1
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Samaddar S, Rolandelli A, O'Neal AJ, Laukaitis-Yousey HJ, Marnin L, Singh N, Wang X, Butler LR, Rangghran P, Kitsou C, Cabrera Paz FE, Valencia L, R Ferraz C, Munderloh UG, Khoo B, Cull B, Rosche KL, Shaw DK, Oliver J, Narasimhan S, Fikrig E, Pal U, Fiskum GM, Polster BM, Pedra JHF. Bacterial reprogramming of tick metabolism impacts vector fitness and susceptibility to infection. Nat Microbiol 2024:10.1038/s41564-024-01756-0. [PMID: 38997520 DOI: 10.1038/s41564-024-01756-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/11/2024] [Indexed: 07/14/2024]
Abstract
Arthropod-borne pathogens are responsible for hundreds of millions of infections in humans each year. The blacklegged tick, Ixodes scapularis, is the predominant arthropod vector in the United States and is responsible for transmitting several human pathogens, including the Lyme disease spirochete Borrelia burgdorferi and the obligate intracellular rickettsial bacterium Anaplasma phagocytophilum, which causes human granulocytic anaplasmosis. However, tick metabolic response to microbes and whether metabolite allocation occurs upon infection remain unknown. Here we investigated metabolic reprogramming in the tick ectoparasite I. scapularis and determined that the rickettsial bacterium A. phagocytophilum and the spirochete B. burgdorferi induced glycolysis in tick cells. Surprisingly, the endosymbiont Rickettsia buchneri had a minimal effect on bioenergetics. An unbiased metabolomics approach following A. phagocytophilum infection of tick cells showed alterations in carbohydrate, lipid, nucleotide and protein metabolism, including elevated levels of the pleiotropic metabolite β-aminoisobutyric acid. We manipulated the expression of genes associated with β-aminoisobutyric acid metabolism in I. scapularis, resulting in feeding impairment, diminished survival and reduced bacterial acquisition post haematophagy. Collectively, we discovered that metabolic reprogramming affects interspecies relationships and fitness in the clinically relevant tick I. scapularis.
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Affiliation(s)
- Sourabh Samaddar
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Agustin Rolandelli
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Anya J O'Neal
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Hanna J Laukaitis-Yousey
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Liron Marnin
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Nisha Singh
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
- Department of Biotechnology, School of Energy Technology, Pandit Deendayal Energy University; Knowledge Corridor, Gandhinagar, India
| | - Xiaowei Wang
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
- MP Biomedicals, Solon, OH, USA
| | - L Rainer Butler
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Parisa Rangghran
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Chrysoula Kitsou
- Department of Veterinary Medicine, University of Maryland, College Park, MD, USA
| | - Francy E Cabrera Paz
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Luisa Valencia
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Camila R Ferraz
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA
| | | | - Benedict Khoo
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Benjamin Cull
- Department of Entomology, University of Minnesota, Saint Paul, MN, USA
| | - Kristin L Rosche
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, USA
| | - Dana K Shaw
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, USA
| | - Jonathan Oliver
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Sukanya Narasimhan
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT, USA
| | - Erol Fikrig
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT, USA
| | - Utpal Pal
- Department of Veterinary Medicine, University of Maryland, College Park, MD, USA
| | - Gary M Fiskum
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Brian M Polster
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Joao H F Pedra
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, USA.
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2
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Smith LA, Fox NJ, Marion G, Booth NJ, Morris AMM, Athanasiadou S, Hutchings MR. Animal Behaviour Packs a Punch: From Parasitism to Production, Pollution and Prevention in Grazing Livestock. Animals (Basel) 2024; 14:1876. [PMID: 38997988 PMCID: PMC11240309 DOI: 10.3390/ani14131876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/06/2024] [Accepted: 06/20/2024] [Indexed: 07/14/2024] Open
Abstract
Behaviour is often the fundamental driver of disease transmission, where behaviours of individuals can be seen to scale up to epidemiological patterns seen at the population level. Here we focus on animal behaviour, and its role in parasite transmission to track its knock-on consequences for parasitism, production and pollution. Livestock face a nutrition versus parasitism trade-off in grazing environments where faeces creates both a nutritional benefit, fertilizing the surrounding sward, but also a parasite risk from infective nematode larvae contaminating the sward. The grazing decisions of ruminants depend on the perceived costs and benefits of the trade-off, which depend on the variations in both environmental (e.g., amounts of faeces) and animal factors (e.g., physiological state). Such grazing decisions determine the intake of both nutrients and parasites, affecting livestock growth rates and production efficiency. This impacts on the greenhouse gas costs of ruminant livestock production via two main mechanisms: (1) slower growth results in longer durations on-farm and (2) parasitised animals produce more methane per unit food intake. However, the sensitivity of behaviour to host parasite state offers opportunities for early detection of parasitism and control. Remote monitoring technology such as accelerometers can detect parasite-induced sickness behaviours soon after exposure, before impacts on growth, and thus may be used for targeting individuals for early treatment. We conclude that livestock host x parasite interactions are at the centre of the global challenges of food security and climate change, and that understanding livestock behaviour can contribute to solving both.
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Affiliation(s)
- Lesley A Smith
- Animal and Veterinary Sciences, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
| | - Naomi J Fox
- Animal and Veterinary Sciences, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
| | - Glenn Marion
- Biomathematics and Statistics Scotland (BioSS), Kings Buildings, Edinburgh EH9 3FD, UK
| | - Naomi J Booth
- Animal and Veterinary Sciences, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
| | - Alex M M Morris
- Animal and Veterinary Sciences, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
| | - Spiridoula Athanasiadou
- Animal and Veterinary Sciences, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
| | - Michael R Hutchings
- Animal and Veterinary Sciences, Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK
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3
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Dziuba MK, McIntire KM, Seto K, Davenport ES, Rogalski MA, Gowler CD, Baird E, Vaandrager M, Huerta C, Jaye R, Corcoran FE, Withrow A, Ahrendt S, Salamov A, Nolan M, Tejomurthula S, Barry K, Grigoriev IV, James TY, Duffy MA. Phylogeny, morphology, virulence, ecology, and host range of Ordospora pajunii (Ordosporidae), a microsporidian symbiont of Daphnia spp. mBio 2024; 15:e0058224. [PMID: 38651867 PMCID: PMC11237803 DOI: 10.1128/mbio.00582-24] [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: 02/27/2024] [Accepted: 03/20/2024] [Indexed: 04/25/2024] Open
Abstract
The impacts of microsporidia on host individuals are frequently subtle and can be context dependent. A key example of the latter comes from a recently discovered microsporidian symbiont of Daphnia, the net impact of which was found to shift from negative to positive based on environmental context. Given this, we hypothesized low baseline virulence of the microsporidian; here, we investigated the impact of infection on hosts in controlled conditions and the absence of other stressors. We also investigated its phylogenetic position, ecology, and host range. The genetic data indicate that the symbiont is Ordospora pajunii, a newly described microsporidian parasite of Daphnia. We show that O. pajunii infection damages the gut, causing infected epithelial cells to lose microvilli and then rupture. The prevalence of this microsporidian could be high (up to 100% in the lab and 77% of adults in the field). Its overall virulence was low in most cases, but some genotypes suffered reduced survival and/or reproduction. Susceptibility and virulence were strongly host-genotype dependent. We found that North American O. pajunii were able to infect multiple Daphnia species, including the European species Daphnia longispina, as well as Ceriodaphnia spp. Given the low, often undetectable virulence of this microsporidian and potentially far-reaching consequences of infections for the host when interacting with other pathogens or food, this Daphnia-O. pajunii symbiosis emerges as a valuable system for studying the mechanisms of context-dependent shifts between mutualism and parasitism, as well as for understanding how symbionts might alter host interactions with resources. IMPORTANCE The net outcome of symbiosis depends on the costs and benefits to each partner. Those can be context dependent, driving the potential for an interaction to change between parasitism and mutualism. Understanding the baseline fitness impact in an interaction can help us understand those shifts; for an organism that is generally parasitic, it should be easier for it to become a mutualist if its baseline virulence is relatively low. Recently, a microsporidian was found to become beneficial to its Daphnia hosts in certain ecological contexts, but little was known about the symbiont (including its species identity). Here, we identify it as the microsporidium Ordospora pajunii. Despite the parasitic nature of microsporidia, we found O. pajunii to be, at most, mildly virulent; this helps explain why it can shift toward mutualism in certain ecological contexts and helps establish O. pajunii is a valuable model for investigating shifts along the mutualism-parasitism continuum.
