ecoenv.2024.116780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 07/04/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024]
Abstract
Artificial light at night (ALAN) is a common form of light pollution worldwide, and the intensity, timing, duration, and wavelength of light exposure can affect biological rhythms, which can lead to metabolic, reproductive, and immune dysfunctions and consequently, host-pathogen interactions. Insect vector-borne diseases are a global problem that needs to be addressed, and ALAN plays an important role in disease transmission by affecting the habits and physiological functions of vector organisms. In this work, we describe the mechanisms by which ALAN affects host physiology and biochemistry, host-parasite interactions, and vector-borne viruses and propose preventive measures for related infectious diseases to minimize the effects of artificial light on vector-borne diseases.
Collapse
Affiliation(s)
- Ying Zeng
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, and School of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Xiaoping Xiao
- Ganzhou Key Laboratory for Drug Screening and Discovery, School of Geography and Environmental Engineering, Gannan Normal University, Ganzhou, Jiangxi 341000, China
| | - Fan Yang
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China; School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Tong Li
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Yalan Huang
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Xiaolu Shi
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Chongde Lai
- Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, and School of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; Jiangxi Key Laboratory for Excavation and Utilization of Agricultural Microorganisms, Jiangxi Agricultural University, Nanchang 330045, China
| |
Collapse
|
2
|
Suh DC, Lance SL, Park AW. Abiotic and biotic factors jointly influence the contact and environmental transmission of a generalist pathogen. Ecol Evol 2024; 14:e70167. [PMID: 39157664 PMCID: PMC11329300 DOI: 10.1002/ece3.70167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 07/26/2024] [Accepted: 07/30/2024] [Indexed: 08/20/2024] Open
Abstract
The joint influence of abiotic and biotic factors is important for understanding the transmission of generalist pathogens. Abiotic factors such as temperature can directly influence pathogen persistence in the environment and will also affect biotic factors, such as host community composition and abundance. At intermediate spatial scales, the effects of temperature, community composition, and host abundance are expected to contribute to generalist pathogen transmission. We use a simple transmission model to explain and predict how host community composition, host abundance, and environmental pathogen persistence times can independently and jointly influence transmission. Our transmission model clarifies how abiotic and biotic factors can synergistically support the transmission of a pathogen. The empirical data show that high community competence, high abundance, and low temperatures correlate with high levels of transmission of ranavirus in larval amphibian communities. Discrete wetlands inhabited by larval amphibians in the presence of ranavirus provide a compelling case study comprising distinct host communities at a spatial scale anticipated to demonstrate abiotic and biotic influence on transmission. We use these host communities to observe phenomena demonstrated in our theoretical model. These findings emphasize the importance of considering both abiotic and biotic factors, and concomitant direct and indirect mechanisms, in the study of pathogen transmission and should extend to other generalist pathogens with the capacity for environmental transmission.
Collapse
Affiliation(s)
- Daniel C. Suh
- Odum School of EcologyUniversity of GeorgiaAthensGeorgiaUSA
- Center for the Ecology of Infectious DiseasesUniversity of GeorgiaAthensGeorgiaUSA
| | - Stacey L. Lance
- Center for the Ecology of Infectious DiseasesUniversity of GeorgiaAthensGeorgiaUSA
- Savannah River Ecology LaboratoryUniversity of GeorgiaAikenSouth CarolinaUSA
| | - Andrew W. Park
- Odum School of EcologyUniversity of GeorgiaAthensGeorgiaUSA
- Center for the Ecology of Infectious DiseasesUniversity of GeorgiaAthensGeorgiaUSA
- Department of Infectious Diseases, College of Veterinary MedicineUniversity of GeorgiaAthensGeorgiaUSA
| |
Collapse
|
3
|
Buss N, Hua J. Host exposure to a common pollutant can influence diversity-disease relationships. J Anim Ecol 2023; 92:2151-2162. [PMID: 37587564 DOI: 10.1111/1365-2656.13988] [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: 10/03/2022] [Accepted: 05/15/2023] [Indexed: 08/18/2023]
Abstract
Hosts and parasites are embedded in communities where species richness and composition can influence disease outcomes (diversity-disease relationships). The direction and magnitude of diversity-disease relationships are influenced by variation in competence (ability to support and transmit infections) of hosts in a community. However, host susceptibility to parasites, which mediates host competence, is not static and is influenced by environmental factors, including pollutants. Despite the role that pollutants can play in augmenting host susceptibility, how pollutants influence diversity-disease dynamics is not well understood. Using an amphibian-trematode model, we tested how NaCl influences diversity-disease dynamics. We predicted that NaCl exposure can alter relative susceptibility of host species to trematodes, leading to cascading effects on the diversity-disease relationship. To test these predictions, we exposed hosts to benign or NaCl environments and generated communities that differed in number and composition of host species. We exposed these communities to trematodes and measured disease outcomes at the community (total infections across all hosts within a community) and species levels (average number of infections per host species within a community). Host species differed in their relative susceptibility to trematodes when exposed to NaCl. Consequently, at the community level (total infections across all hosts within a community), we only detected diversity-disease relationships (dilution effects) in communities where hosts were exposed to NaCl. At the species level, disease outcomes (average number of infections/species) and whether multi-species communities supported lower number of infections relative to single-species communities depended on community composition. Notably, however, as with overall community infection, diversity-disease relationships only emerged when hosts were exposed to NaCl. Synthesis. Pollutants are ubiquitous in nature and can influence disease dynamics across a number of host-parasite systems. Here, we show that NaCl exposure can alter the relative susceptibility of host species to parasites, influencing the relationship between biodiversity and disease at both community and species levels. Collectively, our study contributes to the limited knowledge surrounding environmental mediators of host susceptibility and their influence on diversity-disease dynamics.
Collapse
Affiliation(s)
- Nicholas Buss
- Department of Biological Sciences, Binghamton University (SUNY), Binghamton, New York, USA
| | - Jessica Hua
- Department of Biological Sciences, Binghamton University (SUNY), Binghamton, New York, USA
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| |
Collapse
|
4
|
Koller KK, Kernbach ME, Reese D, Unnasch TR, Martin LB. House Sparrows Vary Seasonally in Their Ability to Transmit West Nile Virus. Physiol Biochem Zool 2023; 96:332-341. [PMID: 37713719 DOI: 10.1086/725888] [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: 09/17/2023]
Abstract
AbstractSeasonality in infectious disease prevalence is predominantly attributed to changes in exogenous risk factors. For vectored pathogens, high abundance, activity, and/or diversity of vectors can exacerbate disease risk for hosts. Conversely, many host defenses, particularly immune responses, are seasonally variable. Seasonality in host defenses has been attributed, in part, to the proximate (i.e., metabolic) and ultimate (i.e., reproductive fitness) costs of defense. In this study, our goal was to discern whether any seasonality is observable in how a common avian host, the house sparrow (Passer domesticus), copes with a common zoonotic arbovirus, the West Nile virus (WNV), when hosts are studied under controlled conditions. We hypothesized that if host biorhythms play a role in vector-borne disease seasonality, birds would be most vulnerable to WNV when breeding and/or molting (i.e., when other costly physiological activities are underway) and thus most transmissive of WNV at these times of year (unless birds died from infection). Overall, the results only partly supported our hypothesis. Birds were most transmissive of WNV in fall (after their molt is complete and when WNV is most prevalent in the environment), but WNV resistance, WNV tolerance, and WNV-dependent mortality did not vary among seasons. These results collectively imply that natural arboviral cycles could be partially underpinned by endogenous physiological changes in hosts. However, other disease systems warrant study, as this result could be specific to the nonnative and highly commensal nature of the house sparrow or a consequence of the relative recency of the arrival of WNV to the United States.
Collapse
|
5
|
Assis VR, Robert J, Titon SCM. Introduction to the special issue Amphibian immunity: stress, disease and ecoimmunology. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220117. [PMID: 37305915 PMCID: PMC10258669 DOI: 10.1098/rstb.2022.0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Amphibian populations have been declining worldwide, with global climate changes and infectious diseases being among the primary causes of this scenario. Infectious diseases are among the primary drivers of amphibian declines, including ranavirosis and chytridiomycosis, which have gained more attention lately. While some amphibian populations are led to extinction, others are disease-resistant. Although the host's immune system plays a major role in disease resistance, little is known about the immune mechanisms underlying amphibian disease resistance and host-pathogen interactions. As ectotherms, amphibians are directly subjected to changes in temperature and rainfall, which modulate stress-related physiology, including immunity and pathogen physiology associated with diseases. In this sense, the contexts of stress, disease and ecoimmunology are essential for a better understanding of amphibian immunity. This issue brings details about the ontogeny of the amphibian immune system, including crucial aspects of innate and adaptive immunity and how ontogeny can influence amphibian disease resistance. In addition, the papers in the issue demonstrate an integrated view of the amphibian immune system associated with the influence of stress on immune-endocrine interactions. The collective body of research presented herein can provide valuable insights into the mechanisms underlying disease outcomes in natural populations, particularly in the context of changing environmental conditions. These findings may ultimately enhance our ability to forecast effective conservation strategies for amphibian populations. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
Collapse
Affiliation(s)
- Vania Regina Assis
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, 05508-900 São Paulo, Brazil
- College of Public Health, University of South Florida, Tampa, FL 33612-9415, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA
| | | |
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Halliday FW, Czyżewski S, Laine AL. Intraspecific trait variation and changing life-history strategies explain host community disease risk along a temperature gradient. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220019. [PMID: 36744568 PMCID: PMC9900715 DOI: 10.1098/rstb.2022.0019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Predicting how climate change will affect disease risk is complicated by the fact that changing environmental conditions can affect disease through direct and indirect effects. Species with fast-paced life-history strategies often amplify disease, and changing climate can modify life-history composition of communities thereby altering disease risk. However, individuals within a species can also respond to changing conditions with intraspecific trait variation. To test the effect of temperature, as well as inter- and intraspecifc trait variation on community disease risk, we measured foliar disease and specific leaf area (SLA; a proxy for life-history strategy) on more than 2500 host (plant) individuals in 199 communities across a 1101 m elevational gradient in southeastern Switzerland. There was no direct effect of increasing temperature on disease. Instead, increasing temperature favoured species with higher SLA, fast-paced life-history strategies. This effect was balanced by intraspecific variation in SLA: on average, host individuals expressed lower SLA with increasing temperature, and this effect was stronger among species adapted to warmer temperatures and lower latitudes. These results demonstrate how impacts of changing temperature on disease may depend on how temperature combines and interacts with host community structure while indicating that evolutionary constraints can determine how these effects are manifested under global change. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.
