1
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Raven N, Klaassen M, Madsen T, Jones M, Hamilton DG, Ruiz-Aravena M, Thomas F, Hamede RK, Ujvari B. Complex associations between cancer progression and immune gene expression reveals early influence of transmissible cancer on Tasmanian devils. Front Immunol 2024; 15:1286352. [PMID: 38515744 PMCID: PMC10954821 DOI: 10.3389/fimmu.2024.1286352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 01/29/2024] [Indexed: 03/23/2024] Open
Abstract
The world's largest extant carnivorous marsupial, the Tasmanian devil, is challenged by Devil Facial Tumor Disease (DFTD), a fatal, clonally transmitted cancer. In two decades, DFTD has spread across 95% of the species distributional range. A previous study has shown that factors such as season, geographic location, and infection with DFTD can impact the expression of immune genes in Tasmanian devils. To date, no study has investigated within-individual immune gene expression changes prior to and throughout the course of DFTD infection. To explore possible changes in immune response, we investigated four locations across Tasmania that differed in DFTD exposure history, ranging between 2 and >30 years. Our study demonstrated considerable complexity in the immune responses to DFTD. The same factors (sex, age, season, location and DFTD infection) affected immune gene expression both across and within devils, although seasonal and location specific variations were diminished in DFTD affected devils. We also found that expression of both adaptive and innate immune genes starts to alter early in DFTD infection and continues to change as DFTD progresses. A novel finding was that the lower expression of immune genes MHC-II, NKG2D and CD8 may predict susceptibility to earlier DFTD infection. A case study of a single devil with regressed tumor showed opposite/contrasting immune gene expression patterns compared to the general trends observed across devils with DFTD infection. Our study highlights the complexity of DFTD's interactions with the host immune system and the need for long-term studies to fully understand how DFTD alters the evolutionary trajectory of devil immunity.
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Affiliation(s)
- Nynke Raven
- Deakin University, School of Life and Environmental Sciences, Centre for Integrative Ecology, Geelong, VIC, Australia
| | - Marcel Klaassen
- Deakin University, School of Life and Environmental Sciences, Centre for Integrative Ecology, Geelong, VIC, Australia
| | - Thomas Madsen
- Deakin University, School of Life and Environmental Sciences, Centre for Integrative Ecology, Geelong, VIC, Australia
| | - Menna Jones
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - David G. Hamilton
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Manuel Ruiz-Aravena
- Mississippi State University, Forest & Wildlife Research Center (FWRC)-Wildlife, Fisheries & Aquaculture, Starkville, MS, United States
| | - Frederic Thomas
- CREEC/CANECEV, CREES-MIVEGEC, Univ. Montpellier, CNRS, IRD, Montpellier, France
| | - Rodrigo K. Hamede
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Beata Ujvari
- Deakin University, School of Life and Environmental Sciences, Centre for Integrative Ecology, Geelong, VIC, Australia
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2
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Johnson PTJ, Merrill TS, Calhoun DM, McDevitt-Galles T, Hobart B. Into the danger zone: How the within-host distribution of parasites controls virulence. Ecol Lett 2024; 27:e14352. [PMID: 38115188 PMCID: PMC10872350 DOI: 10.1111/ele.14352] [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: 02/20/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 12/21/2023]
Abstract
Despite the importance of virulence in epidemiological theory, the relative contributions of host and parasite to virulence outcomes remain poorly understood. Here, we use reciprocal cross experiments to disentangle the influence of host and parasite on core virulence components-infection and pathology-and understand dramatic differences in parasite-induced malformations in California amphibians. Surveys across 319 populations revealed that amphibians' malformation risk was 2.7× greater in low-elevation ponds, even while controlling for trematode infection load. Factorial experiments revealed that parasites from low-elevation sites induced higher per-parasite pathology (reduced host survival and growth), whereas there were no effects of host source on resistance or tolerance. Parasite populations also exhibited marked differences in within-host distribution: ~90% of low-elevation cysts aggregated around the hind limbs, relative to <60% from high-elevation. This offers a novel, mechanistic basis for regional variation in parasite-induced malformations while promoting a framework for partitioning host and parasite contributions to virulence.
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Affiliation(s)
| | - Tara Stewart Merrill
- Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
- Coastal and Marine Laboratory, Florida State University, St. Teresa, FL, 32358, USA
| | - Dana M. Calhoun
- Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Travis McDevitt-Galles
- Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
- Current address: USGS National Wildlife Health Center, Madison, WI, USA
| | - Brendan Hobart
- Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
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3
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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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4
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Experimental evidence of parasite-induced behavioural alterations modulated by food availability in wild capuchin monkeys. Sci Rep 2023; 13:3083. [PMID: 36813841 PMCID: PMC9947137 DOI: 10.1038/s41598-023-30262-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 02/20/2023] [Indexed: 02/24/2023] Open
Abstract
In disease dynamics, host behaviour can both determine the quantity of parasites a host is exposed to, and be a consequence of infection. Observational and experimental studies in non-human primates have consistently found that parasitic infections result in less movement and reduced foraging, which was interpreted as an adaptive response of the host to counter infection. Variation in host nutritional condition may add complexity to the infection-behaviour relationship, and its influence may shed light on its significance. To experimentally evaluate how host activity and social relationships are affected by the interaction of parasitism and nutrition, during two years we manipulated food availability by provisioning bananas, and helminth infections by applying antiparasitic drugs, in two groups of wild black capuchin monkeys (Sapajus nigritus) in Iguazú National Park, Argentina. We collected faecal samples to determine the intensity of helminthic infections, as well as data on behaviour and social proximity. Individuals with unmanipulated helminth burdens foraged less than dewormed individuals only when food provisioning was low. Resting time was increased when capuchins were highly provisioned, but it did not vary according to the antiparasitic treatment. Proximity associations to other group members were not affected by the antiparasitic treatment. This is the first experimental evidence of a modulating effect of food availability on the influence of helminth infection on activity in wild primates. The findings are more consistent with an impact on host behaviour due to the debilitating effect caused by parasites than with an adaptive response to help fight infections.