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Affiliation(s)
- Marcin K. Dziuba
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kristina M. McIntire
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kensuke Seto
- Faculty of Environment and Information Sciences, Yokohama National University, Yokohama, Kanagawa, Japan
| | - Elizabeth S. Davenport
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mary A. Rogalski
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
- Biology Department, Bowdoin College, Brunswick, Maine, USA
| | - Camden D. Gowler
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Emma Baird
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Megan Vaandrager
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Cristian Huerta
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Riley Jaye
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Fiona E. Corcoran
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Alicia Withrow
- Center for Advanced Microscopy, Michigan State University, East Lansing, Michigan, USA
| | - Steven Ahrendt
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Asaf Salamov
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Matt Nolan
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Sravanthi Tejomurthula
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Kerrie Barry
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Igor V. Grigoriev
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Timothy Y. James
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Meghan A. Duffy
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
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Dean AD, Childs DZ, Corripio‐Miyar Y, Evans M, Hayward A, Kenyon F, McNally L, McNeilly TN, Pakeman RJ, Sweeny AR, Nussey DH, Pedersen AB, Fenton A. Host resources and parasite traits interact to determine the optimal combination of host parasite-mitigation strategies. Ecol Evol 2024; 14:e11310. [PMID: 38903143 PMCID: PMC11187858 DOI: 10.1002/ece3.11310] [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: 12/20/2023] [Revised: 03/29/2024] [Accepted: 04/03/2024] [Indexed: 06/22/2024] Open
Abstract
Organisms have evolved diverse strategies to manage parasite infections. Broadly, hosts may avoid infection by altering behaviour, resist infection by targeting parasites or tolerate infection by repairing associated damage. The effectiveness of a strategy depends on interactions between, for example, resource availability, parasite traits (virulence, life-history) and the host itself (nutritional status, immunopathology). To understand how these factors shape host parasite-mitigation strategies, we developed a mathematical model of within-host, parasite-immune dynamics in the context of helminth infections. The model incorporated host nutrition and resource allocation to different mechanisms of immune response: larval parasite prevention; adult parasite clearance; damage repair (tolerance). We also considered a non-immune strategy: avoidance via anorexia, reducing intake of infective stages. Resources not allocated to immune processes promoted host condition, whereas harm due to parasites and immunopathology diminished it. Maximising condition (a proxy for fitness), we determined optimal host investment for each parasite-mitigation strategy, singly and combined, across different environmental resource levels and parasite trait values. Which strategy was optimal varied with scenario. Tolerance generally performed well, especially with high resources. Success of the different resistance strategies (larval prevention or adult clearance) tracked relative virulence of larval and adult parasites: slowly maturing, highly damaging larvae favoured prevention; rapidly maturing, less harmful larvae favoured clearance. Anorexia was viable only in the short term, due to reduced host nutrition. Combined strategies always outperformed any lone strategy: these were dominated by tolerance, with some investment in resistance. Choice of parasite mitigation strategy has profound consequences for hosts, impacting their condition, survival and reproductive success. We show that the efficacy of different strategies is highly dependent on timescale, parasite traits and resource availability. Models that integrate such factors can inform the collection and interpretation of empirical data, to understand how those drivers interact to shape host immune responses in natural systems.
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Affiliation(s)
- Andrew D. Dean
- Institute of Infection, Veterinary and Ecological SciencesUniversity of LiverpoolLiverpoolUK
| | | | | | - Mike Evans
- Department for Disease ControlMoredun Research InstitutePenicuikUK
- The University of Edinburgh Royal (Dick) School of Veterinary StudiesRoslinUK
- Institute of Ecology and Evolution, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Adam Hayward
- Department for Disease ControlMoredun Research InstitutePenicuikUK
| | - Fiona Kenyon
- Department for Disease ControlMoredun Research InstitutePenicuikUK
| | - Luke McNally
- Institute of Ecology and Evolution, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Tom N. McNeilly
- Department for Disease ControlMoredun Research InstitutePenicuikUK
| | | | - Amy R. Sweeny
- School of BiosciencesThe University of SheffieldSheffieldUK
- Institute of Ecology and Evolution, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Daniel H. Nussey
- Institute of Ecology and Evolution, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Amy B. Pedersen
- Institute of Ecology and Evolution, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Andy Fenton
- Institute of Infection, Veterinary and Ecological SciencesUniversity of LiverpoolLiverpoolUK
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5
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Coblentz KE, Treidel LA, Biagioli FP, Fragel CG, Johnson AE, Thilakarathne DD, Yang L, DeLong JP. A framework for understanding climate change impacts through non-compensatory intra- and interspecific climate change responses. GLOBAL CHANGE BIOLOGY 2024; 30:e17378. [PMID: 38923246 DOI: 10.1111/gcb.17378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 05/16/2024] [Accepted: 05/25/2024] [Indexed: 06/28/2024]
Abstract
Understanding and predicting population responses to climate change is a crucial challenge. A key component of population responses to climate change are cases in which focal biological rates (e.g., population growth rates) change in response to climate change due to non-compensatory effects of changes in the underlying components (e.g., birth and death rates) determining the focal rates. We refer to these responses as non-compensatory climate change effects. As differential responses of biological rates to climate change have been documented in a variety of systems and arise at multiple levels of organization within and across species, non-compensatory effects may be nearly ubiquitous. Yet, how non-compensatory climate change responses combine and scale to influence the demographics of populations is often unclear and requires mapping them to the birth and death rates underlying population change. We provide a flexible framework for incorporating non-compensatory changes in upstream rates within and among species and mapping their consequences for additional downstream rates across scales to their eventual effects on population growth rates. Throughout, we provide specific examples and potential applications of the framework. We hope this framework helps to enhance our understanding of and unify research on population responses to climate change.
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Affiliation(s)
- Kyle E Coblentz
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Lisa A Treidel
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Francis P Biagioli
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Christina G Fragel
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Allison E Johnson
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | | | - Liuqingqing Yang
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - John P DeLong
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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Sankararaman S, Venegas C, Seth S, Palchaudhuri S. "Feed a Cold, Starve a Fever?" A Review of Nutritional Strategies in the Setting of Bacterial Versus Viral Infections. Curr Nutr Rep 2024; 13:314-322. [PMID: 38587572 DOI: 10.1007/s13668-024-00536-w] [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] [Accepted: 03/27/2024] [Indexed: 04/09/2024]
Abstract
PURPOSE OF REVIEW Some data, mostly originally derived from animal studies, suggest that low glucose intake is protective in bacterial sepsis but detrimental in overwhelming viral infections. This has been interpreted into a broad belief that different forms of sepsis may potentially require different nutritional management strategies. There are a few mechanistic differences between the host interactions with virus and bacteria which can explain why there may be opposing responses to macronutrient and micronutrient during the infected state. Here, we aim to review relevant evidence on the mechanisms and pathophysiology of nutritional management strategies in various infectious syndromes and summarize their clinical implications. RECENT FINDINGS Newer literature - in the context of the SARS-CoV-19 pandemic - offers some insight to viral infections. There is still limited clinically applicable data during infection that clearly delineate the role of nutrition during an active viral vs bacterial infections. Based on contrasting findings in different models of viruses and bacteria, the macronutrient and micronutrient needs may depend more on specific infectious organisms that may not be generalizable as bacterial versus viral. Overall, the metabolic effects of sepsis are context dependent, and various host-specific (e.g., age, baseline nutritional status, immune status, comorbidities) and illness variables (phase, duration, and severity of illness) play a significant role in determining the outcome besides pathogen-specific (virus or bacterial or fungi and combined infections) factors. Microbe therapy (probiotics and prebiotics) seems to have therapeutic potential in both viral and bacterial infected states, and this seems like a promising area for further practical research.
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Affiliation(s)
- Senthilkumar Sankararaman
- Division of Pediatric Gastroenterology, UH Rainbow Babies & Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Carla Venegas
- Department Critical Care Medicine and Nutrition Support Team, Mayo Clinic, Jacksonville, FL, USA
| | - Sonia Seth
- Upstate Medical University, Syracuse, NY, USA
| | - Sonali Palchaudhuri
- Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA.
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7
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Thieltges DW, Johnson PTJ, van Leeuwen A, Koprivnikar J. Effects of predation risk on parasite-host interactions and wildlife diseases. Ecology 2024; 105:e4315. [PMID: 38679953 PMCID: PMC11147705 DOI: 10.1002/ecy.4315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/20/2024] [Indexed: 05/01/2024]
Abstract
Landscapes of fear can determine the dynamics of entire ecosystems. In response to perceived predation risk, prey can show physiological, behavioral, or morphological trait changes to avoid predation. This in turn can indirectly affect other species by modifying species interactions (e.g., altered feeding), with knock-on effects, such as trophic cascades, on the wider ecosystem. While such indirect effects stemming from the fear of predation have received extensive attention for herbivore-plant and predator-prey interactions, much less is known about how they alter parasite-host interactions and wildlife diseases. In this synthesis, we present a conceptual framework for how predation risk-as perceived by organisms that serve as hosts-can affect parasite-host interactions, with implications for infectious disease dynamics. By basing our approach on recent conceptual advances with respect to predation risk effects, we aim to expand this general framework to include parasite-host interactions and diseases. We further identify pathways through which parasite-host interactions can be affected, for example, through altered parasite avoidance behavior or tolerance of hosts to infections, and discuss the wider relevance of predation risk for parasite and host populations, including heuristic projections to population-level dynamics. Finally, we highlight the current unknowns, specifically the quantitative links from individual-level processes to population dynamics and community structure, and emphasize approaches to address these knowledge gaps.