Collapse
Affiliation(s)
- Fletcher W. Halliday
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
| | - Szymon Czyżewski
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
| | - Anna-Liisa Laine
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland,Research Centre for Ecological Change, Organismal & Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 65, Helsinki FI-00014, Finland
| |
Collapse
|
8
|
Bergen N, Krämer P, Romberg J, Wichels A, Gerlach G, Brinkhoff T. Shell Disease Syndrome Is Associated with Reduced and Shifted Epibacterial Diversity on the Carapace of the Crustacean Cancer pagurus. Microbiol Spectr 2022; 10:e0341922. [PMID: 36342282 PMCID: PMC9769784 DOI: 10.1128/spectrum.03419-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 09/09/2022] [Indexed: 11/09/2022] Open
Abstract
Cancer pagurus is highly susceptible to shell disease syndrome. However, little is known about concomitant changes in the epibacterial community. We compared the bacterial communities of black spot affected and nonaffected areas of the carapace by amplicon sequencing of 16S rRNA genes and 16S rRNA. Within each spot, bacterial communities of affected areas were less diverse compared to communities from nonaffected areas. Communities of different affected spots were, however, more divergent from each other, compared to those of different nonaffected areas. This indicates a reduced and shifted microbial community composition caused by the black spot disease. Different communities found in black spots likely indicate different stages of the disease. In affected areas, Flavobacteriaceae rose to one of the most abundant and active families due to the increase of Aquimarina spp., suggesting a significant role in shell disease syndrome. We isolated 75 bacterial strains from diseased and healthy areas, which are primarily affiliated with Proteobacteria and Bacteroidetes, reflecting the dominant phyla detected by amplicon sequencing. The ability to degrade chitin was mainly found for Gammaproteobacteria and Aquimarina spp. within the Flavobacteriia, while the ability to use N-acetylglucosamine, the monomer of the polysaccharide chitin, was observed for most isolates, including many Alphaproteobacteria. One-third of the isolates, including most Aquimarina spp., showed antagonistic properties, indicating a high potential for interactions between the bacterial populations. The combination of bacterial community analysis and the physiological properties of the isolates provided insights into a functional complex epibacterial community on the carapace of C. pagurus. IMPORTANCE In recent years, shell disease syndrome has been detected for several ecologically and economically important crustacean species. Large proportions of populations are affected, e.g., >60% of the widely distributed species Cancer pagurus in different North Sea areas. Bacteria play a significant role in the development of different forms of shell disease, all characterized by microbial chitinolytic degradation of the outer shell. By comparing the bacterial communities of healthy and diseased areas of the shell of C. pagurus, we demonstrated that the disease causes a reduced bacterial diversity within affected areas, a phenomenon co-occurring also with many other diseases. Furthermore, the community composition dramatically changed with some taxa rising to high relative abundances and showing increased activity, indicating strong participation in shell disease. Characterization of bacterial isolates obtained from affected and nonaffected spots provided deeper insights into their physiological properties and thus the possible role within the microbiome.
Collapse
Affiliation(s)
- Nils Bergen
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Philipp Krämer
- Institute for Biology and Environmental Science, University of Oldenburg, Oldenburg, Germany
| | - Julia Romberg
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| | - Antje Wichels
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Biologische Anstalt Helgoland, Helgoland, Germany
| | - Gabriele Gerlach
- Institute for Biology and Environmental Science, University of Oldenburg, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Oldenburg, Germany
| | - Thorsten Brinkhoff
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
| |
Collapse
|
9
|
Wilber MQ, DeMarchi J, Fefferman NH, Silk MJ. High prevalence does not necessarily equal maintenance species: Avoiding biased claims of disease reservoirs when using surveillance data. J Anim Ecol 2022; 91:1740-1754. [PMID: 35838341 DOI: 10.1111/1365-2656.13774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/12/2022] [Indexed: 11/30/2022]
Abstract
1. Many pathogens of public health and conservation concern persist in host communities. Identifying candidate maintenance and reservoir species is therefore a central component of disease management. The term maintenance species implies that if all species but the putative maintenance species were removed, then the pathogen would still persist. In the absence of field manipulations, this statement inherently requires a causal or mechanistic model to assess. 2. However, we lack a systematic understanding of i) how often conclusions are made about maintenance and reservoir species without reference to mechanistic models ii) what types of biases may be associated with these conclusions and iii) how explicitly invoking causal or mechanistic modeling can help ameliorate these biases. Filling these knowledge gaps is critical for robust inference on pathogen persistence and spillover in multihost parasite systems, with clear implications for human and wildlife health. 3. To address these gaps, we performed a literature review on the evidence previous studies have used to make claims regarding maintenance or reservoir species. We then developed a multihost-parasite model to explore and demonstrate common biases that could arise when inferring maintenance potential from observational prevalence data. Finally, we developed new theory to show how model-driven inference of maintenance species can minimize and eliminate emergent biases. 4. In our review, we found that 83% of studies used some form of observational prevalence data to draw conclusions on maintenance potential and only 6% of these studies combined observational data with mechanistic modeling. Using our model, we demonstrate how the community, spatial, and temporal context of observational data can lead to substantial biases in inferences of maintenance potential. Importantly, our theory identifies that model-driven inference of maintenance species elucidates other streams of observational data that can be leveraged to correct these biases. 5. Model-driven inference is an essential, yet underused, component of multidisciplinary studies that make inference on host reservoir and maintenance species. Better integration of wildlife disease surveillance and mechanistic models is necessary to improve the robustness and reproducibility of our conclusions regarding maintenance and reservoir species.
Collapse
Affiliation(s)
- Mark Q Wilber
- Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, 37996, Knoxville, TN
| | - Joseph DeMarchi
- Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture, 37996, Knoxville, TN
| | - Nina H Fefferman
- Department Ecology and Evolutionary Biology, University of Tennessee, 37996, Knoxville, TN.,Department of Mathematics, University of Tennessee, 37996, Knoxville, TN
| | - Matthew J Silk
- Department Ecology and Evolutionary Biology, University of Tennessee, 37996, Knoxville, TN
| |
Collapse
|
10
|
Zimmer C, Woods HA, Martin LB. Information theory in vertebrate stress physiology. Trends Endocrinol Metab 2022; 33:8-17. [PMID: 34750063 DOI: 10.1016/j.tem.2021.10.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/01/2021] [Accepted: 10/09/2021] [Indexed: 11/21/2022]
Abstract
Information theory has been applied productively across biology, but it has been used minimally in endocrinology. Here, we advocate for the integration of information theory into stress endocrinology. Presently, the majority of models of stress center on the regulation of hormone concentrations, even though what interests most endocrinologists and matters in terms of individual health and evolutionary fitness is the information content of hormones. In neuroscience, the free energy principle, a concept offered to explain how the brain infers current and future states of the environment, could be a guide for resolving how information is instantiated in hormones such as the glucocorticoids. Here, we offer several ideas and promising options for research addressing how hormones encode and cells respond to information in glucocorticoids.
Collapse
Affiliation(s)
- Cedric Zimmer
- Global Health and Infectious Disease Research Center, University of South Florida, FL 33612, USA; Laboratoire d'Ethologie Expérimentale et Comparée, LEEC, UR 4443, Université Sorbonne Paris Nord, 93430, Villetaneuse, France.
| | - H Arthur Woods
- University of Montana, Division of Biological Sciences, Missoula, MT 59812, USA
| | - Lynn B Martin
- Global Health and Infectious Disease Research Center, University of South Florida, FL 33612, USA
| |
Collapse
|
11
|
Abstract
AbstractTrade-offs and constraints are inherent to life, and studies of these phenomena play a central role in both organismal and evolutionary biology. Trade-offs can be defined, categorized, and studied in at least six, not mutually exclusive, ways. (1) Allocation constraints are caused by a limited resource (e.g., energy, time, space, essential nutrients), such that increasing allocation to one component necessarily requires a decrease in another (if only two components are involved, this is referred to as the Y-model, e.g., energy devoted to size versus number of offspring). (2) Functional conflicts occur when features that enhance performance of one task decrease performance of another (e.g., relative lengths of in-levers and out-levers, force-velocity trade-offs related to muscle fiber type composition). (3) Shared biochemical pathways, often involving integrator molecules (e.g., hormones, neurotransmitters, transcription factors), can simultaneously affect multiple traits, with some effects being beneficial for one or more components of Darwinian fitness (e.g., survival, age at first reproduction, fecundity) and others detrimental. (4) Antagonistic pleiotropy describes genetic variants that increase one component of fitness (or a lower-level trait) while simultaneously decreasing another. (5) Ecological circumstances (or selective regime) may impose trade-offs, such as when foraging behavior increases energy availability yet also decreases survival. (6) Sexual selection may lead to the elaboration of (usually male) secondary sexual characters that improve mating success but handicap survival and/or impose energetic costs that reduce other fitness components. Empirical studies of trade-offs often search for negative correlations between two traits that are the expected outcomes of the trade-offs, but this will generally be inadequate if more than two traits are involved and especially for complex physiological networks of interacting traits. Moreover, trade-offs often occur only in populations that are experiencing harsh environmental conditions or energetic challenges at the extremes of phenotypic distributions, such as among individuals or species that have exceptional athletic abilities. Trade-offs may be (partially) circumvented through various compensatory mechanisms, depending on the timescale involved, ranging from acute to evolutionary. Going forward, a pluralistic view of trade-offs and constraints, combined with integrative analyses that cross levels of biological organization and traditional boundaries among disciplines, will enhance the study of evolutionary organismal biology.
Collapse
|
12
|
Downie AE, Mayer A, Metcalf CJE, Graham AL. Optimal immune specificity at the intersection of host life history and parasite epidemiology. PLoS Comput Biol 2021; 17:e1009714. [PMID: 34932551 PMCID: PMC8730424 DOI: 10.1371/journal.pcbi.1009714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/05/2022] [Accepted: 12/02/2021] [Indexed: 11/30/2022] Open
Abstract
Hosts diverge widely in how, and how well, they defend themselves against infection and immunopathology. Why are hosts so heterogeneous? Both epidemiology and life history are commonly hypothesized to influence host immune strategy, but the relationship between immune strategy and each factor has commonly been investigated in isolation. Here, we show that interactions between life history and epidemiology are crucial for determining optimal immune specificity and sensitivity. We propose a demographically-structured population dynamics model, in which we explore sensitivity and specificity of immune responses when epidemiological risks vary with age. We find that variation in life history traits associated with both reproduction and longevity alters optimal immune strategies-but the magnitude and sometimes even direction of these effects depends on how epidemiological risks vary across life. An especially compelling example that explains previously-puzzling empirical observations is that depending on whether infection risk declines or rises at reproductive maturity, later reproductive maturity can select for either greater or lower immune specificity, potentially illustrating why studies of lifespan and immune variation across taxa have been inconclusive. Thus, the sign of selection on the life history-immune specificity relationship can be reversed in different epidemiological contexts. Drawing on published life history data from a variety of chordate taxa, we generate testable predictions for this facet of the optimal immune strategy. Our results shed light on the causes of the heterogeneity found in immune defenses both within and among species and the ultimate variability of the relationship between life history and immune specificity.