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5
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Strasburg M, Boone MD. Can predators stabilize host–parasite interactions? Changes in aquatic predator identity alter amphibian responses and parasite abundance across life stages. Ecol Evol 2022; 12:e9512. [PMID: 36407903 PMCID: PMC9666717 DOI: 10.1002/ece3.9512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/06/2022] [Accepted: 10/23/2022] [Indexed: 11/18/2022] Open
Abstract
The role of parasites can change depending on the food web community. Predators, for instance, can amplify or dilute parasite effects on their hosts. Likewise, exposure to parasites or predators at one life stage can have long‐term consequences on individual performance and survival, which can influence population and disease dynamics. To understand how predators affect amphibian parasite infections across life stages, we manipulated exposure of northern leopard frog (Rana pipiens) tadpoles to three predators (crayfish [Orconectes rusticus], bluegill [Lepomis macrochirus], or mosquitofish [Gambusia affinis]) and to trematode parasites (Echinostoma spp.) in mesocosms and followed juveniles in outdoor terrestrial enclosures through overwintering. Parasites and predators both had strong impacts on metamorphosis with bluegill and parasites individually reducing metamorph survival. However, when fish were present, the negative effects of parasites on survival was not apparent, likely because fish altered community composition via increased algal food resources. Bluegill also reduced snail abundance, which could explain reduced abundance of parasites in surviving metamorphs. Bluegill and parasite exposure increased mass at metamorphosis, which increased metamorph jumping, swimming, and feeding performance, suggesting that larger frogs would experience better terrestrial survival. Effects on size at metamorphosis persisted in the terrestrial environment but did not influence overwintering survival. Based on our results, we constructed stage‐structured population models to evaluate the lethal and sublethal effects of bluegill and parasites on population dynamics. Our models suggested that positive effects of bluegill and parasites on body size may have greater effects on population growth than the direct effects of mortality. This study illustrates how predators can alter the outcome of parasitic infections and highlights the need for long‐term experiments that investigate how changes in host–parasite systems alter population dynamics. We show that some predators reduce parasite effects and have indirect positive effects on surviving individuals potentially increasing host population persistence.
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6
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Divergence in host–parasite interactions during the cane toad's invasion of Australia. Ecol Evol 2022. [DOI: 10.1002/ece3.9220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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7
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Shu Y, Xie Y, Li S, Cai L, Liu Y, Feng Y, He J, Zhang H, Ran M, Jia Q, Wu H, Lu L. Risk and protection strategies of Amolops wuyiensis intestine against gastrointestinal nematode (Cosmocercoides wuyiensis n. sp.) infection. Environ Microbiol 2021; 24:1454-1466. [PMID: 34967095 DOI: 10.1111/1462-2920.15881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 12/18/2021] [Indexed: 12/13/2022]
Abstract
Anuran amphibians are susceptible to infection by intestinal nematodes, but the damage and response mechanisms that occur in their intestines after infection are only partially understood. In this study, the intestinal disruption and response mechanisms in Amolops wuyiensis frogs infected with Cosmocercoides wuyiensis n. sp. were revealed through analysis of the intestinal histopathology, digestive enzyme activity, transcriptome and intestinal microbiota. Tissue section analysis showed histological damage and inflammation in the infected intestine, and the digestive enzyme activity indicated a decrease in digestion and absorption of some nutrients. We found that infection led to differences in the intestinal microbiota composition, including lower diversity and symbiotic relationships. The greater relative abundance of the genera Burkholderia and Rhodococcus may enhance intestinal immunity to resist pathogenic infections. A comparison of the transcriptomes of infected and uninfected intestines revealed 1055 differentially expressed genes. GO enrichment and KEGG pathways analyses suggested that the guts of infected C. wuyiensis n. sp. show enhanced complement activation, cell adhesion molecule function, NOD-like receptor signalling pathway activity and other innate immunity responses. Among the adaptive immune responses, the intestinal immune network for IgA production was significantly enriched, and the expression of IL-17D and transforming growth factor beta-1 genes were upregulated in the infected intestine. These results imply that C. wuyiensis n. sp. infection of A. wuyiensis intestine may trigger innate and adaptive immune responses, which reduce the post-infection burden. Furthermore, the intestine of A. wuyiensis may also respond to C. wuyiensis n. sp. infection by increasing metallocarboxypeptidase activity and accelerating smooth muscle contraction.
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Affiliation(s)
- Yilin Shu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Yunyun Xie
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Shikun Li
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Liming Cai
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Ying Liu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China.,School of Basic Medicine, Wannan Medical College, Wuhu, Anhui, 241000, China
| | - Yalin Feng
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Jun He
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Huijuan Zhang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Menglong Ran
- Department of Dermatology and Venereology, Peking University First Hospital, Beijing, 100034, China
| | - Qina Jia
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Hailong Wu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.,Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, Wuhu, Anhui, 241002, China
| | - Linming Lu
- Department of Pathology, Wannan Medical College, Wuhu, Anhui, 241002, China
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8
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Ortega N, Roznik EA, Surbaugh KL, Cano N, Price W, Campbell T, Rohr JR. Parasite spillover to native hosts from more tolerant, supershedding invasive hosts: Implications for management. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nicole Ortega
- Department of Biology University of Tampa Tampa FL USA
| | - Elizabeth A. Roznik
- North Carolina Zoo Asheboro NC USA
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Kerri L. Surbaugh
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Natalia Cano
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Wayne Price
- Department of Biology University of Tampa Tampa FL USA
| | - Todd Campbell
- Department of Biology University of Tampa Tampa FL USA
| | - Jason R. Rohr
- Department of Biological Sciences University of Notre DameNotre Dame IN USA
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9
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Early-life exposure to Ivermectin alters long-term growth and disease susceptibility. PLoS One 2021; 16:e0258185. [PMID: 34644335 PMCID: PMC8513825 DOI: 10.1371/journal.pone.0258185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 09/21/2021] [Indexed: 11/19/2022] Open
Abstract
Ivermectin is a broad-spectrum antiparasitic medicine, which is often used as a treatment for parasites or as a prophylaxis. While studies have looked at the long-term effects of Ivermectin on helminths, studies have not considered the long-term impacts of this treatment on host health or disease susceptibility. Here, we tracked the effects of early life Ivermectin treatment in Cuban tree frogs (Osteopilus septentrionalis) on growth rates, mortality, metabolically expensive organ size, and susceptibility to Batrachochytrium dendrobatidis (Bd) infection. One year after exposure, there was no effect of Ivermectin exposure on frog mass (X21 = 0.904, p = 0.34), but when tracked through the exponential growth phase (~2.5 years) the Ivermectin exposed individuals had lower growth rates and were ultimately smaller (X21 = 7.78, p = 0.005; X21 = 5.36, p = 0.02, respectively). These results indicate that early life exposure is likely to have unintended impacts on organismal growth and potentially reproductive fitness. Additionally, we exposed frogs to Bd, a pathogenic fungus that has decimated amphibian populations globally, and found early life exposure to Ivermectin decreased disease susceptibility (disease load: X21 = 17.57, p = 0.0002) and prevalence (control: 55%; Ivermectin: 22%) over 2 years after exposure. More research is needed to understand the underlying mechanism behind this phenomenon. Given that Ivermectin exposure altered disease susceptibility, proper controls should be implemented when utilizing this drug as an antiparasitic treatment in research studies.