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Affiliation(s)
- David W Thieltges
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, The Netherlands
- Groningen Institute for Evolutionary Life-Sciences, GELIFES, University of Groningen, Groningen, The Netherlands
| | - Pieter T J Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, USA
| | - Anieke van Leeuwen
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, The Netherlands
| | - Janet Koprivnikar
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, Ontario, Canada
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8
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Penczykowski RM, Fearon ML, Hite JL, Shocket MS, Hall SR, Duffy MA. Pathways linking nutrient enrichment, habitat structure, and parasitism to host-resource interactions. Oecologia 2024; 204:439-449. [PMID: 37951848 DOI: 10.1007/s00442-023-05469-9] [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: 02/16/2023] [Accepted: 10/13/2023] [Indexed: 11/14/2023]
Abstract
Human activities simultaneously alter nutrient levels, habitat structure, and levels of parasitism. These activities likely have individual and joint impacts on food webs. Furthermore, there is particular concern that nutrient additions and changes to habitat structure might exacerbate the size of epidemics and impacts on host density. We used a well-studied zooplankton-fungus host-parasite system and experimental whole water column enclosures to factorially manipulate nutrient levels, habitat structure (specifically: mixing), and presence of parasites. Nutrient addition increased infection prevalence, density of infected hosts, and total host density. We hypothesized that nutrients, mixing, and parasitism were linked in multiple ways, including via their combined effects on phytoplankton (resource) abundance, and we used structural equation modeling to disentangle these pathways. In the absence of the parasite, both nutrients and mixing increased abundance of phytoplankton, whereas host density was negatively related to phytoplankton abundance, suggesting a mixture of bottom-up and top-down control of phytoplankton. In the presence of the parasite, nutrients still increased phytoplankton abundance but mixing no longer did, and there was no longer a significant relationship between host density and phytoplankton. This decoupling of host-resource dynamics may have resulted from reduced grazing due to illness-mediated changes in feeding behavior. Overall, our results show that the impact of one human activity (e.g., altered habitat structure) might depend on other human impacts (e.g., parasite introduction). Fortunately, carefully designed experiments and analyses can help tease apart these multifaceted relationships, allowing us to understand how human activities alter food webs, including interactions between hosts and their parasites and resources.
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Affiliation(s)
- Rachel M Penczykowski
- School of Biology, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Michelle L Fearon
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jessica L Hite
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Marta S Shocket
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
- Department of Geography, University of Florida, Gainesville, FL, 32611, USA
| | - Spencer R Hall
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Meghan A Duffy
- School of Biology, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
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9
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Hite JL, Roos AMD. Pathogens stabilize or destabilize depending on host stage structure. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2023; 20:20378-20404. [PMID: 38124557 DOI: 10.3934/mbe.2023901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
A common assumption is that pathogens more readily destabilize their host populations, leading to an elevated risk of driving both the host and pathogen to extinction. This logic underlies many strategies in conservation biology and pest and disease management. Yet, the interplay between pathogens and population stability likely varies across contexts, depending on the environment and traits of both the hosts and pathogens. This context-dependence may be particularly important in natural consumer-host populations where size- and stage-structured competition for resources strongly modulates population stability. Few studies, however, have examined how the interplay between size and stage structure and infectious disease shapes the stability of host populations. Here, we extend previously developed size-dependent theory for consumer-resource interactions to examine how pathogens influence the stability of host populations across a range of contexts. Specifically, we integrate a size- and stage-structured consumer-resource model and a standard epidemiological model of a directly transmitted pathogen. The model reveals surprisingly rich dynamics, including sustained oscillations, multiple steady states, biomass overcompensation, and hydra effects. Moreover, these results highlight how the stage structure and density of host populations interact to either enhance or constrain disease outbreaks. Our results suggest that accounting for these cross-scale and bidirectional feedbacks can provide key insight into the structuring role of pathogens in natural ecosystems while also improving our ability to understand how interventions targeting one may impact the other.
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Affiliation(s)
- Jessica L Hite
- University of Wisconsin-Madison, Department of Pathobiological Sciences, School of Veterinary Medicine, Madison, Wisconsin, USA
| | - André M de Roos
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands; Santa Fe Institute, Santa Fe, NM 87501, USA
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10
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Vicente-Santos A, Willink B, Nowak K, Civitello DJ, Gillespie TR. Host-pathogen interactions under pressure: A review and meta-analysis of stress-mediated effects on disease dynamics. Ecol Lett 2023; 26:2003-2020. [PMID: 37804128 PMCID: PMC10874615 DOI: 10.1111/ele.14319] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/07/2023] [Accepted: 09/12/2023] [Indexed: 10/08/2023]
Abstract
Human activities have increased the intensity and frequency of natural stressors and created novel stressors, altering host-pathogen interactions and changing the risk of emerging infectious diseases. Despite the ubiquity of such anthropogenic impacts, predicting the directionality of outcomes has proven challenging. Here, we conduct a review and meta-analysis to determine the primary mechanisms through which stressors affect host-pathogen interactions and to evaluate the impacts stress has on host fitness (survival and fecundity) and pathogen infectivity (prevalence and intensity). We assessed 891 effect sizes from 71 host species (representing seven taxonomic groups) and 78 parasite taxa from 98 studies. We found that infected and uninfected hosts had similar sensitivity to stressors and that responses varied according to stressor type. Specifically, limited resources compromised host fecundity and decreased pathogen intensity, while abiotic environmental stressors (e.g., temperature and salinity) decreased host survivorship and increased pathogen intensity, and pollution increased mortality but decreased pathogen prevalence. We then used our meta-analysis results to develop susceptible-infected theoretical models to illustrate scenarios where infection rates are expected to increase or decrease in response to resource limitations or environmental stress gradients. Our results carry implications for conservation and disease emergence and reveal areas for future work.
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Affiliation(s)
- Amanda Vicente-Santos
- Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA 30322, USA
| | - Beatriz Willink
- Department of Zoology, Stockholm University, Stockholm 106-91, Sweden
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
- School of Biology, University of Costa Rica, San José 11501-2060, Costa Rica
| | - Kacy Nowak
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - David J. Civitello
- Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA 30322, USA
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Thomas R. Gillespie
- Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA 30322, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
- Department of Environmental Sciences, Emory University, Atlanta, GA 30322, USA
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11
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Speakman JR, Hall KD. Models of body weight and fatness regulation. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220231. [PMID: 37661735 PMCID: PMC10475878 DOI: 10.1098/rstb.2022.0231] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/13/2023] [Indexed: 09/05/2023] Open
Abstract
Body weight and fatness appear to be regulated phenomena. Several different theoretical models are available to capture the essence of this idea. These include the set-point, dynamic equilibrium, adiposity force, control theory-settling point, Hall-Guo, operation point and dual intervention point (DIP) models. The set-point model posits a single reference point around which levels of fat are regulated. The dynamic equilibrium model suggests that the apparent regulation of body fat around a reference point is an illusion owing to the necessary impacts of weight change on energy expenditure. Control theory focuses on the importance of feedback gain and suggests set-point and dynamic equilibrium are ends of a continuum of feedback gain. Control theory models have also been called 'settling point' models. The Hall-Guo, operation point and DIP models also bring together the set-point and dynamic equilibrium ideas into a single framework. The DIP proposes a zone of indifference where dynamic equilibrium 'regulation' predominates, bounded by upper and lower intervention points beyond which physiological mechanisms are activated. The drifty gene hypothesis is an idea explaining where this individual variation in the upper intervention point might come from. We conclude that further experiments to test between the models are sorely required. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.