Collapse
Affiliation(s)
- Alexander E. Downie
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Andreas Mayer
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - C. Jessica E. Metcalf
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- School of Public and International Affairs, Princeton University, Princeton, New Jersey, United States of America
| | - Andrea L. Graham
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| |
Collapse
|
13
|
Ruden RM, Adelman JS. Disease tolerance alters host competence in a wild songbird. Biol Lett 2021; 17:20210362. [PMID: 34699737 PMCID: PMC8548076 DOI: 10.1098/rsbl.2021.0362] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/04/2021] [Indexed: 11/12/2022] Open
Abstract
Individuals can express a range of disease phenotypes during infection, with important implications for epidemics. Tolerance, in particular, is a host response that minimizes the per-pathogen fitness costs of infection. Because tolerant hosts show milder clinical signs and higher survival, despite similar pathogen burdens, their potential for prolonged pathogen shedding may facilitate the spread of pathogens. To test this, we simulated outbreaks of mycoplasmal conjunctivitis in house finches, asking how the speed of transmission varied with tissue-specific and behavioural components of tolerance, milder conjunctivitis and anorexia for a given pathogen load, respectively. Because tissue-specific tolerance hinders pathogen deposition onto bird feeders, important transmission hubs, we predicted it would slow transmission. Because behavioural tolerance should increase interactions with bird feeders, we predicted it would speed transmission. Our findings supported these predictions, suggesting that variation in tolerance could help identify individuals most likely to transmit pathogens.
Collapse
Affiliation(s)
- Rachel M. Ruden
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA, USA
- Iowa Department of Natural Resources, Des Moines, IA, USA
| | - James S. Adelman
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA, USA
- Department of Biological Sciences, University of Memphis, Memphis, TN, USA
| |
Collapse
|
14
|
Nunn CL, Vining AQ, Chakraborty D, Reiskind MH, Young HS. Effects of host extinction and vector preferences on vector-borne disease risk in phylogenetically structured host-hector communities. PLoS One 2021; 16:e0256456. [PMID: 34424937 PMCID: PMC8382198 DOI: 10.1371/journal.pone.0256456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/08/2021] [Indexed: 11/26/2022] Open
Abstract
Anthropogenic disturbance impacts the phylogenetic composition and diversity of ecological communities. While changes in diversity are known to dramatically change species interactions and alter disease dynamics, the effects of phylogenetic changes in host and vector communities on disease have been relatively poorly studied. Using a theoretical model, we investigated how phylogeny and extinction influence network structural characteristics relevant to disease transmission in disturbed environments. We modelled a multi-host, multi-vector community as a bipartite ecological network, where nodes represent host and vector species and edges represent connections among them through vector feeding, and we simulated vector preferences and threat status on host and parasite phylogenies. We then simulated loss of hosts, including phylogenetically clustered losses, to investigate how extinction influences network structure. We compared effects of phylogeny and extinction to those of host specificity, which we predicted to strongly increase network modularity and reduce disease prevalence. The simulations revealed that extinction often increased modularity, with higher modularity as species loss increased, although not as much as increasing host specificity did. These results suggest that extinction itself, all else being equal, may reduce disease prevalence in disturbed communities. However, in real communities, systematic patterns in species loss (e.g. favoring high competence species) or changes in abundance may counteract these effects. Unexpectedly, we found that effects of phylogenetic signal in host and vector traits were relatively weak, and only important when phylogenetic signal of host and vector traits were similar, or when these traits both varied.
Collapse
Affiliation(s)
- Charles L. Nunn
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, United States of America
- Duke Global Health Institute, Durham, North Carolina, United States of America
| | - Alexander Q. Vining
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, United States of America
- Graduate Program in Animal Behavior, UC Davis, Davis, California, United States of America
| | - Debapriyo Chakraborty
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, United States of America
- INRAE ENVT IHAP, National Veterinary School of Toulouse, Toulouse, France
| | - Michael H. Reiskind
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Hillary S. Young
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, United States of America
| |
Collapse
|
15
|
Tadiri CP, Fussmann GF, Scott ME. Parasite spread in experimental metapopulations: resistance, tolerance and host competence. OIKOS 2021. [DOI: 10.1111/oik.07837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - Marilyn E. Scott
- Inst. of Parasitology, McGill Univ. Ste. Anne‐de‐Bellevue QC Canada
| |
Collapse
|
16
|
Wolcott KA, Margos G, Fingerle V, Becker NS. Host association of Borrelia burgdorferi sensu lato: A review. Ticks Tick Borne Dis 2021; 12:101766. [PMID: 34161868 DOI: 10.1016/j.ttbdis.2021.101766] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 11/29/2022]
Abstract
Borrelia burgdorferi sensu lato (Bbsl) is a bacterial species complex that includes the etiological agents of the most frequently reported vector-borne disease in the Northern hemisphere, Lyme borreliosis. It currently comprises > 20 named and proposed genospecies that use vertebrate hosts and tick vectors for transmission in the Americas and Eurasia. Host (and vector) associations influence geographic distribution and speciation in Bbsl, which is of particular relevance to human health. To target gaps in knowledge for future efforts to understand broad patterns of the Bbsl-tick-host system and how they relate to human health, the present review aims to give a comprehensive summary of the literature on host association in Bbsl. Of 465 papers consulted (404 after exclusion criteria were applied), 96 sought to experimentally establish reservoir competence of 143 vertebrate host species for Bbsl. We recognize xenodiagnosis as the strongest method used, however it is infrequent (20% of studies) probably due to difficulties in maintaining tick vectors and/or wild host species in the lab. Some well-established associations were not experimentally confirmed according to our definition (ex: Borrelia garinii, Ixodes uriae and sea birds). We conclude that our current knowledge on host association in Bbsl is mostly derived from a subset of host, vector and bacterial species involved, providing an incomplete knowledge of the physiology, ecology and evolutionary history of these interactions. More studies are needed on all host, vector and bacterial species globally involved with a focus on non-rodent hosts and Asian Bbsl complex species, especially with experimental research that uses xenodiagnosis and genomics to analyze existing host associations in different ecosystems.
Collapse
Affiliation(s)
- Katherine A Wolcott
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany; National Museum of Natural History, Smithsonian Institution, Washington, DC, 20560, USA
| | - Gabriele Margos
- National Reference Centre for Borrelia at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764, Oberschleissheim, Germany
| | - Volker Fingerle
- National Reference Centre for Borrelia at the Bavarian Health and Food Safety Authority, Veterinärstr. 2, 85764, Oberschleissheim, Germany
| | - Noémie S Becker
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany.
| |
Collapse
|
17
|
Garrido M, Halle S, Flatau R, Cohen C, Navarro-Castilla Á, Barja I, Hawlena H. The dilution effect behind the scenes: testing the underlying assumptions of its mechanisms through quantifying the long-term dynamics and effects of a pathogen in multiple host species. Proc Biol Sci 2021; 288:20210773. [PMID: 34102894 PMCID: PMC8187991 DOI: 10.1098/rspb.2021.0773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/12/2021] [Indexed: 01/01/2023] Open
Abstract
Disentangling the mechanisms that mediate the relationships between species diversity and disease risk has both theoretical and applied implications. We employed a model system of rodents and their Mycoplasma pathogens, in which an extreme negative diversity-disease relationship was demonstrated, to test the assumptions underlying three mechanisms that may explain this field pattern. Through quantifying the long-term dynamics and effects of the pathogen in its three host species, we estimated the between-host differences in pathogen spreading and transmission potentials, and host recovery potential and vulnerability to infection. The results suggest that one of the hosts is a pathogen amplifier and the other two hosts function as diluters. Considering the similarity in infection success and intensity among hosts, and the failure to detect any pathogen-induced damage, we could not validate the assumption underlying the hypotheses that diluters reduce the overall transmission or increase the mortality of infected hosts in the system. Instead, the results demonstrate that diluters clear the infection faster than amplifiers, supporting the possibility that the addition of diluters to the community may reduce the overall number of infected hosts through this mechanism. This study highlights the contribution of experimental studies that simultaneously explore different aspects of host-pathogen interactions in multiple hosts, in diversity-disease research.