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10
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Seal S, Dharmarajan G, Khan I. Evolution of pathogen tolerance and emerging infections: A missing experimental paradigm. eLife 2021; 10:e68874. [PMID: 34544548 PMCID: PMC8455132 DOI: 10.7554/elife.68874] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/23/2021] [Indexed: 12/11/2022] Open
Abstract
Researchers worldwide are repeatedly warning us against future zoonotic diseases resulting from humankind's insurgence into natural ecosystems. The same zoonotic pathogens that cause severe infections in a human host frequently fail to produce any disease outcome in their natural hosts. What precise features of the immune system enable natural reservoirs to carry these pathogens so efficiently? To understand these effects, we highlight the importance of tracing the evolutionary basis of pathogen tolerance in reservoir hosts, while drawing implications from their diverse physiological and life-history traits, and ecological contexts of host-pathogen interactions. Long-term co-evolution might allow reservoir hosts to modulate immunity and evolve tolerance to zoonotic pathogens, increasing their circulation and infectious period. Such processes can also create a genetically diverse pathogen pool by allowing more mutations and genetic exchanges between circulating strains, thereby harboring rare alive-on-arrival variants with extended infectivity to new hosts (i.e., spillover). Finally, we end by underscoring the indispensability of a large multidisciplinary empirical framework to explore the proposed link between evolved tolerance, pathogen prevalence, and spillover in the wild.
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Affiliation(s)
| | - Guha Dharmarajan
- Savannah River Ecology Laboratory, University of GeorgiaAikenUnited States
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11
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Jithila PJ, Devi ARS, Prasadan PK, Abaunza P. Tetracotyle wayanadensis (Trematoda: Digenea) metacercaria - A potential parasitic castrator of the freshwater fish Aplocheilus lineatus (Valenciennes, 1846): A histopathological and temporal variation study in the South Western Ghats, India. Parasitol Int 2021; 84:102408. [PMID: 34175473 DOI: 10.1016/j.parint.2021.102408] [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: 12/15/2020] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
Parasitic castration is a phenomenon where the parasite blocks or reduces the host reproductive output. This study explored the impact of Tetracotyle wayanadensis infection on the reproductive performance of the freshwater fish Aplocheilus lineatus. Heavily infected A. lineatus showed slow and sluggish movements with reduced food intake and feeding activities. Histopathological observations of the ovary revealed severe necrosis and degeneration of previtellogenic and vitellogenic oocytes and follicular atresia. The oogonial nests were absent; chromatin nucleolar oocytes irregularly shaped and vacuolated. Perinucleolar oocytes have a vacuolated appearance with the hypertrophied highly columnar follicular cells invading them. Vitellogenic oocytes had a shrunken appearance with folded zona radiata; yolk globules broken down into smaller granules together with vacuolar degeneration of the ooplasm. The hypertrophied highly columnar follicular cells invaded the early vitellogenic oocytes to phagocytize the degenerating material. Zona radiata was found broken and liquefaction of yolk globules was evident with advancement in follicular atresia. Seasonal variation of parasitic infection has also been studied. Metacercaria infecting the vital organs showed seasonal variation with the highest values for prevalence and abundance during monsoon and mean intensity during winter. The lowest values for these descriptors were documented during the post-monsoon period.
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Affiliation(s)
- P J Jithila
- Ecological Parasitology and Tropical Biodiversity Laboratory, Department of Zoology, Kannur University, Mananthavady Campus, Wayanad 670645, Kerala, India
| | - A R Sudha Devi
- Ecological Parasitology and Tropical Biodiversity Laboratory, Department of Zoology, Kannur University, Mananthavady Campus, Wayanad 670645, Kerala, India
| | - P K Prasadan
- Ecological Parasitology and Tropical Biodiversity Laboratory, Department of Zoology, Kannur University, Mananthavady Campus, Wayanad 670645, Kerala, India.
| | - P Abaunza
- Instituto Español de Oceanografía (IEO), C.O. de Santander, Promontorio San Martín s/n 39004, Santander, Cantabria, Spain
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12
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Turner WC, Kamath PL, van Heerden H, Huang YH, Barandongo ZR, Bruce SA, Kausrud K. The roles of environmental variation and parasite survival in virulence-transmission relationships. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210088. [PMID: 34109041 PMCID: PMC8170194 DOI: 10.1098/rsos.210088] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Disease outbreaks are a consequence of interactions among the three components of a host-parasite system: the infectious agent, the host and the environment. While virulence and transmission are widely investigated, most studies of parasite life-history trade-offs are conducted with theoretical models or tractable experimental systems where transmission is standardized and the environment controlled. Yet, biotic and abiotic environmental factors can strongly affect disease dynamics, and ultimately, host-parasite coevolution. Here, we review research on how environmental context alters virulence-transmission relationships, focusing on the off-host portion of the parasite life cycle, and how variation in parasite survival affects the evolution of virulence and transmission. We review three inter-related 'approaches' that have dominated the study of the evolution of virulence and transmission for different host-parasite systems: (i) evolutionary trade-off theory, (ii) parasite local adaptation and (iii) parasite phylodynamics. These approaches consider the role of the environment in virulence and transmission evolution from different angles, which entail different advantages and potential biases. We suggest improvements to how to investigate virulence-transmission relationships, through conceptual and methodological developments and taking environmental context into consideration. By combining developments in life-history evolution, phylogenetics, adaptive dynamics and comparative genomics, we can improve our understanding of virulence-transmission relationships across a diversity of host-parasite systems that have eluded experimental study of parasite life history.
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Affiliation(s)
- Wendy C. Turner
- US Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Pauline L. Kamath
- School of Food and Agriculture, University of Maine, Orono, ME 04469, USA
| | - Henriette van Heerden
- Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
| | - Yen-Hua Huang
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Zoe R. Barandongo
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Spencer A. Bruce
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Kyrre Kausrud
- Section for Epidemiology, Norwegian Veterinary Institute, Ullevålsveien 68, 0454 Oslo, Norway
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13
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Bourgoin G, Portanier E, Poirel MT, Itty C, Duhayer J, Benabed S, Cockenpot A, Callait-Cardinal MP, Garel M. Reproductive females and young mouflon ( Ovis gmelini musimon × Ovis sp.) in poor body condition are the main spreaders of gastrointestinal parasites. Parasitology 2021; 148:809-818. [PMID: 33593470 PMCID: PMC11010168 DOI: 10.1017/s0031182021000329] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 11/07/2022]
Abstract
Several individual, environmental and parasitic factors can influence the impacts of parasites on host's fitness and on host's ability to transmit these parasites to new hosts. Identifying these factors and the individuals who play a greater role in parasite transmission is of main concern for the development of parasite control strategies. In the present study, we aimed to describe the diversity of gastrointestinal parasites and to identify the individual factors influencing the faecal spreading of parasites in a free-ranging population of Mediterranean mouflon. From the analysis of 433 faecal samples, we found Eimeria spp. and gastrointestinal strongyles (GIS) were the most common parasites (>94%). The faecal oocyst counts of Eimeria spp. were the highest during the first years of life. It was 1.6 times higher in females than in males and 2.5 times higher in individuals in poor than in good body condition. Similarly, the faecal egg count of GIS was higher in females and decreased with age, but only in males. Finally, reproductive females had GIS faecal egg count values 2.6 times higher than non-reproductive females. Management strategies of parasites should thus primarily focus on reproductive females and young individuals in poor body condition as they represent the main contamination source of the environment.