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Affiliation(s)
- John R. Speakman
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong Province, 518055, People's Republic of China
- School of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
- China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Kevin D. Hall
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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12
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Srygley RB. Selective protein self-deprivation by Mormon crickets following fungal attack. JOURNAL OF INSECT PHYSIOLOGY 2023; 149:104555. [PMID: 37595783 DOI: 10.1016/j.jinsphys.2023.104555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 08/20/2023]
Abstract
Immune responses to infection result in behavioral changes that affect resource acquisition, such as general starvation and compensatory feeding to offset changes in resource allocation. Mormon crickets aggregate and march in bands containing millions of insects. Some bands are comprised of insects seeking proteins. They are also low in circulating phenoloxidase (PO) and more susceptible to fungal attack, as we have demonstrated in the lab. Here, we ask: Do Mormon crickets elevate PO and consume protein in response to infection by the pathogenic fungus Beauveria bassiana? B. bassiana was applied topically (day 0), and mortality began on day 5. Total protein, PO, and prophenoloxidase (proPO) were assayed in hemolymph on day 1 and 4. On day 1, PO titers were not different between inoculated and control insects, whereas by day 4, PO was greater in the inoculated group. proPO activity was unchanged. Circulating protein declined in inoculated insects relative to controls. As predicted, PO titers were elevated as a result of fungal infection, and hemolymph protein was reduced, but the insects did not compensate behaviorally. Indeed, during the first three days post-infection, infected insects reduced protein consumption while maintaining carbohydrate consumption similar to the controls. Following day 3, a more general reduction in protein and carbohydrate intake was evident in infected insects. Survivorship to infection was associated with the amount of protein consumed and unrelated to carbohydrate consumption. Selective protein deprivation by the host seems counterintuitive, but it might limit growth and toxin production by the invading fungus. Alternatively, the fungus might control the host diet to compromise host immunity to infection. Abrupt changes in allocation resulting from an infection can lead to changes in acquisition that are not always intuitive. Because protein acquisition drives aggression between members of the migratory band, B. bassiana application may reduce cannibalism and slow band movement.
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Affiliation(s)
- Robert B Srygley
- USDA-Agricultural Research Service, Northern Plains Agricultural Research Laboratory, 1500 N. Central Ave., Sidney, MT 59270, USA.
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13
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Born-Torrijos A, Riekenberg P, van der Meer MTJ, Nachev M, Sures B, Thieltges DW. Parasite effects on host's trophic and isotopic niches. Trends Parasitol 2023; 39:749-759. [PMID: 37451950 DOI: 10.1016/j.pt.2023.06.003] [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: 03/08/2023] [Revised: 06/09/2023] [Accepted: 06/09/2023] [Indexed: 07/18/2023]
Abstract
Wild animals are usually infected with parasites that can alter their hosts' trophic niches in food webs as can be seen from stable isotope analyses of infected versus uninfected individuals. The mechanisms influencing these effects of parasites on host isotopic values are not fully understood. Here, we develop a conceptual model to describe how the alteration of the resource intake or the internal resource use of hosts by parasites can lead to differences of trophic and isotopic niches of infected versus uninfected individuals and ultimately alter resource flows through food webs. We therefore highlight that stable isotope studies inferring trophic positions of wild organisms in food webs would benefit from routine identification of their infection status.
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Affiliation(s)
- Ana Born-Torrijos
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands.
| | - Philip Riekenberg
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands
| | - Marcel T J van der Meer
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands
| | - Milen Nachev
- Department of Aquatic Ecology and Centre for Water and Environmental Research, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - Bernd Sures
- Department of Aquatic Ecology and Centre for Water and Environmental Research, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany; Research Center One Health Ruhr, Research Alliance Ruhr, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - David W Thieltges
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands; Groningen Institute for Evolutionary Life-Sciences, GELIFES, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
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14
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Jensen CH, Weidner J, Giske J, Jørgensen C, Eliassen S, Mennerat A. Adaptive host responses to infection can resemble parasitic manipulation. Ecol Evol 2023; 13:e10318. [PMID: 37456066 PMCID: PMC10349281 DOI: 10.1002/ece3.10318] [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: 03/22/2023] [Revised: 06/22/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023] Open
Abstract
Using a dynamic optimisation model for juvenile fish in stochastic food environments, we investigate optimal hormonal regulation, energy allocation and foraging behaviour of a growing host infected by a parasite that only incurs an energetic cost. We find it optimal for the infected host to have higher levels of orexin, growth and thyroid hormones, resulting in higher activity levels, increased foraging and faster growth. This growth strategy thus displays several of the fingerprints often associated with parasite manipulation: higher levels of metabolic hormones, faster growth, higher allocation to reserves (i.e. parasite-induced gigantism), higher risk-taking and eventually higher predation rate. However, there is no route for manipulation in our model, so these changes reflect adaptive host compensatory responses. Interestingly, several of these changes also increase the fitness of the parasite. Our results call for caution when interpreting observations of gigantism or risky host behaviours as parasite manipulation without further testing.
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Affiliation(s)
| | | | - Jarl Giske
- Department of Biological SciencesUniversity of BergenBergenNorway
| | | | - Sigrunn Eliassen
- Department of Biological SciencesUniversity of BergenBergenNorway
| | - Adèle Mennerat
- Department of Biological SciencesUniversity of BergenBergenNorway
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15
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Samaddar S, O’Neal AJ, Marnin L, Rolandelli A, Singh N, Wang X, Butler LR, Rangghran P, Laukaitis HJ, Cabrera Paz FE, Fiskum GM, Polster BM, Pedra JHF. Metabolic disruption impacts tick fitness and microbial relationships. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.26.542501. [PMID: 37292783 PMCID: PMC10245996 DOI: 10.1101/2023.05.26.542501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Arthropod-borne microbes rely on the metabolic state of a host to cycle between evolutionarily distant species. For instance, arthropod tolerance to infection may be due to redistribution of metabolic resources, often leading to microbial transmission to mammals. Conversely, metabolic alterations aids in pathogen elimination in humans, who do not ordinarily harbor arthropod-borne microbes. To ascertain the effect of metabolism on interspecies relationships, we engineered a system to evaluate glycolysis and oxidative phosphorylation in the tick Ixodes scapularis. Using a metabolic flux assay, we determined that the rickettsial bacterium Anaplasma phagocytophilum and the Lyme disease spirochete Borrelia burgdorferi, which are transstadially transmitted in nature, induced glycolysis in ticks. On the other hand, the endosymbiont Rickettsia buchneri, which is transovarially maintained, had a minimal effect on I. scapularis bioenergetics. Importantly, the metabolite β-aminoisobutyric acid (BAIBA) was elevated during A. phagocytophilum infection of tick cells following an unbiased metabolomics approach. Thus, we manipulated the expression of genes associated with the catabolism and anabolism of BAIBA in I. scapularis and detected impaired feeding on mammals, reduced bacterial acquisition, and decreased tick survival. Collectively, we reveal the importance of metabolism for tick-microbe relationships and unveil a valuable metabolite for I. scapularis fitness.
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Affiliation(s)
- Sourabh Samaddar
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Anya J. O’Neal
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Liron Marnin
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Agustin Rolandelli
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Nisha Singh
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Xiaowei Wang
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - L. Rainer Butler
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Parisa Rangghran
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Hanna J. Laukaitis
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Francy E. Cabrera Paz
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Gary M. Fiskum
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Brian M. Polster
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Joao H. F. Pedra
- Department of Microbiology and Immunology, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
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16
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Pfenning-Butterworth AC, Vetter RE, Hite JL. Natural variation in host feeding behaviors impacts host disease and pathogen transmission potential. Ecol Evol 2023; 13:e9865. [PMID: 36911315 PMCID: PMC9992943 DOI: 10.1002/ece3.9865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/09/2023] [Indexed: 03/10/2023] Open
Abstract
Animals ranging from mosquitoes to humans often vary their feeding behavior when infected or merely exposed to pathogens. These so-called "sickness behaviors" are part of the innate immune response with many consequences, including avoiding orally transmitted pathogens. Fully understanding the role of this ubiquitous behavior in host defense and pathogen evolution requires a quantitative account of its impact on host and pathogen fitness across environmentally relevant contexts. Here, we use a zooplankton host and fungal pathogen as a case study to ask if infection-mediated feeding behaviors vary across pathogen exposure levels and natural genetic variation in susceptibility to infection. Then, we connect these changes in behavior to pathogen transmission potential (spore yield) and fitness and growth costs to the host. Our results validate a protective effect of altered feeding behavior during pathogen exposure while also revealing significant variation in the magnitude of this response across host susceptibility and pathogen exposure levels. Across all four host genotypes, feeding rates were negatively correlated with susceptibility to infection and transmission potential. The most susceptible genotypes exhibited either strong anorexia, reducing food intake by 26%-42%, ("Standard") or pronounced hyperphagia, increasing food intake by 20%-54% ("A45"). Together, these results suggest that infection-mediated changes in host feeding behavior-which are traditionally interpreted as immunopathology- may in fact serve as crucial components of host defense strategies and warrant further investigation.