Collapse
Affiliation(s)
- Mario Garrido
- Jacob Blaustein Center for Scientific Cooperation, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Snir Halle
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Ron Flatau
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Carmit Cohen
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Álvaro Navarro-Castilla
- Etho-Physiology Group. Unit of Zoology. Department of Biology. Faculty of Sciences, the Autonomous University of Madrid, Spain
| | - Isabel Barja
- Etho-Physiology Group. Unit of Zoology. Department of Biology. Faculty of Sciences, the Autonomous University of Madrid, Spain
- Center for Research on Biodiversity and Global Change (CIBC-UAM), the Autonomous University of Madrid, Spain
| | - Hadas Hawlena
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| |
Collapse
|
18
|
Halliday FW, Jalo M, Laine AL. The effect of host community functional traits on plant disease risk varies along an elevational gradient. eLife 2021; 10:67340. [PMID: 33983120 PMCID: PMC8208817 DOI: 10.7554/elife.67340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/10/2021] [Indexed: 01/17/2023] Open
Abstract
Quantifying the relative impact of environmental conditions and host community structure on disease is one of the greatest challenges of the 21st century, as both climate and biodiversity are changing at unprecedented rates. Both increasing temperature and shifting host communities toward more fast-paced life-history strategies are predicted to increase disease, yet their independent and interactive effects on disease in natural communities remain unknown. Here, we address this challenge by surveying foliar disease symptoms in 220, 0.5 m-diameter herbaceous plant communities along a 1100-m elevational gradient. We find that increasing temperature associated with lower elevation can increase disease by (1) relaxing constraints on parasite growth and reproduction, (2) determining which host species are present in a given location, and (3) strengthening the positive effect of host community pace-of-life on disease. These results provide the first field evidence, under natural conditions, that environmental gradients can alter how host community structure affects disease. Climate change is causing shifts in the ecology and biodiversity of different world regions at unprecedented rates. Global warming is also linked with changes in the risk for certain infectious diseases in humans, but also in animals and plants. There are several possible mechanisms for this. For one thing, changing weather patterns may affect how pathogens grow and reproduce. For another, the distribution ranges of animal and plant hosts of certain disease-causing pathogens are changing because of global warming. This means that the distributions of pathogens are also changing, and so is the severity of the diseases that they cause. Increasing temperatures may also influence the physiological traits that make host species suitable for pathogens. This is because the traits that allow species to survive or adapt to changes in their environment may also make them better at hosting and transmitting the pathogens that cause disease. For example, in plant communities, rising temperatures could favor species with faster growth rates, quicker reproduction and high dispersal, and these traits are often associated with more efficient spread of disease. Despite a lot of research into the effects of climate, it remains unclear how temperature, pathogen growth and reproduction, and host species’ traits and distributions combine and interact to alter infectious disease risk, especially in wild plant communities. To investigate this, Halliday, Jalo and Laine studied an area in southeast Switzerland where natural temperature and biodiversity change gradually through the region. The aim was to explore how relationships between plant biodiversity, pathogens and disease risk change with temperature, and to understand whether environmental or biological factors influence infectious disease risk more. Halliday, Jalo and Laine measured the levels of fungal diseases found in the leaves of plant communities spanning 1,100 meters of elevation, showing that higher temperatures increase disease risk both directly and indirectly. Directly, higher temperatures increased pathogen growth and reproduction, and indirectly, they influenced which plants were present and therefore able to act as disease hosts. The results also indicated that temperature can affect how the traits of plants drive the transmission rates of fungal pathogens. Important predictors of disease risk were traits relating to the growth rate of host plants, which tended to increase in areas with low elevation where the surface of the soil was warm. This study represents the first analysis, in wild plants, of how changing temperatures, the traits of shifting host species, and resident parasite populations interact to impact infectious disease risk. The insights Halliday, Jalo and Laine provided could aid in predicting how global climate change will influence infectious disease risk.
Collapse
Affiliation(s)
- Fletcher W Halliday
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zurich, Switzerland
| | - Mikko Jalo
- Faculty of Biological and Environmental sciences, University of Helsinki, Helsinki, Finland
| | - Anna-Liisa Laine
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zurich, Switzerland.,Faculty of Biological and Environmental sciences, University of Helsinki, Helsinki, Finland
| |
Collapse
|
19
|
Abstract
Zoonotic diseases are infectious diseases of humans caused by pathogens that are shared between humans and other vertebrate animals. Previously, pristine natural areas with high biodiversity were seen as likely sources of new zoonotic pathogens, suggesting that biodiversity could have negative impacts on human health. At the same time, biodiversity has been recognized as potentially benefiting human health by reducing the transmission of some pathogens that have already established themselves in human populations. These apparently opposing effects of biodiversity in human health may now be reconcilable. Recent research demonstrates that some taxa are much more likely to be zoonotic hosts than others are, and that these animals often proliferate in human-dominated landscapes, increasing the likelihood of spillover. In less-disturbed areas, however, these zoonotic reservoir hosts are less abundant and nonreservoirs predominate. Thus, biodiversity loss appears to increase the risk of human exposure to both new and established zoonotic pathogens. This new synthesis of the effects of biodiversity on zoonotic diseases presents an opportunity to articulate the next generation of research questions that can inform management and policy. Future studies should focus on collecting and analyzing data on the diversity, abundance, and capacity to transmit of the taxa that actually share zoonotic pathogens with us. To predict and prevent future epidemics, researchers should also focus on how these metrics change in response to human impacts on the environment, and how human behaviors can mitigate these effects. Restoration of biodiversity is an important frontier in the management of zoonotic disease risk.
Collapse
|
20
|
Circulation of Babesia Species and Their Exposure to Humans through Ixodes Ricinus. Pathogens 2021; 10:pathogens10040386. [PMID: 33804875 PMCID: PMC8063829 DOI: 10.3390/pathogens10040386] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/15/2021] [Accepted: 03/19/2021] [Indexed: 12/13/2022] Open
Abstract
Human babesiosis in Europe has been attributed to infection with Babesia divergens and, to a lesser extent, with Babesia venatorum and Babesia microti, which are all transmitted to humans through a bite of Ixodes ricinus. These Babesia species circulate in the Netherlands, but autochthonous human babesiosis cases have not been reported so far. To gain more insight into the natural sources of these Babesia species, their presence in reservoir hosts and in I. ricinus was examined. Moreover, part of the ticks were tested for co-infections with other tick borne pathogens. In a cross-sectional study, qPCR-detection was used to determine the presence of Babesia species in 4611 tissue samples from 27 mammalian species and 13 bird species. Reverse line blotting (RLB) and qPCR detection of Babesia species were used to test 25,849 questing I. ricinus. Fragments of the 18S rDNA and cytochrome c oxidase subunit I (COI) gene from PCR-positive isolates were sequenced for confirmation and species identification and species-specific PCR reactions were performed on samples with suspected mixed infections. Babesia microti was found in two widespread rodent species: Myodes glareolus and Apodemus sylvaticus, whereas B. divergens was detected in the geographically restricted Cervus elaphus and Bison bonasus, and occasionally in free-ranging Ovis aries. B. venatorum was detected in the ubiquitous Capreolus capreolus, and occasionally in free-ranging O. aries. Species-specific PCR revealed co-infections in C. capreolus and C. elaphus, resulting in higher prevalence of B. venatorum and B. divergens than disclosed by qPCR detection, followed by 18S rDNA and COI sequencing. The non-zoonotic Babesia species found were Babesia capreoli, Babesia vulpes, Babesia sp. deer clade, and badger-associated Babesia species. The infection rate of zoonotic Babesia species in questing I. ricinus ticks was higher for Babesia clade I (2.6%) than Babesia clade X (1.9%). Co-infection of B. microti with Borrelia burgdorferi sensu lato and Neoehrlichia mikurensis in questing nymphs occurred more than expected, which reflects their mutual reservoir hosts, and suggests the possibility of co-transmission of these three pathogens to humans during a tick bite. The ubiquitous spread and abundance of B. microti and B. venatorum in their reservoir hosts and questing ticks imply some level of human exposure through tick bites. The restricted distribution of the wild reservoir hosts for B. divergens and its low infection rate in ticks might contribute to the absence of reported autochthonous cases of human babesiosis in the Netherlands.
Collapse
|
21
|
Manzoli DE, Saravia-Pietropaolo MJ, Arce SI, Percara A, Antoniazzi LR, Beldomenico PM. Specialist by preference, generalist by need: availability of quality hosts drives parasite choice in a natural multihost-parasite system. Int J Parasitol 2021; 51:527-534. [PMID: 33713648 DOI: 10.1016/j.ijpara.2020.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 11/24/2022]
Abstract
Encountering suitable hosts is key for parasite success. A general assumption for disease transmission is that the contact of a parasite with a potential host is driven by the density or relative frequency of hosts. That assumption ignores the potential role of differential host attractiveness for parasites that can drive the encounter of hosts. It has been posited that hosts may be chosen by parasites as a function of their suitability, but the existing literature addressing that hypothesis is still very scarce. In a natural system involving a parasitic Philornis botfly and its multiple bird hosts, there are profound differences in host quality. The Great Kiskadee tolerates and does not invest in resisting the infection, which makes it an optimal host. Alternative hosts are frequently used, but whilst some of them may be good options, others are bad alternatives. Here we examined the host selection processes that drive parasite dynamics in this system with 8 years of data from a longitudinal study under natural conditions. We found that the use of an alternative host was not driven by its density or relative frequency, but instead selection of these hosts was strongly dependent on availability of more suitable hosts. When optimal hosts are plentiful, the parasite tends to ignore alternative ones. As broods of optimal hosts become limited, good alternative hosts are targeted. The parasite chooses bad alternative hosts only when better alternatives are not sufficiently available. These results add evidence from a natural system that some parasites choose their hosts as a function of their profitability, and show that host selection by this parasite is plastic and context-dependent. Such findings could have important implications for the epidemiology of some parasitic and vector-borne infections which should be considered when modelling and managing those diseases. The facultative host selection observed here can be of high relevance for public health, animal husbandry, and biodiversity conservation, because reductions in the richness of hosts might cause humans, domestic animals, or endangered species to become increasingly targeted by parasites that can drive the encounter of hosts.
Collapse
Affiliation(s)
- Darío Ezequiel Manzoli
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina; Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, RP Kreder 2805, 3080 Esperanza, Santa Fe, Argentina
| | - María José Saravia-Pietropaolo
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina
| | - Sofía Irene Arce
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina
| | - Alejandro Percara
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina
| | - Leandro Raúl Antoniazzi
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina
| | - Pablo Martín Beldomenico
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas), Argentina; Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, RP Kreder 2805, 3080 Esperanza, Santa Fe, Argentina.
| |
Collapse
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Ohmer MEB, Costantini D, Czirják GÁ, Downs CJ, Ferguson LV, Flies A, Franklin CE, Kayigwe AN, Knutie S, Richards-Zawacki CL, Cramp RL. Applied ecoimmunology: using immunological tools to improve conservation efforts in a changing world. CONSERVATION PHYSIOLOGY 2021; 9:coab074. [PMID: 34512994 PMCID: PMC8422949 DOI: 10.1093/conphys/coab074] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/27/2021] [Accepted: 08/09/2021] [Indexed: 05/11/2023]
Abstract
Ecoimmunology is a rapidly developing field that explores how the environment shapes immune function, which in turn influences host-parasite relationships and disease outcomes. Host immune defence is a key fitness determinant because it underlies the capacity of animals to resist or tolerate potential infections. Importantly, immune function can be suppressed, depressed, reconfigured or stimulated by exposure to rapidly changing environmental drivers like temperature, pollutants and food availability. Thus, hosts may experience trade-offs resulting from altered investment in immune function under environmental stressors. As such, approaches in ecoimmunology can provide powerful tools to assist in the conservation of wildlife. Here, we provide case studies that explore the diverse ways that ecoimmunology can inform and advance conservation efforts, from understanding how Galapagos finches will fare with introduced parasites, to using methods from human oncology to design vaccines against a transmissible cancer in Tasmanian devils. In addition, we discuss the future of ecoimmunology and present 10 questions that can help guide this emerging field to better inform conservation decisions and biodiversity protection. From better linking changes in immune function to disease outcomes under different environmental conditions, to understanding how individual variation contributes to disease dynamics in wild populations, there is immense potential for ecoimmunology to inform the conservation of imperilled hosts in the face of new and re-emerging pathogens, in addition to improving the detection and management of emerging potential zoonoses.