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Affiliation(s)
- Gilles Bourgoin
- Laboratoire de parasitologie vétérinaire, Université de Lyon, VetAgro Sup – Campus Vétérinaire de Lyon, 1 avenue Bourgelat, BP 83, F-69280 Marcy l'Etoile, France
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622Villeurbanne, France
| | - Elodie Portanier
- Laboratoire de parasitologie vétérinaire, Université de Lyon, VetAgro Sup – Campus Vétérinaire de Lyon, 1 avenue Bourgelat, BP 83, F-69280 Marcy l'Etoile, France
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622Villeurbanne, France
| | - Marie-Thérèse Poirel
- Laboratoire de parasitologie vétérinaire, Université de Lyon, VetAgro Sup – Campus Vétérinaire de Lyon, 1 avenue Bourgelat, BP 83, F-69280 Marcy l'Etoile, France
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622Villeurbanne, France
| | - Christian Itty
- Office Français de la Biodiversité, Unité Ongulés Sauvages, 5 allée de Bethléem, Z.I. Mayencin, F-38610Gières, France
| | - Jeanne Duhayer
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622Villeurbanne, France
| | - Slimania Benabed
- Laboratoire de parasitologie vétérinaire, Université de Lyon, VetAgro Sup – Campus Vétérinaire de Lyon, 1 avenue Bourgelat, BP 83, F-69280 Marcy l'Etoile, France
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622Villeurbanne, France
| | - Anne Cockenpot
- Laboratoire de parasitologie vétérinaire, Université de Lyon, VetAgro Sup – Campus Vétérinaire de Lyon, 1 avenue Bourgelat, BP 83, F-69280 Marcy l'Etoile, France
| | - Marie-Pierre Callait-Cardinal
- Laboratoire de parasitologie vétérinaire, Université de Lyon, VetAgro Sup – Campus Vétérinaire de Lyon, 1 avenue Bourgelat, BP 83, F-69280 Marcy l'Etoile, France
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622Villeurbanne, France
| | - Mathieu Garel
- Office Français de la Biodiversité, Unité Ongulés Sauvages, 5 allée de Bethléem, Z.I. Mayencin, F-38610Gières, France
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14
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Kim D, Shaw AK. Migration and tolerance shape host behaviour and response to parasite infection. J Anim Ecol 2021; 90:2315-2324. [PMID: 34014562 DOI: 10.1111/1365-2656.13539] [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: 03/22/2021] [Accepted: 05/03/2021] [Indexed: 11/26/2022]
Abstract
Numerous theoretical models have demonstrated that migration, a seasonal animal movement behaviour, can minimize the risks and costs of parasite infection. Past work on migration-infection interactions assumes migration is the only strategy available to organisms for dealing with the parasite infection, that is they migrate to a different environment to recover or escape from infection. Thus, migration is similar to the non-spatial strategy of resistance, where hosts prevent infection or kill parasites once infected. However, an alternative defence strategy is to tolerate the infection and experience a lower cost to the infection. To our knowledge, no studies have examined how migration can change based on combining two host strategies (migration and tolerance) for dealing with parasites. In this paper, we aim to understand how both parasite transmission and infection tolerance can influence the host's migratory behaviour. We constructed a model that incorporates two host strategies (migration and tolerance) to understand whether allowing for tolerance affects the proportion of the population that migrates at equilibrium in response to infection. We show that the benefits of tolerance can either decrease or increase the host's migration. Also, if the benefit of migration is great, then individuals are more likely to migrate regardless of the presence of tolerance. Finally, we find that the transmission rate of parasite infection can either decrease or increase the tolerant host's migration, depending on the cost of migration. These findings highlight that adopting two defence strategies is not always beneficial to the hosts. Instead, a single strategy is often better, depending on the costs and benefits of the strategies and infection pressures. Our work further suggests that multiple host-defence strategies as a potential explanation for the evolution of migration to minimize the parasite infection. Moreover, migration can also affect the ecological and evolutionary dynamics of parasite-host interactions.
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Affiliation(s)
- Dongmin Kim
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA
| | - Allison K Shaw
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA
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15
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Roberts KE, Longdon B. Viral susceptibility across host species is largely independent of dietary protein to carbohydrate ratios. J Evol Biol 2021; 34:746-756. [PMID: 33586293 PMCID: PMC8436156 DOI: 10.1111/jeb.13773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/02/2021] [Accepted: 02/07/2021] [Indexed: 12/23/2022]
Abstract
The likelihood of a successful host shift of a parasite to a novel host species can be influenced by environmental factors that can act on both the host and parasite. Changes in nutritional resource availability have been shown to alter pathogen susceptibility and the outcome of infection in a range of systems. Here, we examined how dietary protein to carbohydrate altered susceptibility in a large cross-infection experiment. We infected 27 species of Drosophilidae with an RNA virus on three food types of differing protein to carbohydrate ratios. We then measured how viral load and mortality across species was affected by changes in diet. We found that changes in the protein:carbohydrate in the diet did not alter the outcomes of infection, with strong positive inter-species correlations in both viral load and mortality across diets, suggesting no species-by-diet interaction. Mortality and viral load were strongly positively correlated, and this association was consistent across diets. This suggests changes in diet may give consistent outcomes across host species, and may not be universally important in determining host susceptibility to pathogens.