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Affiliation(s)
- Alaina C Pfenning-Butterworth
- School of Biological Sciences University of Nebraska Lincoln Nebraska USA.,Department of Botany University of British Columbia Vancouver British Columbia Canada
| | - Rachel E Vetter
- School of Biological Sciences University of Nebraska Lincoln Nebraska USA
| | - Jessica L Hite
- School of Biological Sciences University of Nebraska Lincoln Nebraska USA.,Department of Pathobiological Sciences University of Wisconsin Madison Wisconsin USA
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17
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Gsell AS, Biere A, de Boer W, de Bruijn I, Eichhorn G, Frenken T, Geisen S, van der Jeugd H, Mason-Jones K, Meisner A, Thakur MP, van Donk E, Zwart MP, Van de Waal DB. Environmental refuges from disease in host-parasite interactions under global change. Ecology 2023; 104:e4001. [PMID: 36799146 DOI: 10.1002/ecy.4001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/04/2022] [Accepted: 12/08/2022] [Indexed: 02/18/2023]
Abstract
The physiological performance of organisms depends on their environmental context, resulting in performance-response curves along environmental gradients. Parasite performance-response curves are generally expected to be broader than those of their hosts due to shorter generation times and hence faster adaptation. However, certain environmental conditions may limit parasite performance more than that of the host, thereby providing an environmental refuge from disease. Thermal disease refuges have been extensively studied in response to climate warming, but other environmental factors may also provide environmental disease refuges which, in turn, respond to global change. Here, we (1) showcase laboratory and natural examples of refuges from parasites along various environmental gradients, and (2) provide hypotheses on how global environmental change may affect these refuges. We strive to synthesize knowledge on potential environmental disease refuges along different environmental gradients including salinity and nutrients, in both natural and food-production systems. Although scaling up from single host-parasite relationships along one environmental gradient to their interaction outcome in the full complexity of natural environments remains difficult, integrating host and parasite performance-response can serve to formulate testable hypotheses about the variability in parasitism outcomes and the occurrence of environmental disease refuges under current and future environmental conditions.
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Affiliation(s)
- Alena S Gsell
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Ecosystem Research Department, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Arjen Biere
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Soil Biology Group, Wageningen University & Research, Wageningen, The Netherlands
| | - Irene de Bruijn
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Koppert, Berkel en Rodenrijs, The Netherlands
| | - Götz Eichhorn
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Centre for Avian Migration and Demography, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Thijs Frenken
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Great Lakes Institute for Environmental Research (GLIER), University of Windsor, Windsor, Ontario, Canada
| | - Stefan Geisen
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Department of Nematology, Wageningen University and Research, Wageningen, The Netherlands
| | - Henk van der Jeugd
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Centre for Avian Migration and Demography, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Kyle Mason-Jones
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Annelein Meisner
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Wageningen University & Research, Wageningen Research, Wageningen, The Netherlands.,Microbial Ecology Group, Department of Biology, Lund University, Lund, Sweden
| | - Madhav P Thakur
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Terrestrial Ecology Group, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Ellen van Donk
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Mark P Zwart
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Dedmer B Van de Waal
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
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18
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Hite JL, Pfenning-Butterworth A, Auld SKJR. Commentary: Infectious disease — the ecological theater and the evolutionary play. Evol Ecol 2023. [DOI: 10.1007/s10682-023-10229-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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19
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Molbert N, Goutte A. Narrower isotopic niche size in fish infected by the intestinal parasite Pomphorhynchus sp. compared to uninfected ones. JOURNAL OF FISH BIOLOGY 2022; 101:1466-1473. [PMID: 36097411 DOI: 10.1111/jfb.15217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 09/09/2022] [Indexed: 06/15/2023]
Abstract
Examples of parasite-related effects on intermediate crustacean hosts are numerous but their ecological consequences on their vertebrate hosts are scarce. Here, we address the role of macroparasite infections on the trophic niche structure of definitive hosts and its potential physiological consequences using wild fish populations infected with an acantochephalan parasite Pomphorhynchus sp., a trophically transmitted intestinal worm. Infected and uninfected fish were sampled from six populations on the Marne River, France and the prevalence of intestinal parasites in the host populations ranged from 50% to 90%. Although the isotopic ratios (δ13 C and δ15 N) did not differ between infected and uninfected fish, we found a consistent pattern of isotopic niche size being considerably smaller in infected hosts when compared with noninfected ones. This was not explained by interindividual differences in intrinsic factors such as length/age or body condition between infected and uninfected fish. These results suggest a potential niche specialization of infected fish, which did not impair their energetic status.
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Affiliation(s)
- Noëlie Molbert
- Centre National de la Recherche Scientifique (CNRS), EPHE, UMR METIS, Sorbonne Université, Paris, France
| | - Aurélie Goutte
- Centre National de la Recherche Scientifique (CNRS), EPHE, UMR METIS, Sorbonne Université, Paris, France
- École Pratique des Hautes Études, PSL Research University, Paris, France
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20
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Ranea-Robles P, Lund J, Clemmensen C. The physiology of experimental overfeeding in animals. Mol Metab 2022; 64:101573. [PMID: 35970448 PMCID: PMC9440064 DOI: 10.1016/j.molmet.2022.101573] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/04/2022] [Accepted: 08/07/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Body weight is defended by strong homeostatic forces. Several of the key biological mechanisms that counteract weight loss have been unraveled over the last decades. In contrast, the mechanisms that protect body weight and fat mass from becoming too high remain largely unknown. Understanding this aspect of energy balance regulation holds great promise for curbing the obesity epidemic. Decoding the physiological and molecular pathways that defend against weight gain can be achieved by an intervention referred to as 'experimental overfeeding'. SCOPE OF THE REVIEW In this review, we define experimental overfeeding and summarize the studies that have been conducted on animals. This field of research shows that experimental overfeeding induces a potent and prolonged hypophagic response that seems to be conserved across species and mediated by unidentified endocrine factors. In addition, the literature shows that experimental overfeeding can be used to model the development of non-alcoholic steatohepatitis and that forced intragastric infusion of surplus calories lowers survival from infections. Finally, we highlight studies indicating that experimental overfeeding can be employed to study the transgenerational effects of a positive energy balance and how dietary composition and macronutrient content might impact energy homeostasis and obesity development in animals. MAJOR CONCLUSIONS Experimental overfeeding of animals is a powerful yet underappreciated method to investigate the defense mechanisms against weight gain. This intervention also represents an alternative approach for studying the pathophysiology of metabolic liver diseases and the links between energy balance and infection biology. Future research in this field could help uncover why humans respond differently to an obesogenic environment and reveal novel pathways with therapeutic potential against obesity and cardiometabolic disorders.
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Affiliation(s)
- Pablo Ranea-Robles
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Jens Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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21
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Morris AM, Innocent GT, Cunningham EJ, Athanasiadou S, Hutchings MR, Smith LA. Early signals of parasitism expressed through behaviour but modulated by social context. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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22
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Stewart Merrill TE, Cáceres CE, Gray S, Laird VR, Schnitzler ZT, Buck JC. Timescale reverses the relationship between host density and infection risk. Proc Biol Sci 2022; 289:20221106. [PMID: 35919996 PMCID: PMC9346366 DOI: 10.1098/rspb.2022.1106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/08/2022] [Indexed: 12/14/2022] Open
Abstract
Host density shapes infection risk through two opposing phenomena. First, when infective stages are subdivided among multiple hosts, greater host densities decrease infection risk through 'safety in numbers'. Hosts, however, represent resources for parasites, and greater host availability also fuels parasite reproduction. Hence, host density increases infection risk through 'density-dependent transmission'. Theory proposes that these phenomena are not disparate outcomes but occur over different timescales. That is, higher host densities may reduce short-term infection risk, but because they support parasite reproduction, may increase long-term risk. We tested this theory in a zooplankton-disease system with laboratory experiments and field observations. Supporting theory, we found that negative density-risk relationships (safety in numbers) sometimes emerged over short timescales, but these relationships reversed to 'density-dependent transmission' within two generations. By allowing parasite numerical responses to play out, time can shift the consequences of host density, from reduced immediate risk to amplified future risk.