Collapse
Affiliation(s)
- Michel E B Ohmer
- Living Earth Collaborative, Washington University in St. Louis, MO 63130, USA
| | - David Costantini
- Unité Physiologie Moléculaire et Adaptation (PhyMA), Muséum National d’Histoire Naturelle, CNRS, 57 Rue Cuvier, CP32, 75005, Paris, France
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - Cynthia J Downs
- Department of Environmental Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Laura V Ferguson
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Andy Flies
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
| | - Ahab N Kayigwe
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Sarah Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06268, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, CT 06268, USA
| | | | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
- Corresponding author: School of Biological Sciences, The University of Queensland, Queensland 4072, Australia.
| |
Collapse
|
24
|
Life history and population regulation shape demographic competence and influence the maintenance of endemic disease. Nat Ecol Evol 2020; 5:82-91. [PMID: 33168996 DOI: 10.1038/s41559-020-01333-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 09/23/2020] [Indexed: 11/09/2022]
Abstract
Host life history and demography play important roles in host-pathogen dynamics, by influencing the ability of hosts and their pathogens to coexist. We introduce the concept of demographic competence to describe the ability of host populations to sustain endemic infectious disease. Hosts with high demographic competence are more likely to act as keystone hosts and constitute reservoirs of infection that can spill over into other species. We propose that the pace of host life history will interact with pathogen life history to influence demographic competence. Our models demonstrate that slow-living hosts (with high survival and low recruitment rates) have greater demographic competence than fast-living hosts (with low survival and high recruitment rates) for susceptible-infected disease dynamics, although this difference is reduced when populations of slow hosts are age structured. Demographic competence is generally greater among hosts with populations regulated by survival compared to reproduction, but this difference is smallest among slow life histories and reversed for some pathogens with frequency-dependent transmission. An association between pathogen life history traits and the demographic competence of faster-living hosts also has implications for trade-offs between pathogen virulence and transmissibility. Overall, we demonstrate how host life history traits can help predict wildlife reservoirs of zoonoses and the vulnerability of populations to disease-induced extinction.
Collapse
|
25
|
Zimmer C, Hanson HE, Wildman DE, Uddin M, Martin LB. FKBP5: A Key Mediator of How Vertebrates Flexibly Cope with Adversity. Bioscience 2020. [DOI: 10.1093/biosci/biaa114] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Abstract
Flexibility in the regulation of the hypothalamic–pituitary–adrenal (HPA) axis is an important mediator of stress resilience as it helps organisms adjust to, avoid, or compensate for acute and chronic challenges across changing environmental contexts. Glucocorticoids remain the favorite metric from medicine to conservation biology to attempt to quantify stress resilience despite the skepticism around their consistency in relation to individual health, welfare, and fitness. We suggest that a cochaperone molecule related to heat shock proteins and involved in glucocorticoid receptor activity, FKBP5, may mediate HPA flexibility and therefore stress resilience because it affects how individuals can regulate glucocorticoids and therefore capacitates their abilities to adjust phenotypes appropriately to prevailing, adverse conditions. Although the molecule is well studied in the biomedical literature, FKBP5 research in wild vertebrates is limited. In the present article, we highlight the potential major role of FKBP5 as mediator of HPA axis flexibility in response to adversity in humans and lab rodents.
Collapse
Affiliation(s)
- Cedric Zimmer
- Global and Planetary Health Department of the College of Public Health, University of South Florida, Tampa, Florida
| | - Haley E Hanson
- Global and Planetary Health Department of the College of Public Health, University of South Florida, Tampa, Florida
| | - Derek E Wildman
- Global and Planetary Health Department of the College of Public Health, University of South Florida, Tampa, Florida
| | - Monica Uddin
- Global and Planetary Health Department of the College of Public Health, University of South Florida, Tampa, Florida
| | - Lynn B Martin
- Global and Planetary Health Department of the College of Public Health, University of South Florida, Tampa, Florida
| |
Collapse
|
26
|
Welsh ME, Cronin JP, Mitchell CE. Trait-based variation in host contribution to pathogen transmission across species and resource supplies. Ecology 2020; 101:e03164. [PMID: 33460129 DOI: 10.1002/ecy.3164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/24/2020] [Accepted: 06/18/2020] [Indexed: 01/26/2023]
Abstract
Two key knowledge gaps currently limit the development of more predictive and general models of pathogen transmission: (1) the physiological basis of heterogeneity in host contribution to pathogen transmission (reservoir potential) remains poorly understood and (2) a general means of integrating the ecological dynamics of host communities has yet to emerge. If the traits responsible for differences in reservoir potential also modulate host community dynamics, these traits could be used to predict pathogen transmission as host communities change. In two greenhouse experiments, across 23 host species and two levels of resource supply, the reservoir potential of plant hosts increased significantly along the Leaf Economics Spectrum, a global axis of plant physiological trait covariation that features prominently in models of plant community ecology. This indicates that the traits of the Leaf Economics Spectrum underlie broad differences in reservoir potential across host species and resource supplies. Therefore, host traits could be used to integrate epidemiological models of pathogen transmission with ecological models of host community change.
Collapse
Affiliation(s)
- Miranda E Welsh
- Thompson Writing Program, Duke University, Durham, North Carolina, 27708, USA.,Environment, Ecology and Energy Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - James Patrick Cronin
- U.S. Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Boulevard, Lafayette, Louisiana, 70506, USA
| | - Charles E Mitchell
- Environment, Ecology and Energy Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA.,Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| |
Collapse
|
27
|
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.
Collapse
|
28
|
Meguro N, Kishida O, Utsumi S, Niwa S, Igarashi S, Kozuka C, Naniwa A, Sato T. Host phenologies and the life history of horsehair worms (Nematomorpha, Gordiida) in a mountain stream in northern Japan. Ecol Res 2020. [DOI: 10.1111/1440-1703.12122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Nanoko Meguro
- Department of Biology, Graduate School of Science Kobe University Kobe Japan
| | - Osamu Kishida
- Tomakomai Experimental Forest, Field Science Center for Northern Biosphere Hokkaido University Tomakomai Japan
| | - Shunsuke Utsumi
- Uryu Experimental Forest, Field Science Center for Northern Biosphere Hokkaido University Horokanai Japan
| | - Shigeru Niwa
- Tomakomai Experimental Forest, Japan Wildlife Research Center Hokkaido University Tomakomai Japan
| | - Susumu Igarashi
- Tomakomai Experimental Forest, Field Science Center for Northern Biosphere Hokkaido University Tomakomai Japan
| | - Chikara Kozuka
- Uryu Experimental Forest, Field Science Center for Northern Biosphere Hokkaido University Horokanai Japan
| | - Aiko Naniwa
- Uryu Experimental Forest, Field Science Center for Northern Biosphere Hokkaido University Horokanai Japan
| | - Takuya Sato
- Department of Biology, Graduate School of Science Kobe University Kobe Japan
| |
Collapse
|
29
|
Schoenle LA, Moore IT, Dudek AM, Garcia EB, Mays M, Haussmann MF, Cimini D, Bonier F. Exogenous glucocorticoids amplify the costs of infection by reducing resistance and tolerance, but effects are mitigated by co-infection. Proc Biol Sci 2020; 286:20182913. [PMID: 30966992 DOI: 10.1098/rspb.2018.2913] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Individual variation in parasite defences, such as resistance and tolerance, can underlie heterogeneity in fitness and could influence disease transmission dynamics. Glucocorticoid hormone concentrations often change in response to fluctuating environmental conditions and mediate changes in immune function, resource allocation and tissue repair. Thus, changes in glucocorticoid hormone concentrations might mediate individual variation in investment in resistance versus tolerance. In this study, we experimentally increased glucocorticoid concentrations in red-winged blackbirds ( Agelaius phoeniceus) that were naturally infected with haemosporidian parasites, and assessed changes in resistance and tolerance of infection. Glucocorticoid treatment increased burdens of Plasmodium, the parasite causing avian malaria, but only in the absence of co-infection with another Haemosporidian, Haemoproteus. Thus, glucocorticoids might reduce resistance to infection, but co-infection can mitigate the negative consequences of increased hormone concentrations. Glucocorticoid treatment also decreased tolerance of infection. We found no evidence that the inflammatory immune response or rate of red blood cell production underlie the effects of glucocorticoids on resistance and tolerance. Our findings suggest that exogenous glucocorticoids can increase the costs of haemosporidian infections by both increasing parasite numbers and reducing an individual's ability to cope with infection. These effects could scale up to impact populations of both host and parasite.
Collapse
Affiliation(s)
- Laura A Schoenle
- 1 Office of Undergraduate Biology, Cornell University , Ithaca, NY , USA.,2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Ignacio T Moore
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Alana M Dudek
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Ellen B Garcia
- 3 Department of Biological Sciences and Biocomplexity Institute, Virginia Tech , Blacksburg, VA , USA
| | - Morgan Mays
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Mark F Haussmann
- 4 Department of Biology, Bucknell University , Lewisburg, PA , USA
| | - Daniela Cimini
- 3 Department of Biological Sciences and Biocomplexity Institute, Virginia Tech , Blacksburg, VA , USA
| | - Frances Bonier
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA.,5 Biology Department, Queen's University , Kingston, Ontario , Canada
| |
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
Henschen AE, Adelman JS. What Does Tolerance Mean for Animal Disease Dynamics When Pathology Enhances Transmission? Integr Comp Biol 2020; 59:1220-1230. [PMID: 31141137 DOI: 10.1093/icb/icz065] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Host competence, or how well an individual transmits pathogens, varies substantially within and among animal populations. As this variation can alter the course of epidemics and epizootics, revealing its underlying causes will help predict and control the spread of disease. One host trait that could drive heterogeneity in competence is host tolerance, which minimizes fitness losses during infection without decreasing pathogen load. In many cases, tolerance should increase competence by extending infectious periods and enabling behaviors that facilitate contact among hosts. However, we argue that the links between tolerance and competence are more varied. Specifically, the different physiological and behavioral mechanisms by which hosts achieve tolerance should have a range of effects on competence, enhancing the ability to transmit pathogens in some circumstances and impeding it in others. Because tissue-based pathology (damage) that reduces host fitness is often critical for pathogen transmission, we focus on two mechanisms that can underlie tolerance at the tissue level: damage-avoidance and damage-repair. As damage-avoidance reduces transmission-enhancing pathology, this mechanism is likely to decrease host competence and pathogen transmission. In contrast, damage-repair does not prevent transmission-relevant pathology from occurring. Rather, damage-repair provides new, healthy tissues that pathogens can exploit, likely extending the infectious period and increasing host competence. We explore these concepts through graphical models and present three disease systems in which damage-avoidance and damage-repair alter host competence in the predicted directions. Finally, we suggest that by incorporating these links, future theoretical studies could provide new insights into infectious disease dynamics and host-pathogen coevolution.