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Affiliation(s)
- Katherine E. Roberts
- Centre for Ecology & ConservationCollege of Life and Environmental SciencesUniversity of ExeterPenrynUK
| | - Ben Longdon
- Centre for Ecology & ConservationCollege of Life and Environmental SciencesUniversity of ExeterPenrynUK
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16
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Brown CR, Hannebaum SL, O’Brien VA, Page CE, Rannala B, Roche EA, Wagnon GS, Knutie SA, Moore AT, Brown MB. The cost of ectoparasitism in Cliff Swallows declines over 35 years. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1446] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Charles R. Brown
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
| | - Stacey L. Hannebaum
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
| | - Valerie A. O’Brien
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
| | - Catherine E. Page
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
| | - Bruce Rannala
- Department of Evolution and Ecology University of California Davis California 95616 USA
| | - Erin A. Roche
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
| | - Gigi S. Wagnon
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
| | - Sarah A. Knutie
- Department of Ecology and Evolutionary Biology University of Connecticut 75 N. Eagleville Rd. Storrs Connecticut 06269 USA
| | - Amy T. Moore
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
| | - Mary B. Brown
- Department of Biological Sciences University of Tulsa 800 S. Tucker Dr. Tulsa Oklahoma 74104 USA
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17
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Mayer M, Shine R, Brown GP. Rapid divergence of parasite infectivity and host resistance during a biological invasion. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blaa229] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Abstract
By perturbing co-evolved interactions, biological invasions provide an opportunity to study the evolution of interactions between hosts and their parasites on ecological timescales. We studied the interaction between the cane toad (Rhinella marina) and its direct-lifecycle lungworm (Rhabdias pseudosphaerocephala) that was brought from South America to Australia with the toads in 1935. Compared with infective parasite larvae from long-established (range-core) toad populations, parasite larvae from toads near the invasion front were larger, lived longer and were better able to resist exposure to toxin from the parotoid glands of toads. Experimentally, we infected the common-garden-reared progeny of toads from range-core and invasion-front populations within Australia with lungworms from both populations. Infective larvae from invasion-front (vs. range-core) populations of the parasite were more successful at entering toads (by skin penetration) and establishing infections in the lungs. Toads from invasion-front populations were less prone to infection by either type of larvae. Thus, within 84 years, parasites at an invasion front have increased infectivity, whereas hosts have increased resistance to parasite infection compared with range-core populations. Rapid evolution of traits might affect host–parasite interactions during biological invasions, generating unpredictable effects both on the invaders and on native ecosystems.
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Affiliation(s)
- Martin Mayer
- Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Richard Shine
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Gregory P Brown
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
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18
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Ramsay C, Rohr JR. The application of community ecology theory to co-infections in wildlife hosts. Ecology 2021; 102:e03253. [PMID: 33222193 DOI: 10.1002/ecy.3253] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/27/2020] [Accepted: 09/18/2020] [Indexed: 11/11/2022]
Abstract
Priority effect theory, a foundational concept from community ecology, states that the order and timing of species arrival during species assembly can affect species composition. Although this theory has been applied to co-infecting parasite species, it has almost always been with a single time lag between co-infecting parasites. Thus, how the timing of parasite species arrival affects co-infections and disease remains poorly understood. To address this gap in the literature, we exposed postmetamorphic Cuban tree frogs (Osteopilus septentrionalis) to Ranavirus, the fungus Batrachochytrium dendrobatidis (Bd), a nematode Aplectana hamatospicula, or pairs of these parasites either simultaneously or sequentially at a range of time lags and quantified load of the secondary parasite and host growth, survival, and parasite tolerance. Prior exposure to Bd or A. hamatospicula significantly increased viral loads relative to hosts singly infected with Ranavirus, whereas A. hamatospicula loads in hosts were higher when coexposed to Bd than when coexposed to Ranavirus. There was a significant positive relationship between time since Ranavirus infection and Bd load, and prior exposure to A. hamatospicula decreased Bd loads compared to simultaneous co-infection with these parasites. Infections with Bd and Ranavirus either singly or in co-infections decreased host growth and survival. This research reveals that time lags between co-infections can affect parasite loads, in line with priority effects theory. As co-infections in the field are unlikely to be simultaneous, an understanding of when co-infections are impacted by time lags between parasite exposures may play a major role in controlling problematic co-infections.
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Affiliation(s)
- Chloe Ramsay
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556, USA
| | - Jason R Rohr
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556, USA
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19
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Cold water reduces the severity of parasite-inflicted damage: support for wintertime recuperation in aquatic hosts. Oecologia 2021; 195:155-161. [PMID: 33387006 DOI: 10.1007/s00442-020-04818-2] [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: 10/30/2019] [Accepted: 12/04/2020] [Indexed: 10/22/2022]
Abstract
The reduction in host fitness caused by parasite infections (virulence) depends on infection intensity and the degree of damage caused per parasite. Environmental conditions can shape both virulence components, but in contrast to infection intensity, environmental impacts on per-parasite damage are poorly understood. Here, we studied the effect of ambient temperature on per-parasite damage, which is jointly determined by the ability of parasites to induce harm (per-parasite pathogenicity) and the ability of hosts to limit damage (tolerance). We experimentally exposed two salmonid species, Atlantic salmon (Salmo salar) and sea trout (Salmo trutta), to replicated genotypes of the eye fluke Diplostomum pseudospathaceum. After development of health damage (eye cataracts) in warm water (16 °C) during the first 12 weeks post exposure, we maintained the fish at either 5 °C (cold water) or 16 °C for another 8 weeks and quantified changes in cataracts as a function of parasite load. We found that per-parasite damage was reduced in cold compared to warm water, suggesting that cold temperatures improved host health. Per-parasite damage was also affected by parasite genotype and host species, but these effects did not change with temperature. Our findings suggest that cold-water seasons, which are often neglected in host-parasite studies due to low infection risk, could allow hosts to recuperate and thus, may have important implications for the ecology and epidemiology of parasite infections.
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20
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Ohmer MEB, Costantini D, Czirják GÁ, Downs CJ, Ferguson LV, Flies A, Franklin CE, Kayigwe AN, Knutie S, Richards-Zawacki CL, Cramp RL. Applied ecoimmunology: using immunological tools to improve conservation efforts in a changing world. CONSERVATION PHYSIOLOGY 2021; 9:coab074. [PMID: 34512994 PMCID: PMC8422949 DOI: 10.1093/conphys/coab074] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/27/2021] [Accepted: 08/09/2021] [Indexed: 05/11/2023]
Abstract
Ecoimmunology is a rapidly developing field that explores how the environment shapes immune function, which in turn influences host-parasite relationships and disease outcomes. Host immune defence is a key fitness determinant because it underlies the capacity of animals to resist or tolerate potential infections. Importantly, immune function can be suppressed, depressed, reconfigured or stimulated by exposure to rapidly changing environmental drivers like temperature, pollutants and food availability. Thus, hosts may experience trade-offs resulting from altered investment in immune function under environmental stressors. As such, approaches in ecoimmunology can provide powerful tools to assist in the conservation of wildlife. Here, we provide case studies that explore the diverse ways that ecoimmunology can inform and advance conservation efforts, from understanding how Galapagos finches will fare with introduced parasites, to using methods from human oncology to design vaccines against a transmissible cancer in Tasmanian devils. In addition, we discuss the future of ecoimmunology and present 10 questions that can help guide this emerging field to better inform conservation decisions and biodiversity protection. From better linking changes in immune function to disease outcomes under different environmental conditions, to understanding how individual variation contributes to disease dynamics in wild populations, there is immense potential for ecoimmunology to inform the conservation of imperilled hosts in the face of new and re-emerging pathogens, in addition to improving the detection and management of emerging potential zoonoses.