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Affiliation(s)
- Tara E. Stewart Merrill
- Coastal and Marine Laboratory, Florida State University, St. Teresa, FL 32358, USA
- Program in Ecology, Evolution and Conservation Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Carla E. Cáceres
- Program in Ecology, Evolution and Conservation Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- School of Integrative Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Samantha Gray
- School of Integrative Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Veronika R. Laird
- School of Integrative Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Department of Epidemiology, Emory University, Atlanta, GA 30322, USA
| | - Zoe T. Schnitzler
- Program in Ecology, Evolution and Conservation Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Julia C. Buck
- Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403, USA
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23
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Eads D, Livieri T, Tretten T, Hughes J, Kaczor N, Halsell E, Grassel S, Dobesh P, Childers E, Lucas D, Noble L, Vasquez M, Grady AC, Biggins D. Assembling a safe and effective toolbox for integrated flea control and plague mitigation: Fipronil experiments with prairie dogs. PLoS One 2022; 17:e0272419. [PMID: 35939486 PMCID: PMC9359584 DOI: 10.1371/journal.pone.0272419] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 07/19/2022] [Indexed: 11/19/2022] Open
Abstract
Background Plague, a widely distributed zoonotic disease of mammalian hosts and flea vectors, poses a significant risk to ecosystems throughout much of Earth. Conservation biologists use insecticides for flea control and plague mitigation. Here, we evaluate the use of an insecticide grain bait, laced with 0.005% fipronil (FIP) by weight, with black-tailed prairie dogs (BTPDs, Cynomys ludovicianus). We consider safety measures, flea control, BTPD body condition, BTPD survival, efficacy of plague mitigation, and the speed of FIP grain application vs. infusing BTPD burrows with insecticide dusts. We also explore conservation implications for endangered black-footed ferrets (Mustela nigripes), which are specialized predators of Cynomys. Principal findings During 5- and 10-day laboratory trials in Colorado, USA, 2016–2017, FIP grain had no detectable acute toxic effect on 20 BTPDs that readily consumed the grain. During field experiments in South Dakota, USA, 2016–2020, FIP grain suppressed fleas on BTPDs for at least 12 months and up to 24 months in many cases; short-term flea control on a few sites was poor for unknown reasons. In an area of South Dakota where plague circulation appeared low or absent, FIP grain had no detectable effect, positive or negative, on BTPD survival. Experimental results suggest FIP grain may have improved BTPD body condition (mass:foot) and reproduction (juveniles:adults). During a 2019 plague epizootic in Colorado, BTPDs on 238 ha habitat were protected by FIP grain, whereas BTPDs were nearly eliminated on non-treated habitat. Applications of FIP grain were 2–4 times faster than dusting BTPD burrows. Significance Deltamethrin dust is the most commonly used insecticide for plague mitigation on Cynomys colonies. Fleas on BTPD colonies exhibit the ability to evolve resistance to deltamethrin after repeated annual treatments. Thus, more tools are needed. Accumulating data show orally-delivered FIP is safe and usually effective for flea control with BTPDs, though potential acute toxic effects cannot be ruled out. With continued study and refinement, FIP might be used in rotation with, or even replace deltamethrin, and serve an important role in Cynomys and black-footed ferret conservation. More broadly, our stepwise approach to research on FIP may function as a template or guide for evaluations of insecticides in the context of wildlife conservation.
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Affiliation(s)
- David Eads
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States of America
- * E-mail:
| | - Travis Livieri
- Prairie Wildlife Research, Stevens Point, Wisconsin, United States of America
| | - Tyler Tretten
- U.S. Fish and Wildlife Service, National Black-Footed Ferret Conservation Center, Carr, Colorado, United States of America
| | - John Hughes
- U.S. Fish and Wildlife Service, National Black-Footed Ferret Conservation Center, Carr, Colorado, United States of America
| | - Nick Kaczor
- U.S. Fish and Wildlife Service, Colorado Front Range National Wildlife Refuge Complex, Arvada, Colorado, United States of America
| | - Emily Halsell
- U.S. Fish and Wildlife Service, Colorado Front Range National Wildlife Refuge Complex, Arvada, Colorado, United States of America
| | - Shaun Grassel
- Lower Brule Sioux Tribe, Lower Brule, South Dakota, United States of America
| | - Phillip Dobesh
- U.S. Forest Service, Wall Ranger District, Wall, South Dakota, United States of America
| | - Eddie Childers
- National Park Service, Badlands National Park, Rapid City, South Dakota, United States of America
| | - David Lucas
- U.S. Fish and Wildlife Service, Colorado Front Range National Wildlife Refuge Complex, Arvada, Colorado, United States of America
| | - Lauren Noble
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States of America
| | - Michele Vasquez
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States of America
| | - Anna Catherine Grady
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States of America
| | - Dean Biggins
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States of America
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24
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Koltz AM, Civitello DJ, Becker DJ, Deem SL, Classen AT, Barton B, Brenn-White M, Johnson ZE, Kutz S, Malishev M, Preston DL, Vannatta JT, Penczykowski RM, Ezenwa VO. Sublethal effects of parasitism on ruminants can have cascading consequences for ecosystems. Proc Natl Acad Sci U S A 2022; 119:e2117381119. [PMID: 35533278 PMCID: PMC9171767 DOI: 10.1073/pnas.2117381119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 03/17/2022] [Indexed: 12/29/2022] Open
Abstract
Parasitic infections are common, but how they shape ecosystem-level processes is understudied. Using a mathematical model and meta-analysis, we explored the potential for helminth parasites to trigger trophic cascades through lethal and sublethal effects imposed on herbivorous ruminant hosts after infection. First, using the model, we linked negative effects of parasitic infection on host survival, fecundity, and feeding rate to host and producer biomass. Our model, parameterized with data from a well-documented producer–caribou–helminth system, reveals that even moderate impacts of parasites on host survival, fecundity, or feeding rate can have cascading effects on ruminant host and producer biomass. Second, using meta-analysis, we investigated the links between helminth infections and traits of free-living ruminant hosts in nature. We found that helminth infections tend to exert negative but sublethal effects on ruminant hosts. Specifically, infection significantly reduces host feeding rates, body mass, and body condition but has weak and highly variable effects on survival and fecundity. Together, these findings suggest that while helminth parasites can trigger trophic cascades through multiple mechanisms, overlooked sublethal effects on nonreproductive traits likely dominate their impacts on ecosystems. In particular, by reducing ruminant herbivory, pervasive helminth infections may contribute to a greener world.
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Affiliation(s)
- Amanda M. Koltz
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130
| | | | | | - Sharon L. Deem
- Saint Louis Zoo Institute for Conservation Medicine, Saint Louis, MO 63110
| | - Aimée T. Classen
- Ecology and Evolutionary Biology Department, University of Michigan, Ann Arbor, MI 48109
| | - Brandon Barton
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Maris Brenn-White
- Saint Louis Zoo Institute for Conservation Medicine, Saint Louis, MO 63110
| | - Zoë E. Johnson
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762
| | - Susan Kutz
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | | | - Daniel L. Preston
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO 80523
| | - J. Trevor Vannatta
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
| | | | - Vanessa O. Ezenwa
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511
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25
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Walsman JC, Strauss AT, Hall SR. Parasite‐driven cascades or hydra effects: Susceptibility and foraging depression shape parasite–host–resource interactions. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Penczykowski RM, Shocket MS, Ochs JH, Lemanski BCP, Sundar H, Duffy MA, Hall SR. Virulent Disease Epidemics Can Increase Host Density by Depressing Foraging of Hosts. Am Nat 2022; 199:75-90. [DOI: 10.1086/717175] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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27
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Cassidy ST, Chapa J, Tran TA, Dolezal N, Gerena C, Johnson G, Leyva A, Stein S, Wright CM, Keiser CN. Disease defences across levels of biological organization: individual and social immunity in acorn ants. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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28
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Strauss AT, Bowerman L, Porath‐Krause A, Seabloom EW, Borer ET. Mixed infection, risk projection, and misdirection: Interactions among pathogens alter links between host resources and disease. Ecol Evol 2021; 11:9599-9609. [PMID: 34306646 PMCID: PMC8293790 DOI: 10.1002/ece3.7781] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/18/2021] [Indexed: 11/27/2022] Open
Abstract
A growing body of literature links resources of hosts to their risk of infectious disease. Yet most hosts encounter multiple pathogens, and projections of disease risk based on resource availability could be fundamentally wrong if they do not account for interactions among pathogens within hosts. Here, we measured infection risk of grass hosts (Avena sativa) exposed to three naturally co-occurring viruses either singly or jointly (barley and cereal yellow dwarf viruses [B/CYDVs]: CYDV-RPV, BYDV-PAV, and BYDV-SGV) along experimental gradients of nitrogen and phosphorus supply. We asked whether disease risk (i.e., infection prevalence) differed in single versus co-inoculations, and whether these differences varied with rates and ratios of nitrogen and phosphorus supply. In single inoculations, the viruses did not respond strongly to nitrogen or phosphorus. However, in co-inoculations, we detected illustrative cases of 1) resource-dependent antagonism (lower prevalence of RPV with increasing N; possibly due to competition), 2) resource-dependent facilitation (higher prevalence of SGV with decreasing N:P; possibly due to immunosuppression), and 3) weak or no interactions within hosts (for PAV). Together, these within-host interactions created emergent patterns for co-inoculated hosts, with both infection prevalence and viral richness increasing with the combination of low nitrogen and high phosphorus supply. We demonstrate that knowledge of multiple pathogens is essential for predicting disease risk from host resources and that projections of risk that fail to acknowledge resource-dependent interactions within hosts could be qualitatively wrong. Expansions of theory from community ecology theory may help anticipate such relationships by linking host resources to diverse pathogen communities.