Collapse
Affiliation(s)
- Amberleigh E Henschen
- Department of Natural Resource Ecology and Management, Iowa State University, 339 Science Hall II, 2310 Pammel Drive, Ames, IA 50011, USA
| | - James S Adelman
- Department of Natural Resource Ecology and Management, Iowa State University, 339 Science Hall II, 2310 Pammel Drive, Ames, IA 50011, USA
| |
Collapse
|
32
|
Solak HM, Yanchukov A, Çolak F, Matur F, Sözen M, Ayanoğlu İC, Winternitz JC. Altitudinal Effects on Innate Immune Response of a Subterranean Rodent. Zoolog Sci 2020; 37:31-41. [PMID: 32068372 DOI: 10.2108/zs190067] [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: 05/09/2019] [Accepted: 08/27/2019] [Indexed: 11/17/2022]
Abstract
Immune defense is costly to maintain and deploy, and the optimal investment into immune defense depends on risk of infection. Altitude is a natural environmental factor that is predicted to affect parasite abundance, with lower parasite abundance predicted at higher altitudes due to stronger environmental stressors, which reduce parasite transmission. Using high and low altitude populations of the Turkish blind mole-rat (TBMR) Nannospalax xanthodon, we tested for effects of altitude on constitutive innate immune defense. Field studies were performed with 32 wild animals in 2017 and 2018 from two low- and one high-altitude localities in the Central Taurus Mountains, at respective altitudes of 1010 m, 1115 m, and 2900 m above sea level. We first compared innate standing immune defense as measured by the bacteria-killing ability of blood serum. We then measured corticosterone stress hormone levels, as stressful conditions may affect immune response. Finally, we compared prevalence and intensity of gastrointestinal parasites of field-captured TBMR. We found that the bacteria-killing ability of serum is greater in the mole-rat samples from high altitude. There was no significant difference in stress (corticosterone) levels between altitude categories. Coccidian prevalence and abundance were significantly higher in 2017 than 2018 samples, but there was no significant difference in prevalence, abundance, or intensity between altitudes, or between sexes. Small sample sizes may have reduced power to detect true differences; nevertheless, this study provides support that greater standing innate immunity in high altitude animals may reflect greater investment into constitutive defense.
Collapse
Affiliation(s)
- Halil Mert Solak
- Department of Biology, Faculty of Arts and Science, Bülent Ecevit University, Farabi Campus, 67100, İncivez, Zonguldak, Turkey
| | - Alexey Yanchukov
- Department of Biology, Faculty of Arts and Science, Bülent Ecevit University, Farabi Campus, 67100, İncivez, Zonguldak, Turkey
| | - Faruk Çolak
- Department of Biology, Faculty of Arts and Science, Bülent Ecevit University, Farabi Campus, 67100, İncivez, Zonguldak, Turkey
| | - Ferhat Matur
- Department of Biology, Faculty of Science, Dokuz Eylül University, Tınaztepe Campus, 35390, Buca, İzmir, Turkey
| | - Mustafa Sözen
- Department of Biology, Faculty of Arts and Science, Bülent Ecevit University, Farabi Campus, 67100, İncivez, Zonguldak, Turkey
| | - İhsan Cihan Ayanoğlu
- Department of Biological Sciences, Faculty of Arts and Science, Middle East Technical University, 06800 Çankaya, Ankara, Turkey
| | - Jamie C Winternitz
- Department of Animal Behavior, Bielefeld University, Morgenbreede 45, 33615 Bielefeld, Germany,
| |
Collapse
|
33
|
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.
Collapse
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
| |
Collapse
|
34
|
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.
Collapse
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
| |
Collapse
|
35
|
Hofmeester TR, Bügel EJ, Hendrikx B, Maas M, Franssen FFJ, Sprong H, Matson KD. Parasite Load and Site-Specific Parasite Pressure as Determinants of Immune Indices in Two Sympatric Rodent Species. Animals (Basel) 2019; 9:ani9121015. [PMID: 31766647 PMCID: PMC6940963 DOI: 10.3390/ani9121015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/15/2019] [Accepted: 11/20/2019] [Indexed: 01/04/2023] Open
Abstract
Wildlife is exposed to parasites from the environment. This parasite pressure, which differs among areas, likely shapes the immunological strategies of animals. Individuals differ in the number of parasites they encounter and host, and this parasite load also influences the immune system. The relative impact of parasite pressure vs. parasite load on different host species, particularly those implicated as important reservoirs of zoonotic pathogens, is poorly understood. We captured bank voles (Myodes glareolus) and wood mice (Apodemus sylvaticus) at four sites in the Netherlands. We sampled sub-adult males to quantify their immune function, infestation load for ecto- and gastrointestinal parasites, and infection status for vector-borne microparasites. We then used regression trees to test if variation in immune indices could be explained by among-site differences (parasite pressure), among-individual differences in infestation intensity and infection status (parasite load), or other intrinsic factors. Regression trees revealed splits among sites for haptoglobin, hemagglutination, and body-mass corrected spleen size. We also found splits based on infection/infestation for haptoglobin, hemolysis, and neutrophil to lymphocyte ratio. Furthermore, we found a split between species for hemolysis and splits based on body mass for haptoglobin, hemagglutination, hematocrit, and body-mass corrected spleen size. Our results suggest that both parasite pressure and parasite load influence the immune system of wild rodents. Additional studies linking disease ecology and ecological immunology are needed to understand better the complexities of host-parasite interactions and how these interactions shape zoonotic disease risk.
Collapse
Affiliation(s)
- Tim R. Hofmeester
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands; (T.R.H.); (E.J.B.); (B.H.)
| | - Esther J. Bügel
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands; (T.R.H.); (E.J.B.); (B.H.)
| | - Bob Hendrikx
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands; (T.R.H.); (E.J.B.); (B.H.)
| | - Miriam Maas
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands; (M.M.); (F.F.J.F.); (H.S.)
| | - Frits F. J. Franssen
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands; (M.M.); (F.F.J.F.); (H.S.)
| | - Hein Sprong
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands; (M.M.); (F.F.J.F.); (H.S.)
| | - Kevin D. Matson
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708PB Wageningen, The Netherlands; (T.R.H.); (E.J.B.); (B.H.)
- Correspondence:
| |
Collapse
|
36
|
Kernbach ME, Newhouse DJ, Miller JM, Hall RJ, Gibbons J, Oberstaller J, Selechnik D, Jiang RHY, Unnasch TR, Balakrishnan CN, Martin LB. Light pollution increases West Nile virus competence of a ubiquitous passerine reservoir species. Proc Biol Sci 2019; 286:20191051. [PMID: 31337318 PMCID: PMC6661335 DOI: 10.1098/rspb.2019.1051] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 06/02/2019] [Indexed: 02/06/2023] Open
Abstract
Among the many anthropogenic changes that impact humans and wildlife, one of the most pervasive but least understood is light pollution. Although detrimental physiological and behavioural effects resulting from exposure to light at night are widely appreciated, the impacts of light pollution on infectious disease risk have not been studied. Here, we demonstrate that artificial light at night (ALAN) extends the infectious-to-vector period of the house sparrow (Passer domesticus), an urban-dwelling avian reservoir host of West Nile virus (WNV). Sparrows exposed to ALAN maintained transmissible viral titres for 2 days longer than controls but did not experience greater WNV-induced mortality during this window. Transcriptionally, ALAN altered the expression of gene regulatory networks including key hubs (OASL, PLBD1 and TRAP1) and effector genes known to affect WNV dissemination (SOCS). Despite mounting anti-viral immune responses earlier, transcriptomic signatures indicated that ALAN-exposed individuals probably experienced pathogen-induced damage and immunopathology, potentially due to evasion of immune effectors. A simple mathematical modelling exercise indicated that ALAN-induced increases of host infectious-to-vector period could increase WNV outbreak potential by approximately 41%. ALAN probably affects other host and vector traits relevant to transmission, and additional research is needed to advise the management of zoonotic diseases in light-polluted areas.
Collapse
Affiliation(s)
- Meredith E. Kernbach
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, FL 33620, USA
| | - Daniel J. Newhouse
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Jeanette M. Miller
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, FL 33620, USA
| | - Richard J. Hall
- Center for the Ecology of Infectious Diseases, Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Justin Gibbons
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, FL 33620, USA
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33620, USA
| | - Jenna Oberstaller
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, FL 33620, USA
| | - Daniel Selechnik
- School of Life and Environmental Sciences (SOLES), University of Sydney, Sydney 2006, Australia
| | - Rays H. Y. Jiang
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, FL 33620, USA
| | - Thomas R. Unnasch
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, FL 33620, USA
| | | | - Lynn B. Martin
- Center for Global Health Infectious Disease Research, University of South Florida, Tampa, FL 33620, USA
| |
Collapse
|
37
|
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.
Collapse
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
| |
Collapse
|
38
|
Kernbach ME, Hall RJ, Burkett-Cadena ND, Unnasch TR, Martin LB. Dim light at night: physiological effects and ecological consequences for infectious disease. Integr Comp Biol 2019; 58:995-1007. [PMID: 29939262 DOI: 10.1093/icb/icy080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Light pollution has emerged as a pervasive component of land development over the past century. Several detrimental impacts of this anthropogenic influence have been identified in night shift workers, laboratory rodents, and a plethora of wildlife species. Circadian, or daily, patterns are interrupted by the presence of light at night and have the capacity to alter rhythmic physiological or behavioral characteristics. Indeed, biorhythm disruption can lead to metabolic, reproductive, and immunological dysfunction depending on the intensity, timing, duration, and wavelength of light exposure. Light pollution, in many forms and by many pathways, is thus apt to affect the nature of host-pathogen interactions. However, no research has yet investigated this possibility. The goal of this manuscript is to outline how dim light at night, a relevant and common form of light pollution, may affect disease dynamics by interrupting circadian rhythms and regulation of immune responses as well as opportunities for host-parasite interactions and subsequent transmission risk including spillover into humans. We close by proposing some promising interventions including alternative lighting methods or vector control efforts.