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Affiliation(s)
- Michel E B Ohmer
- Living Earth Collaborative, Washington University in St. Louis, MO 63130, USA
| | - David Costantini
- Unité Physiologie Moléculaire et Adaptation (PhyMA), Muséum National d’Histoire Naturelle, CNRS, 57 Rue Cuvier, CP32, 75005, Paris, France
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - Cynthia J Downs
- Department of Environmental Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Laura V Ferguson
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Andy Flies
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
| | - Ahab N Kayigwe
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Sarah Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06268, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, CT 06268, USA
| | | | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
- Corresponding author: School of Biological Sciences, The University of Queensland, Queensland 4072, Australia.
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21
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Hayward AD, Skuce PJ, McNeilly TN. Tolerance of liver fluke infection varies between breeds and producers in beef cattle. Animal 2020; 15:100126. [PMID: 33712215 DOI: 10.1016/j.animal.2020.100126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/28/2020] [Accepted: 11/03/2020] [Indexed: 12/15/2022] Open
Abstract
Liver flukes (Fasciola spp.) are important helminth parasites of livestock globally and cause substantial reductions in health and productivity of beef cattle. Attempts to control fluke have been thwarted by the difficulty of vaccine design, the evolution of flukicide resistance and the need to control the intermediate snail host. Mechanisms to reduce the impact of parasites on animal performance have typically focused on promoting host resistance - defined as the ability of the host to kill and remove the parasite from its system - and such strategies include improving protein nutrition or selective breeding for resistance. Organisms, however, have another broad mechanism for mitigating the impact of parasites: they can show tolerance, defined as the ability to maintain health or performance under increasing parasite burden. Tolerance has been studied in the plant literature for over a century, but there are very few empirical studies of parasite tolerance in livestock. In this study, we used data collected from >90 000 beef cattle to estimate the impact of the severity of liver fluke infection on performance and variation in tolerance of fluke. Severity of liver fluke infection was estimated using liver "fibrosis score" on a scale of 0-3 and performance estimated as (1) age at slaughter and (2) daily dead weight gain. Animals with higher fibrosis scores were slaughtered around 2 weeks later than animals with no fluke and gained around 10 g less weight per day. There was also considerable variation in these effects of fibrosis score, such that animals from different producers and breeds varied in their tolerance of fluke infection. While breeds did not vary in the association between fibrosis and age at slaughter, there was considerable variation among producers: high fibrosis score delayed slaughter by up to 50 days in some producers, but not at all in others. Meanwhile, there was support for variation in the slope of daily dead weight gain on fibrosis score among both breeds and producers, with some unaffected by high fluke scores and some breeds and producers experiencing a 20 g/day lower weight gain under high fluke scores. Our results point to the potential for both environmental and genetic variation in tolerance of liver fluke in cattle, paving the way for quantitative genetic and nutritional research into the feasibility of promoting tolerance as a disease mitigation strategy.
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Affiliation(s)
- A D Hayward
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK..
| | - P J Skuce
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK
| | - T N McNeilly
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK
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22
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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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23
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Laghzaoui EM, Abbad A, El Mouden EH. Host-parasite association of Placobdella costata (Glossiphoniidae: Hirudinea) and Mauremys leprosa (Geoemydidae: Testudinoidea) in aquatic ecosystems of Morocco. Parasitol Res 2020; 119:3459-3467. [PMID: 32677002 DOI: 10.1007/s00436-020-06809-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 07/08/2020] [Indexed: 11/24/2022]
Abstract
Emys orbicularis (Linnaeus, 1758) was considered as a specific host of Placobdella costata (Fr. Mûller, 1846). However, since the parasite was recorded from outside the distribution area of its host, some authors suggested a possible relationship with other hosts. Although two accidental associations were found with another turtle, Mauremys leprosa (Schweigger, 1812), the obtained data remain insufficient to better understand this discovered host-parasite ecological system. In this context, the present study was carried out to evaluate the relationship between the Mediterranean pond turtle, M. leprosa, and the freshwater rhynchobdellid leech, P. costata (Hirudinida: Glossiphoniidae), in aquatic ecosystems of Morocco. During the period from April to June 2018, we found leeches attached to turtles in five out of 30 populations sampled with a prevalence of infection significantly higher in adult than that in juvenile turtles. Moreover, the males are the most infested with 51% of the total, followed by females (33.3%) and juveniles (15.7%). The obtained results indicated that 51 turtles were infested by 139 leeches with a mean intensity of infestation of 4.17 ± 0.47 leeches/turtle (up to 10 leeches/turtle). It was higher in males than that in females in almost all sites. The posterior limbs are the most preferred attachment site, and the body condition of turtles was not affected by the intensity of infestation but it is rather a function of altitude. Our findings proved that M. leprosa-P. costata association is more than accidental and that M. leprosa is rather the main host of P. costata in aquatic ecosystems of Morocco.
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Affiliation(s)
- El-Mustapha Laghzaoui
- Laboratory of Water, Biodiversity and Climatic Change, Faculty of Sciences, Semlalia, Cadi Ayyad University, Marrakech, Morocco
| | - Abdelaziz Abbad
- Laboratory of Microbial Biotechnologies, Agrosciences and Environment, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech, Morocco
| | - El Hassan El Mouden
- Laboratory of Water, Biodiversity and Climatic Change, Faculty of Sciences, Semlalia, Cadi Ayyad University, Marrakech, Morocco.