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Affiliation(s)
- Alexander T. Strauss
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMNUSA
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
| | - Lucas Bowerman
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMNUSA
| | - Anita Porath‐Krause
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMNUSA
| | - Eric W. Seabloom
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMNUSA
| | - Elizabeth T. Borer
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMNUSA
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29
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Bell O, Jones ME, Cunningham CX, Ruiz‐Aravena M, Hamilton DG, Comte S, Hamede RK, Bearhop S, McDonald RA. Isotopic niche variation in Tasmanian devils Sarcophilus harrisii with progression of devil facial tumor disease. Ecol Evol 2021; 11:8038-8053. [PMID: 34188870 PMCID: PMC8216929 DOI: 10.1002/ece3.7636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 04/12/2021] [Accepted: 04/15/2021] [Indexed: 12/11/2022] Open
Abstract
Devil facial tumor disease (DFTD) is a transmissible cancer affecting Tasmanian devils Sarcophilus harrisii. The disease has caused severe population declines and is associated with demographic and behavioral changes, including earlier breeding, younger age structures, and reduced dispersal and social interactions. Devils are generally solitary, but social encounters are commonplace when feeding upon large carcasses. DFTD tumors can disfigure the jaw and mouth and so diseased individuals might alter their diets to enable ingestion of alternative foods, to avoid conspecific interactions, or to reduce competition. Using stable isotope analysis (δ13C and δ15N) of whiskers, we tested whether DFTD progression, measured as tumor volume, affected the isotope ratios and isotopic niches of 94 infected Tasmanian devils from six sites in Tasmania, comprising four eucalypt plantations, an area of smallholdings and a national park. Then, using tissue from 10 devils sampled before and after detection of tumors and 8 devils where no tumors were detected, we examined whether mean and standard deviation of δ13C and δ15N of the same individuals changed between healthy and diseased states. δ13C and δ15N values were generally not related to tumor volume in infected devils, though at one site, Freycinet National Park, δ15N values increased significantly as tumor volume increased. Infection with DFTD was not associated with significant changes in the mean or standard deviation of δ13C and δ15N values in individual devils sampled before and after detection of tumors. Our analysis suggests that devils tend to maintain their isotopic niche in the face of DFTD infection and progression, except where ecological conditions facilitate a shift in diets and feeding behaviors, demonstrating that ecological context, alongside disease severity, can modulate the behavioral responses of Tasmanian devils to DFTD.
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Affiliation(s)
- Olivia Bell
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
| | - Menna E. Jones
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | | | - Manuel Ruiz‐Aravena
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
- Department of Microbiology and ImmunologyMontana State UniversityBozemanMTUSA
| | - David G. Hamilton
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Sebastien Comte
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
- Vertebrate Pest Research UnitNSW Department of Primary IndustriesOrangeNSWAustralia
| | - Rodrigo K. Hamede
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Stuart Bearhop
- Centre for Ecology and ConservationUniversity of ExeterPenrynUK
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30
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Tao Y, Hite JL, Lafferty KD, Earn DJD, Bharti N. Transient disease dynamics across ecological scales. THEOR ECOL-NETH 2021; 14:625-640. [PMID: 34075317 PMCID: PMC8156581 DOI: 10.1007/s12080-021-00514-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 05/04/2021] [Indexed: 11/25/2022]
Abstract
Analyses of transient dynamics are critical to understanding infectious disease transmission and persistence. Identifying and predicting transients across scales, from within-host to community-level patterns, plays an important role in combating ongoing epidemics and mitigating the risk of future outbreaks. Moreover, greater emphases on non-asymptotic processes will enable timely evaluations of wildlife and human diseases and lead to improved surveillance efforts, preventive responses, and intervention strategies. Here, we explore the contributions of transient analyses in recent models spanning the fields of epidemiology, movement ecology, and parasitology. In addition to their roles in predicting epidemic patterns and endemic outbreaks, we explore transients in the contexts of pathogen transmission, resistance, and avoidance at various scales of the ecological hierarchy. Examples illustrate how (i) transient movement dynamics at the individual host level can modify opportunities for transmission events over time; (ii) within-host energetic processes often lead to transient dynamics in immunity, pathogen load, and transmission potential; (iii) transient connectivity between discrete populations in response to environmental factors and outbreak dynamics can affect disease spread across spatial networks; and (iv) increasing species richness in a community can provide transient protection to individuals against infection. Ultimately, we suggest that transient analyses offer deeper insights and raise new, interdisciplinary questions for disease research, consequently broadening the applications of dynamical models for outbreak preparedness and management. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12080-021-00514-w.
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Affiliation(s)
- Yun Tao
- Intelligence Community Postdoctoral Research Fellowship Program, Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106 USA
| | - Jessica L. Hite
- School of Veterinary Medicine, Department of Pathobiological Sciences, University of Wisconsin, Madison, WI 53706 USA
| | - Kevin D. Lafferty
- Western Ecological Research Center at UCSB Marine Science Institute, U.S. Geological Survey, CA 93106 Santa Barbara, USA
| | - David J. D. Earn
- Department of Mathematics and Statistics, McMaster University, Hamilton, ON L8S 4K1 Canada
| | - Nita Bharti
- Department of Biology Center for Infectious Disease Dynamics, Penn State University, University Park, PA 16802 USA
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31
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Ellner SP, Buchon N, Dörr T, Lazzaro BP. Host-pathogen immune feedbacks can explain widely divergent outcomes from similar infections. Proc Biol Sci 2021; 288:20210786. [PMID: 34034518 DOI: 10.1098/rspb.2021.0786] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A long-standing question in infection biology is why two very similar individuals, with very similar pathogen exposures, may have very different outcomes. Recent experiments have found that even isogenic Drosophila melanogaster hosts, given identical inoculations of some bacterial pathogens at suitable doses, can experience very similar initial bacteria proliferation but then diverge to either a lethal infection or a sustained chronic infection with much lower pathogen load. We hypothesized that divergent infection outcomes are a natural result of mutual negative feedbacks between pathogens and the host immune response. Here, we test this hypothesis in silico by constructing process-based dynamic models for bacterial population growth, host immune induction and the feedbacks between them, based on common mechanisms of immune system response. Mathematical analysis of a minimal conceptual model confirms our qualitative hypothesis that mutual negative feedbacks can magnify small differences among hosts into life-or-death differences in outcome. However, explaining observed features of chronic infections requires an extension of the model to include induced pathogen modifications that shield themselves from host immune responses at the cost of reduced proliferation rate. Our analysis thus generates new, testable predictions about the mechanisms underlying bimodal infection outcomes.
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Affiliation(s)
- Stephen P Ellner
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.,Cornell Institute for Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY 14853, USA
| | - Nicolas Buchon
- Department of Entomology, Cornell University, Ithaca, NY 14853, USA.,Cornell Institute for Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY 14853, USA
| | - Tobias Dörr
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.,Cornell Institute for Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY 14853, USA.,Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Brian P Lazzaro
- Department of Entomology, Cornell University, Ithaca, NY 14853, USA.,Cornell Institute for Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY 14853, USA
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32
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Wale N, Duffy MA. The Use and Underuse of Model Systems in Infectious Disease Ecology and Evolutionary Biology. Am Nat 2021; 198:69-92. [PMID: 34143716 DOI: 10.1086/714595] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractEver since biologists began studying the ecology and evolution of infectious diseases (EEID), laboratory-based model systems have been important for developing and testing theory. Yet what EEID researchers mean by the term "model systems" and what they want from them is unclear. This uncertainty hinders our ability to maximally exploit these systems, identify knowledge gaps, and establish effective new model systems. Here, we borrow a definition of model systems from the biomolecular sciences to assess how EEID researchers are (and are not) using 10 key model systems. According to this definition, model systems in EEID are not being used to their fullest and, in fact, cannot even be considered model systems. Research using these systems consistently addresses only two of the three fundamental processes that underlie disease dynamics-transmission and disease, but not recovery. Furthermore, studies tend to focus on only a few scales of biological organization that matter for disease ecology and evolution. Moreover, the field lacks an infrastructure to perform comparative analyses. We aim to begin a discussion of what we want from model systems, which would further progress toward a thorough, holistic understanding of EEID.