Collapse
Affiliation(s)
| | - Richard J Hall
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | | | - Thomas R Unnasch
- Department of Global Health, University of South Florida, Tampa, FL, USA
| | - Lynn B Martin
- Department of Global Health, University of South Florida, Tampa, FL, USA
| |
Collapse
|
39
|
Martin LB, Vitousek M, Donald JW, Flock T, Fuxjager MJ, Goymann W, Hau M, Husak J, Johnson MA, Kircher B, Knapp R, Miller ET, Schoenle LA, Williams T, Francis CD. IUCN Conservation Status Does Not Predict Glucocorticoid Concentrations in Reptiles and Birds. Integr Comp Biol 2019; 58:800-813. [PMID: 30052988 DOI: 10.1093/icb/icy102] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Circulating glucocorticoids (GCs) are the most commonly used biomarkers of stress in wildlife. However, their utility as a tool for identifying and/or managing at-risk species has varied. Here, we took a very broad approach to conservation physiology, asking whether International Union for the Conservation of Nature (IUCN) listing status (concern versus no obvious concern) and/or location within a geographic range (edge versus non-edge) predicted baseline and post-restraint concentrations of corticosterone (CORT) among many species of birds and reptiles. Even though such an approach can be viewed as coarse, we asked in this analysis whether CORT concentrations might be useful to implicate species at risk. Indeed, our effort, relying on HormoneBase, a repository of data on wildlife steroids, complements several other large-scale efforts in this issue to describe and understand GC variation. Using a phylogenetically informed Bayesian approach, we found little evidence that either IUCN status or edge/non-edge location in a geographic distribution were related to GC levels. However, we did confirm patterns described in previous studies, namely that breeding condition and evolutionary relatedness among species predicted some GC variation. Given the broad scope of our work, we are reluctant to conclude that IUCN status and location within a range are unrelated to GC regulation. We encourage future more targeted efforts on GCs in at-risk populations to reveal how factors leading to IUCN listing or the environmental conditions at range edges impact individual performance and fitness, particularly in the mammals, amphibians, and fish species we could not study here because data are currently unavailable.
Collapse
Affiliation(s)
- Lynn B Martin
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | - Maren Vitousek
- Cornell Lab of Ornithology, Ithaca, NY 14850, USA.,Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jeremy W Donald
- Coates Library, Trinity University, San Antonio, TX 78212, USA
| | - Travis Flock
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Matthew J Fuxjager
- Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA
| | | | - Michaela Hau
- Max Planck Institute for Ornithology, 82319 Starnberg, Germany.,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Jerry Husak
- Department of Biology, University of St. Thomas, St. Paul, MN 55105, USA
| | - Michele A Johnson
- Department of Biology, Trinity University, San Antonio, TX 78212, USA
| | - Bonnie Kircher
- Department of Biology, University of Florida, Gainesville, FL 32608, USA
| | - Rosemary Knapp
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | | | - Laura A Schoenle
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA.,Department of Biology, Hamilton College, Clinton, NY 13323, USA
| | - Tony Williams
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Clinton D Francis
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| |
Collapse
|
40
|
Genospecies of Borrelia burgdorferi sensu lato detected in 16 mammal species and questing ticks from northern Europe. Sci Rep 2019; 9:5088. [PMID: 30911054 PMCID: PMC6434031 DOI: 10.1038/s41598-019-41686-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 03/14/2019] [Indexed: 12/30/2022] Open
Abstract
Lyme borreliosis is the most common vector-borne zoonosis in the northern hemisphere, and the pathogens causing Lyme borreliosis have distinct, incompletely described transmission cycles involving multiple host groups. The mammal community in Fennoscandia differs from continental Europe, and we have limited data on potential competent and incompetent hosts of the different genospecies of Borrelia burgdorferi sensu lato (sl) at the northern distribution ranges where Lyme borreliosis is emerging. We used qPCR to determine presence of B. burgdorferi sl in tissue samples (ear) from 16 mammalian species and questing ticks from Norway, and we sequenced the 5S-23 S rDNA intergenic spacer region to determine genospecies from 1449 qPCR-positive isolates obtaining 423 sequences. All infections coming from small rodents and shrews were linked to the genospecies B. afzelii, while B. burgdorferi sensu stricto (ss) was only found in red squirrels (Sciurus vulgaris). Red squirrels were also infected with B. afzelii and B. garinii. There was no evidence of B. burgdorferi sl infection in moose (Alces alces), red deer (Cervus elaphus) or roe deer (Capreolus capreolus), confirming the role of cervids as incompetent hosts. In infected questing ticks in the two western counties, B. afzelii (67% and 75%) dominated over B. garinii (27% and 21%) and with only a few recorded B. burgdorferi ss and B. valaisiana. B. burgdorferi ss were more common in adult ticks than in nymphs, consistent with a reservoir in squirrels. Our study identifies potential competent hosts for the different genospecies, which is key to understand transmission cycles at high latitudes of Europe.
Collapse
|
41
|
Burgan SC, Gervasi SS, Johnson LR, Martin LB. How Individual Variation in Host Tolerance Affects Competence to Transmit Parasites. Physiol Biochem Zool 2019; 92:49-57. [PMID: 30481116 DOI: 10.1086/701169] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Tolerance, or the maintenance of host health or fitness at a given parasite burden, has often been studied in evolutionary and medical contexts, particularly with respect to effects on the evolution of parasite virulence and individual patient outcomes. These bodies of work have provided insight about tolerance for evolutionary phenomena (e.g., virulence) and individual health (e.g., recovering from an infection). However, due to the specific motivations of that work, few studies have considered the ecological ramifications of variation in tolerance, namely, how variation in forms of tolerance could mediate parasite movement through populations and even community-level disease dynamics. Tolerance is most commonly regarded as the relationship between host fitness and parasite burden. However, few if any studies have actually quantified host fitness, instead utilizing proxies of fitness as the response variables to be regressed against parasite burden. Here, we address how attention to the effects of parasite burden on traits that are relevant to host competence (i.e., the ability to amplify parasites to levels transmissible to other hosts/vectors) will enhance our understanding of disease dynamics in nature. We also provide several forms of guidance for how to overcome the challenges of quantifying tolerance in wild organisms.
Collapse
|
42
|
Altizer S, Becker DJ, Epstein JH, Forbes KM, Gillespie TR, Hall RJ, Hawley DM, Hernandez SM, Martin LB, Plowright RK, Satterfield DA, Streicker DG. Food for contagion: synthesis and future directions for studying host-parasite responses to resource shifts in anthropogenic environments. Philos Trans R Soc Lond B Biol Sci 2019. [PMID: 29531154 DOI: 10.1098/rstb.2017.0102] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Human-provided resource subsidies for wildlife are diverse, common and have profound consequences for wildlife-pathogen interactions, as demonstrated by papers in this themed issue spanning empirical, theoretical and management perspectives from a range of study systems. Contributions cut across scales of organization, from the within-host dynamics of immune function, to population-level impacts on parasite transmission, to landscape- and regional-scale patterns of infection. In this concluding paper, we identify common threads and key findings from author contributions, including the consequences of resource subsidies for (i) host immunity; (ii) animal aggregation and contact rates; (iii) host movement and landscape-level infection patterns; and (iv) interspecific contacts and cross-species transmission. Exciting avenues for future work include studies that integrate mechanistic modelling and empirical approaches to better explore cross-scale processes, and experimental manipulations of food resources to quantify host and pathogen responses. Work is also needed to examine evolutionary responses to provisioning, and ask how diet-altered changes to the host microbiome influence infection processes. Given the massive public health and conservation implications of anthropogenic resource shifts, we end by underscoring the need for practical recommendations to manage supplemental feeding practices, limit human-wildlife conflicts over shared food resources and reduce cross-species transmission risks, including to humans.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
Collapse
Affiliation(s)
- Sonia Altizer
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA .,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Daniel J Becker
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | | | - Kristian M Forbes
- Department of Virology, University of Helsinki, Helsinki, Finland.,Department of Biology, The Pennsylvania State University, University Park, PA, USA.,Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, USA
| | - Thomas R Gillespie
- Department of Environmental Sciences and Program in Population Biology, Ecology and Evolution, Rollins School of Public Health, Emory University, Atlanta, GA, USA.,Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Richard J Hall
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Infectious Disease, College of Veterinary Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Dana M Hawley
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Sonia M Hernandez
- Warnell School of Forestry and Natural Resources, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Lynn B Martin
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Dara A Satterfield
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC 20008, USA
| | - Daniel G Streicker
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK.,MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| |
Collapse
|
43
|
Martin LB, Addison B, Bean AGD, Buchanan KL, Crino OL, Eastwood JR, Flies AS, Hamede R, Hill GE, Klaassen M, Koch RE, Martens JM, Napolitano C, Narayan EJ, Peacock L, Peel AJ, Peters A, Raven N, Risely A, Roast MJ, Rollins LA, Ruiz-Aravena M, Selechnik D, Stokes HS, Ujvari B, Grogan LF. Extreme Competence: Keystone Hosts of Infections. Trends Ecol Evol 2019; 34:303-314. [PMID: 30704782 PMCID: PMC7114649 DOI: 10.1016/j.tree.2018.12.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/10/2018] [Accepted: 12/13/2018] [Indexed: 12/20/2022]
Abstract
Individual hosts differ extensively in their competence for parasites, but traditional research has discounted this variation, partly because modeling such heterogeneity is difficult. This discounting has diminished as tools have improved and recognition has grown that some hosts, the extremely competent, can have exceptional impacts on disease dynamics. Most prominent among these hosts are the superspreaders, but other forms of extreme competence (EC) exist and others await discovery; each with potentially strong but distinct implications for disease emergence and spread. Here, we propose a framework for the study and discovery of EC, suitable for different host-parasite systems, which we hope enhances our understanding of how parasites circulate and evolve in host communities.