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24
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Roznik EA, Surbaugh KL, Cano N, Rohr JR. Elucidating mechanisms of invasion success: effects of parasite removal on growth and survival rates of invasive and native frogs. J Appl Ecol 2020; 57:1078-1088. [PMID: 33071307 DOI: 10.1111/1365-2664.13634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Identifying the mechanisms underlying biological invasions can inform the management of invasive species. The enemy release hypothesis (ERH) suggests that invasive species have a competitive advantage in their introduced range because they leave behind many of their predators and parasites from their native range, allowing them to shift resources from defenses to growth, reproduction, and dispersal. Many studies have demonstrated that invasive species have fewer parasites than their native counterparts, but few studies have tested whether the loss of these natural enemies appears to be a primary driver of the invasion process.To test the ERH, we conducted a mark-recapture study in which we used an anthelmintic drug to successfully reduce parasitic worms in invasive Cuban treefrogs (Osteopilus septentrionalis) and native treefrogs (Hyla spp.) at half of 12 wetlands, marking nearly 4,200 frogs. If the ERH is supported, we would expect that treating for parasitic worms would have a greater benefit to native than invasive hosts.Growth and survival rates of invasive and native treefrogs responded similarly to the anthelmintic treatment, suggesting that the Cuban treefrog's release from parasitic worms does not appear to significantly contribute to its invasiveness in established areas. Instead, it appears that the overall faster rates of growth and maturation, higher survival rates, and larger body sizes of Cuban treefrogs that we observed may contribute to their expansion and proliferation.Synthesis and applications. Although Cuban treefrogs have a lower diversity of parasitic worms in their invasive than native range, this does not appear to significantly contribute to their invasion success in areas where they have been established for more than 20 years. This suggests that any manipulation of parasites in invasive or native hosts would not be an effective method of controlling Cuban treefrogs or reducing their impacts. Further research into other hypotheses is needed to explain the Cuban treefrog's success and help guide management actions to reduce their spread and negative impacts. Our study demonstrates that enemy release may not be a primary driver of invasiveness, highlighting the need for more experimental tests of the enemy release hypothesis to examine its generality.
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Affiliation(s)
- Elizabeth A Roznik
- Department of Integrative Biology, University of South Florida, Tampa, Florida 33620, USA.,Department of Conservation and Research, Memphis Zoo, Memphis, Tennessee 38112, USA
| | - Kerri L Surbaugh
- Department of Integrative Biology, University of South Florida, Tampa, Florida 33620, USA
| | - Natalia Cano
- Department of Integrative Biology, University of South Florida, Tampa, Florida 33620, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, Florida 33620, USA.,Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA
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25
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Knutie SA. Food supplementation affects gut microbiota and immunological resistance to parasites in a wild bird species. J Appl Ecol 2020. [DOI: 10.1111/1365-2664.13567] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Sarah A. Knutie
- Department of Ecology and Evolutionary Biology University of Connecticut Storrs CT USA
- Institute for Systems Genomics University of Connecticut Storrs CT USA
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26
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Methling C, Douda K, Reichard M. Intensity-dependent energetic costs in a reciprocal parasitic relationship. Oecologia 2019; 191:285-294. [PMID: 31494712 DOI: 10.1007/s00442-019-04504-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 09/04/2019] [Indexed: 01/05/2023]
Abstract
Parasitic infections elicit host defences that pose energetic trade-offs with other fitness-related traits. Bitterling fishes and unionid mussels are involved in a two-way parasitic interaction. Bitterling exploit mussels by ovipositing into their gills. In turn, mussel larvae (glochidia) develop on the epidermis and gills of fish. Hosts have evolved behavioural responses to reduce parasite load, suggesting that glochidia and bitterling parasitism are costly. We examined the energetic cost of parasitism on both sides of this relationship. We used intermittent flow-through respirometry to measure (1) standard metabolic rate (SMR) of individual duck mussels Anodonta anatina (a common bitterling host) before and during infection by embryos of the European bitterling Rhodeus amarus, and (2) SMR and maximum oxygen uptake (MO2max) of individual R. amarus before and during infection with glochidia of the Chinese pond mussel Sinanodonta woodiana (a mussel species that successfully infects bitterling). As predicted, we observed an increase in mussel SMR when infected by bitterling embryos and an increased SMR in glochidia-infected bitterling, though this was significantly mediated by the time post-infection. Contrary to our predictions, glochidia infection did not impair MO2max and the number of glochidia attached to gills positively (rather than negatively) correlated with MO2max. The results suggest that tolerance is the prevailing coping mechanism for both fish and mussels when infected, while resistance mechanisms appear to be confined to the behavioural level.
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Affiliation(s)
- Caroline Methling
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, 603 65, Brno, Czech Republic
| | - Karel Douda
- Department of Zoology and Fisheries, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Martin Reichard
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, 603 65, Brno, Czech Republic.
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27
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Rohr JR, Barrett CB, Civitello DJ, Craft ME, Delius B, DeLeo GA, Hudson PJ, Jouanard N, Nguyen KH, Ostfeld RS, Remais JV, Riveau G, Sokolow SH, Tilman D. Emerging human infectious diseases and the links to global food production. NATURE SUSTAINABILITY 2019; 2:445-456. [PMID: 32219187 PMCID: PMC7091874 DOI: 10.1038/s41893-019-0293-3] [Citation(s) in RCA: 211] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 04/17/2019] [Indexed: 05/07/2023]
Abstract
Infectious diseases are emerging globally at an unprecedented rate while global food demand is projected to increase sharply by 2100. Here, we synthesize the pathways by which projected agricultural expansion and intensification will influence human infectious diseases and how human infectious diseases might likewise affect food production and distribution. Feeding 11 billion people will require substantial increases in crop and animal production that will expand agricultural use of antibiotics, water, pesticides and fertilizer, and contact rates between humans and both wild and domestic animals, all with consequences for the emergence and spread of infectious agents. Indeed, our synthesis of the literature suggests that, since 1940, agricultural drivers were associated with >25% of all - and >50% of zoonotic - infectious diseases that emerged in humans, proportions that will likely increase as agriculture expands and intensifies. We identify agricultural and disease management and policy actions, and additional research, needed to address the public health challenge posed by feeding 11 billion people.