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33
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Nørgaard LS, Ghedini G, Phillips BL, Hall MD. Energetic scaling across different host densities and its consequences for pathogen proliferation. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13721] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Louise Solveig Nørgaard
- School of Biological Sciences and Centre for Geometric Biology Monash University Melbourne Vic. Australia
| | - Giulia Ghedini
- School of Biological Sciences and Centre for Geometric Biology Monash University Melbourne Vic. Australia
| | - Ben L. Phillips
- Department of Biosciences University of Melbourne Parkville Vic. Australia
| | - Matthew D. Hall
- School of Biological Sciences and Centre for Geometric Biology Monash University Melbourne Vic. Australia
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34
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Tragust S, Herrmann C, Häfner J, Braasch R, Tilgen C, Hoock M, Milidakis MA, Gross R, Feldhaar H. Formicine ants swallow their highly acidic poison for gut microbial selection and control. eLife 2020; 9:e60287. [PMID: 33138912 PMCID: PMC7609056 DOI: 10.7554/elife.60287] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/14/2020] [Indexed: 12/23/2022] Open
Abstract
Animals continuously encounter microorganisms that are essential for health or cause disease. They are thus challenged to control harmful microbes while allowing the acquisition of beneficial microbes. This challenge is likely especially important for social insects with respect to microbes in food, as they often store food and exchange food among colony members. Here we show that formicine ants actively swallow their antimicrobial, highly acidic poison gland secretion. The ensuing acidic environment in the stomach, the crop, can limit the establishment of pathogenic and opportunistic microbes ingested with food and improve the survival of ants when faced with pathogen contaminated food. At the same time, crop acidity selectively allows acquisition and colonization by Acetobacteraceae, known bacterial gut associates of formicine ants. This suggests that swallowing of the poison in formicine ants acts as a microbial filter and that antimicrobials have a potentially widespread but so far underappreciated dual role in host-microbe interactions.
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Affiliation(s)
- Simon Tragust
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
| | - Claudia Herrmann
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
| | - Jane Häfner
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
| | - Ronja Braasch
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
| | - Christina Tilgen
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
| | - Maria Hoock
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
| | - Margarita Artemis Milidakis
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
| | - Roy Gross
- Microbiology, Biocenter, University of Würzburg, Am HublandWürzburgGermany
| | - Heike Feldhaar
- Animal Ecology I, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, UniversitätsstraßeBayreuthGermany
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35
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Roberts KE, Meaden S, Sharpe S, Kay S, Doyle T, Wilson D, Bartlett LJ, Paterson S, Boots M. Resource quality determines the evolution of resistance and its genetic basis. Mol Ecol 2020; 29:4128-4142. [PMID: 32860314 DOI: 10.1111/mec.15621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 10/23/2022]
Abstract
Parasites impose strong selection on their hosts, but the level of any evolved resistance may be constrained by the availability of resources. However, studies identifying the genomic basis of such resource-mediated selection are rare, particularly in nonmodel organisms. Here, we investigated the role of nutrition in the evolution of resistance to a DNA virus (PiGV), and any associated trade-offs in a lepidopteran pest species (Plodia interpunctella). Through selection experiments and whole-genome resequencing, we identify genetic markers of resistance that vary between the nutritional environments during selection. We do not find consistent evolution of resistance in the presence of virus but rather see substantial variation among replicate populations. Resistance in a low-nutrition environment is negatively correlated with growth rate, consistent with an established trade-off between immunity and development, but this relationship is highly context dependent. Whole-genome resequencing of the host shows that resistance mechanisms are likely to be highly polygenic and although the underlying genetic architecture may differ between high and low-nutrition environments, similar mechanisms are commonly used. As a whole, our results emphasize the importance of the resource environment on influencing the evolution of resistance.
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Affiliation(s)
- Katherine E Roberts
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Sean Meaden
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Stephen Sharpe
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Suzanne Kay
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Toby Doyle
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Drew Wilson
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | | | - Steve Paterson
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Mike Boots
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK.,Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
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36
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Genetic Underpinnings of Host Manipulation by Ophiocordyceps as Revealed by Comparative Transcriptomics. G3-GENES GENOMES GENETICS 2020; 10:2275-2296. [PMID: 32354705 PMCID: PMC7341126 DOI: 10.1534/g3.120.401290] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ant-infecting Ophiocordyceps fungi are globally distributed, host manipulating, specialist parasites that drive aberrant behaviors in infected ants, at a lethal cost to the host. An apparent increase in activity and wandering behaviors precedes a final summiting and biting behavior onto vegetation, which positions the manipulated ant in a site beneficial for fungal growth and transmission. We investigated the genetic underpinnings of host manipulation by: (i) producing a high-quality hybrid assembly and annotation of the Ophiocordyceps camponoti-floridani genome, (ii) conducting laboratory infections coupled with RNAseq of O. camponoti-floridani and its host, Camponotus floridanus, and (iii) comparing these data to RNAseq data of Ophiocordyceps kimflemingiae and Camponotus castaneus as a powerful method to identify gene expression patterns that suggest shared behavioral manipulation mechanisms across Ophiocordyceps-ant species interactions. We propose differentially expressed genes tied to ant neurobiology, odor response, circadian rhythms, and foraging behavior may result by activity of putative fungal effectors such as enterotoxins, aflatrem, and mechanisms disrupting feeding behaviors in the ant.
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Hite JL, Pfenning‐Butterworth AC, Vetter RE, Cressler CE. A high-throughput method to quantify feeding rates in aquatic organisms: A case study with Daphnia. Ecol Evol 2020; 10:6239-6245. [PMID: 32724510 PMCID: PMC7381556 DOI: 10.1002/ece3.6352] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 11/17/2022] Open
Abstract
Food ingestion is one of the most basic features of all organisms. However, obtaining precise-and high-throughput-estimates of feeding rates remains challenging, particularly for small, aquatic herbivores such as zooplankton, snails, and tadpoles. These animals typically consume low volumes of food that are time-consuming to accurately measure.We extend a standard high-throughput fluorometry technique, which uses a microplate reader and 96-well plates, as a practical tool for studies in ecology, evolution, and disease biology. We outline technical and methodological details to optimize quantification of individual feeding rates, improve accuracy, and minimize sampling error.This high-throughput assay offers several advantages over previous methods, including i) substantially reduced time allotments per sample to facilitate larger, more efficient experiments; ii) technical replicates; and iii) conversion of in vivo measurements to units (mL-1 hr-1 ind-1) which enables broad-scale comparisons across an array of taxa and studies.To evaluate the accuracy and feasibility of our approach, we use the zooplankton, Daphnia dentifera, as a case study. Our results indicate that this procedure accurately quantifies feeding rates and highlights differences among seven genotypes.The method detailed here has broad applicability to a diverse array of aquatic taxa, their resources, environmental contaminants (e.g., plastics), and infectious agents. We discuss simple extensions to quantify epidemiologically relevant traits, such as pathogen exposure and transmission rates, for infectious agents with oral or trophic transmission.
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Affiliation(s)
- Jessica L. Hite
- School of Biological SciencesUniversity of NebraskaLincolnNebraskaUSA
| | | | - Rachel E. Vetter
- School of Biological SciencesUniversity of NebraskaLincolnNebraskaUSA
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Strauss AT, Hite JL, Civitello DJ, Shocket MS, Cáceres CE, Hall SR. Genotypic variation in parasite avoidance behaviour and other mechanistic, nonlinear components of transmission. Proc Biol Sci 2019; 286:20192164. [PMID: 31744438 DOI: 10.1098/rspb.2019.2164] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Traditional epidemiological models assume that transmission increases proportionally to the density of parasites. However, empirical data frequently contradict this assumption. General yet mechanistic models can explain why transmission depends nonlinearly on parasite density and thereby identify potential defensive strategies of hosts. For example, hosts could decrease their exposure rates at higher parasite densities (via behavioural avoidance) or decrease their per-parasite susceptibility when encountering more parasites (e.g. via stronger immune responses). To illustrate, we fitted mechanistic transmission models to 19 genotypes of Daphnia dentifera hosts over gradients of the trophically acquired parasite, Metschnikowia bicuspidata. Exposure rate (foraging, F) frequently decreased with parasite density (Z), and per-parasite susceptibility (U) frequently decreased with parasite encounters (F × Z). Consequently, infection rates (F × U × Z) often peaked at intermediate parasite densities. Moreover, host genotypes varied substantially in these responses. Exposure rates remained constant for some genotypes but decreased sensitively with parasite density for others (up to 78%). Furthermore, genotypes with more sensitive foraging/exposure also foraged faster in the absence of parasites (suggesting 'fast and sensitive' versus 'slow and steady' strategies). These relationships suggest that high densities of parasites can inhibit transmission by decreasing exposure rates and/or per-parasite susceptibility, and identify several intriguing axes for the evolution of host defence.
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Affiliation(s)
| | - Jessica L Hite
- Department of Biology, Indiana University, Bloomington, IN 47401, USA
| | | | - Marta S Shocket
- Department of Biology, Indiana University, Bloomington, IN 47401, USA
| | - Carla E Cáceres
- School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Spencer R Hall
- Department of Biology, Indiana University, Bloomington, IN 47401, USA
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