Collapse
Affiliation(s)
- Lynn B Martin
- Global and Planetary Health, University of South Florida, Tampa, Florida 33620, USA.
| | - BriAnne Addison
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Andrew G D Bean
- CSIRO Health & Biosecurity at the Australian Animal Health Laboratory, Geelong, VIC 3220, Australia
| | - Katherine L Buchanan
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Ondi L Crino
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Justin R Eastwood
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Andrew S Flies
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7008, Australia
| | - Rodrigo Hamede
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Marcel Klaassen
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Rebecca E Koch
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Johanne M Martens
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | | | - Edward J Narayan
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia
| | - Lee Peacock
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Alison J Peel
- Environmental Futures Research Institute, Griffith University, Nathan, QLD 4111, Australia
| | - Anne Peters
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Nynke Raven
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Alice Risely
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Michael J Roast
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Lee A Rollins
- School of Biological, Earth and Environmental Sciences, Evolution & Ecology Research Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Manuel Ruiz-Aravena
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Dan Selechnik
- School of Life and Environmental Sciences (SOLES), University of Sydney, Sydney, NSW 2006, Australia
| | - Helena S Stokes
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Beata Ujvari
- School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds, VIC 3216, Australia
| | - Laura F Grogan
- Environmental Futures Research Institute, Griffith University, Nathan, QLD 4111, Australia
| |
Collapse
|
44
|
Simulated viral infection in early-life alters brain morphology, activity and behavior in zebra finches (Taeniopygia guttata). Physiol Behav 2018; 196:36-46. [PMID: 30134141 DOI: 10.1016/j.physbeh.2018.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 08/16/2018] [Accepted: 08/16/2018] [Indexed: 01/24/2023]
Abstract
Early-life immune challenges (ELIC) have long-term effects on adult behavior and brain development. ELIC studies on birds are still few, but they are epidemiologically crucial since birds are important hosts of many mosquito-borne viruses. In this study, we administered a viral infection mimicking agent, Polyinosinic: polycytidylic acid (Poly I:C), to nestling zebra finches on post-hatch day 14. When birds became sexually mature, their general activity (i.e., hopping, feeding behavior) and mosquito defense behaviors (i.e., hops, head movements, pecks, wing movements, foot movements, and scratches) were measured. Following behavioral trials, brains of male birds were collected for anatomical and histochemical analyses. Poly I:C challenge had sex-dependent effects on general activity and mosquito defense behaviors. When compared to control females, Poly I:C challenged females hopped and fed less often in their general activities, but hopped more often in the presence of mosquitoes. Poly I:C challenged males did not differ from control males in any behaviors. Brain analysis revealed that the nucleus taeniae of the amygdala (TnA) of Poly I:C challenged males were smaller in volume yet had more neurons expressing immediate-early gene proteins compared with controls, suggesting a more active TnA. These results suggest that immune challenges early in the life could have long-term effects on behaviors and brains of zebra finches, which may influence disease spread and fitness of individual birds.
Collapse
|
45
|
|
46
|
Burgan SC, Gervasi SS, Martin LB. Parasite Tolerance and Host Competence in Avian Host Defense to West Nile Virus. ECOHEALTH 2018; 15:360-371. [PMID: 29569179 DOI: 10.1007/s10393-018-1332-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 02/15/2018] [Accepted: 03/07/2018] [Indexed: 06/08/2023]
Abstract
Competence, or the propensity of a host to transmit parasites, is partly underlain by host strategies to cope with infection (e.g., resistance and tolerance). Resistance represents the ability of hosts to prevent or clear infections, whereas tolerance captures the ability of individuals to cope with a given parasite burden. Here, we investigated (1) whether one easy-to-measure form of tolerance described well the dynamic relationships between host health and parasite burden, and (2) whether individual resistance and tolerance to West Nile virus (WNV) were predictable from single cytokine measures. We exposed house sparrows (HOSP) to WNV and measured subsequent changes in host performance, viral burden, and cytokine expression. We then used two novel approaches (one complex, one simpler) to estimate tolerance within-individual HOSP using four separate host performance traits. We lastly investigated changes in the expression of pro-inflammatory cytokine interferon-γ (IFN-γ) and anti-inflammatory cytokine interleukin-10 (IL-10). Both approaches to estimating tolerance were equivalent among WNV-infected HOSP; thus, an easy-to-measure tolerance estimation may be successfully applied in field studies. Constitutive expression of IFN-γ and IL-10 were predictive of resistance and tolerance to WNV, implicating these cytokines as viable biomarkers of host competence to WNV.
Collapse
Affiliation(s)
- Sarah C Burgan
- Department of Integrative Biology, University of South Florida, SCA 130, 12037 USF Beard Drive, Tampa, FL, 33620, USA
| | | | - Lynn B Martin
- Department of Integrative Biology, University of South Florida, SCA 130, 12037 USF Beard Drive, Tampa, FL, 33620, USA.
| |
Collapse
|
47
|
Vitousek MN, Johnson MA, Donald JW, Francis CD, Fuxjager MJ, Goymann W, Hau M, Husak JF, Kircher BK, Knapp R, Martin LB, Miller ET, Schoenle LA, Uehling JJ, Williams TD. HormoneBase, a population-level database of steroid hormone levels across vertebrates. Sci Data 2018; 5:180097. [PMID: 29786693 PMCID: PMC5963335 DOI: 10.1038/sdata.2018.97] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/29/2018] [Indexed: 12/30/2022] Open
Abstract
Hormones are central regulators of organismal function and flexibility that mediate a diversity of phenotypic traits from early development through senescence. Yet despite these important roles, basic questions about how and why hormone systems vary within and across species remain unanswered. Here we describe HormoneBase, a database of circulating steroid hormone levels and their variation across vertebrates. This database aims to provide all available data on the mean, variation, and range of plasma glucocorticoids (both baseline and stress-induced) and androgens in free-living and un-manipulated adult vertebrates. HormoneBase (www.HormoneBase.org) currently includes >6,580 entries from 476 species, reported in 648 publications from 1967 to 2015, and unpublished datasets. Entries are associated with data on the species and population, sex, year and month of study, geographic coordinates, life history stage, method and latency of hormone sampling, and analysis technique. This novel resource could be used for analyses of the function and evolution of hormone systems, and the relationships between hormonal variation and a variety of processes including phenotypic variation, fitness, and species distributions.
Collapse
Affiliation(s)
- Maren N Vitousek
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Michele A Johnson
- Department of Biology, Trinity University, San Antonio, TX 78212, USA
| | - Jeremy W Donald
- Coates Library, Trinity University, San Antonio, TX 78212, USA
| | - Clinton D Francis
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Matthew J Fuxjager
- Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA
| | | | - Michaela Hau
- Max Planck Institute for Ornithology, Seewiesen 82319, Germany
| | - Jerry F Husak
- Department of Biology, University of St. Thomas, St. Paul, MN 55105, USA
| | - Bonnie K Kircher
- Department of Biology, University of Florida, Gainesville, FL 32608, USA
| | - Rosemary Knapp
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Lynn B Martin
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | | | - Laura A Schoenle
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | - Jennifer J Uehling
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Tony D Williams
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| |
Collapse
|
48
|
Keiser CN, Rudolf VHW, Sartain E, Every ER, Saltz JB. Social context alters host behavior and infection risk. Behav Ecol 2018. [DOI: 10.1093/beheco/ary060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Carl N Keiser
- Rice University Academy of Fellows, Rice University, Houston, TX, USA
- Department of BioSciences, Rice University, Houston, TX, USA
| | | | | | - Emma R Every
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Julia B Saltz
- Department of BioSciences, Rice University, Houston, TX, USA
| |
Collapse
|
49
|
Kilvitis HJ, Hanson H, Schrey AW, Martin LB. Epigenetic Potential as a Mechanism of Phenotypic Plasticity in Vertebrate Range Expansions. Integr Comp Biol 2018; 57:385-395. [PMID: 28859411 DOI: 10.1093/icb/icx082] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
SYNOPSIS During range expansions, organisms are often exposed to multiple pressures, including novel enemies (i.e., predators, competitors and/or parasites) and unfamiliar or limited resources. Additionally, small propagule sizes at range edges can result in genetic founder effects and bottlenecks, which can affect phenotypic diversity and thus selection. Despite these obstacles, individuals in expanding populations often thrive at the periphery of a range, and this success may be mediated by phenotypic plasticity. Increasing evidence suggests that epigenetic mechanisms may underlie such plasticity because they allow for more rapid phenotypic responses to novel environments than are possible via the accumulation of genetic variation. Here, we review how molecular epigenetic mechanisms could facilitate plasticity in range-expanding organisms, emphasizing the roles of DNA methylation and other epigenetic marks in the physiological regulatory networks that drive whole-organism performance. We focus on the hypothalamic-pituitary-adrenal (HPA) axis, arguing that epigenetically-mediated plasticity in the regulation of glucocorticoids in particular might strongly impact range expansions. We hypothesize that novel environments release and/or select for epigenetic potential in HPA variation and hence organismal performance and ultimately fitness.
Collapse
Affiliation(s)
- Holly J Kilvitis
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Haley Hanson
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Aaron W Schrey
- Department of Biology, Armstrong State University, Savannah, GA 31419, USA
| | - Lynn B Martin
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| |
Collapse
|
50
|
Keiser CN, Pinter-Wollman N, Ziemba MJ, Kothamasu KS, Pruitt JN. The primary case is not enough: Variation among individuals, groups and social networks modify bacterial transmission dynamics. J Anim Ecol 2018; 87:369-378. [PMID: 28692130 PMCID: PMC5871623 DOI: 10.1111/1365-2656.12729] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 06/13/2017] [Indexed: 12/26/2022]
Abstract
The traits of the primary case of an infectious disease outbreak, and the circumstances for their aetiology, potentially influence the trajectory of transmission dynamics. However, these dynamics likely also depend on the traits of the individuals with whom the primary case interacts. We used the social spider Stegodyphus dumicola to test how the traits of the primary case, group phenotypic composition and group size interact to facilitate the transmission of a GFP-labelled cuticular bacterium. We also compared bacterial transmission across experimentally generated "daisy-chain" vs. "star" networks of social interactions. Finally, we compared social network structure across groups of different sizes. Groups of 10 spiders experienced more bacterial transmission events compared to groups of 30 spiders, regardless of groups' behavioural composition. Groups containing only one bold spider experienced the lowest levels of bacterial transmission regardless of group size. We found no evidence for the traits of the primary case influencing any transmission dynamics. In a second experiment, bacteria were transmitted to more individuals in experimentally induced star networks than in daisy-chains, on which transmission never exceeded three steps. In both experimental network types, transmission success depended jointly on the behavioural traits of the interacting individuals; however, the behavioural traits of the primary case were only important for transmission on star networks. Larger social groups exhibited lower interaction density (i.e. had a low ratio of observed to possible connections) and were more modular, i.e. they had more connections between nodes within a subgroup and fewer connections across subgroups. Thus, larger groups may restrict transmission by forming fewer interactions and by isolating subgroups that interacted with the primary case. These findings suggest that accounting for the traits of single exposed hosts has less power in predicting transmission dynamics compared to the larger scale factors of the social groups in which they reside. Factors like group size and phenotypic composition appear to alter social interaction patterns, which leads to differential transmission of microbes.
Collapse
Affiliation(s)
- Carl N. Keiser
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
- Biosciences Department, Rice University, Academy of Fellows, Rice University, Houston, TX, USA
| | - Noa Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | - Michael J. Ziemba
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Krishna S. Kothamasu
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jonathan N. Pruitt
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| |
Collapse
|