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Affiliation(s)
- Jason R. Rohr
- Department of Biological Sciences, Eck Institute for Global Health, and Environmental Change Initiative, University of Notre Dame, Notre Dame, IN USA
- Department of Integrative Biology, University of South Florida, Tampa, FL USA
| | | | | | - Meggan E. Craft
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN USA
| | - Bryan Delius
- Department of Integrative Biology, University of South Florida, Tampa, FL USA
| | - Giulio A. DeLeo
- Department of Biology and Woods Institute for the Environment, Hopkins Marine Station, Stanford University, Pacific Grove, CA USA
| | - Peter J. Hudson
- Center for Infectious Disease Dynamics, Pennsylvania State University, College Station, PA USA
| | - Nicolas Jouanard
- Laboratoire de Recherches Biomédicales, Espoir pour la Santé, Saint-Louis, Senegal
| | - Karena H. Nguyen
- Department of Integrative Biology, University of South Florida, Tampa, FL USA
| | | | - Justin V. Remais
- Division of Environmental Health Sciences, University of California, Berkeley, Berkeley, CA USA
| | - Gilles Riveau
- Laboratoire de Recherches Biomédicales, Espoir pour la Santé, Saint-Louis, Senegal
| | - Susanne H. Sokolow
- Department of Biology and Woods Institute for the Environment, Hopkins Marine Station, Stanford University, Pacific Grove, CA USA
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA USA
| | - David Tilman
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN USA
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28
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McNew SM, Knutie SA, Goodman GB, Theodosopoulos A, Saulsberry A, Yépez R. J, Bush SE, Clayton DH. Annual environmental variation influences host tolerance to parasites. Proc Biol Sci 2019; 286:20190049. [PMID: 30963843 PMCID: PMC6408884 DOI: 10.1098/rspb.2019.0049] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/06/2019] [Indexed: 12/16/2022] Open
Abstract
When confronted with a parasite or pathogen, hosts can defend themselves by resisting or tolerating the attack. While resistance can be diminished when resources are limited, it is unclear how robust tolerance is to changes in environmental conditions. Here, we investigate the sensitivity of tolerance in a single host population living in a highly variable environment. We manipulated the abundance of an invasive parasitic fly, Philornis downsi, in nests of Galápagos mockingbirds ( Mimus parvulus) over four field seasons and measured host fitness in response to parasitism. Mockingbird tolerance to P. downsi varied significantly among years and decreased when rainfall was limited. Video observations indicate that parental provisioning of nestlings appears key to tolerance: in drought years, mockingbirds likely do not have sufficient resources to compensate for the effects of P. downsi. These results indicate that host tolerance is a labile trait and suggest that environmental variation plays a major role in mediating the consequences of host-parasite interactions.
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Affiliation(s)
- Sabrina M. McNew
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Sarah A. Knutie
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Graham B. Goodman
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | | | - Ashley Saulsberry
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Janai Yépez R.
- Charles Darwin Research Station, Santa Cruz Island, Galápagos, Ecuador
| | - Sarah E. Bush
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Dale H. Clayton
- Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
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29
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Burgan SC, Gervasi SS, Johnson LR, Martin LB. How Individual Variation in Host Tolerance Affects Competence to Transmit Parasites. Physiol Biochem Zool 2019; 92:49-57. [PMID: 30481116 DOI: 10.1086/701169] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Tolerance, or the maintenance of host health or fitness at a given parasite burden, has often been studied in evolutionary and medical contexts, particularly with respect to effects on the evolution of parasite virulence and individual patient outcomes. These bodies of work have provided insight about tolerance for evolutionary phenomena (e.g., virulence) and individual health (e.g., recovering from an infection). However, due to the specific motivations of that work, few studies have considered the ecological ramifications of variation in tolerance, namely, how variation in forms of tolerance could mediate parasite movement through populations and even community-level disease dynamics. Tolerance is most commonly regarded as the relationship between host fitness and parasite burden. However, few if any studies have actually quantified host fitness, instead utilizing proxies of fitness as the response variables to be regressed against parasite burden. Here, we address how attention to the effects of parasite burden on traits that are relevant to host competence (i.e., the ability to amplify parasites to levels transmissible to other hosts/vectors) will enhance our understanding of disease dynamics in nature. We also provide several forms of guidance for how to overcome the challenges of quantifying tolerance in wild organisms.
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30
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Civitello DJ, Allman BE, Morozumi C, Rohr JR. Assessing the direct and indirect effects of food provisioning and nutrient enrichment on wildlife infectious disease dynamics. Philos Trans R Soc Lond B Biol Sci 2019. [PMID: 29531153 DOI: 10.1098/rstb.2017.0101] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Anthropogenic resource supplementation can shape wildlife disease directly by altering the traits and densities of hosts and parasites or indirectly by stimulating prey, competitor or predator species. We first assess the direct epidemiological consequences of supplementation, highlighting the similarities and differences between food provisioning and two widespread forms of nutrient input: agricultural fertilization and aquatic nutrient enrichment. We then review an aquatic disease system and a general model to assess whether predator and competitor species can enhance or overturn the direct effects of enrichment. All forms of supplementation can directly affect epidemics by increasing host population size or altering parasite production within hosts, but food provisioning is most likely to aggregate hosts and increase parasite transmission. However, if predators or competitors increase in response to supplementation, they could alter resource-fuelled outbreaks in focal hosts. We recommend identifying the traits of hosts, parasites or interacting species that best predict epidemiological responses to supplementation and evaluating the relative importance of these direct and indirect mechanisms. Theory and experiments should examine the timing of behavioural, physiological and demographic changes for realistic, variable scenarios of supplementation. A more integrative view of resource supplementation and wildlife disease could yield broadly applicable disease management strategies.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
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Affiliation(s)
- David J Civitello
- Department of Biology, Emory University, 1510 Clifton Road NE, Atlanta, GA 30322, USA .,Graduate Program in Population Biology, Ecology, and Evolution, Emory University, Atlanta, GA 30322, USA
| | - Brent E Allman
- Graduate Program in Population Biology, Ecology, and Evolution, Emory University, Atlanta, GA 30322, USA
| | - Connor Morozumi
- Graduate Program in Population Biology, Ecology, and Evolution, Emory University, Atlanta, GA 30322, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
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31
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Tavalire HF, Beechler BR, Buss PE, Gorsich EE, Hoal EG, le Roex N, Spaan JM, Spaan RS, van Helden PD, Ezenwa VO, Jolles AE. Context-dependent costs and benefits of tuberculosis resistance traits in a wild mammalian host. Ecol Evol 2018; 8:12712-12726. [PMID: 30619576 PMCID: PMC6308860 DOI: 10.1002/ece3.4699] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/02/2018] [Accepted: 10/12/2018] [Indexed: 12/24/2022] Open
Abstract
Disease acts as a powerful driver of evolution in natural host populations, yet individuals in a population often vary in their susceptibility to infection. Energetic trade-offs between immune and reproductive investment lead to the evolution of distinct life history strategies, driven by the relative fitness costs and benefits of resisting infection. However, examples quantifying the cost of resistance outside of the laboratory are rare. Here, we observe two distinct forms of resistance to bovine tuberculosis (bTB), an important zoonotic pathogen, in a free-ranging African buffalo (Syncerus caffer) population. We characterize these phenotypes as "infection resistance," in which hosts delay or prevent infection, and "proliferation resistance," in which the host limits the spread of lesions caused by the pathogen after infection has occurred. We found weak evidence that infection resistance to bTB may be heritable in this buffalo population (h 2 = 0.10) and comes at the cost of reduced body condition and marginally reduced survival once infected, but also associates with an overall higher reproductive rate. Infection-resistant animals thus appear to follow a "fast" pace-of-life syndrome, in that they reproduce more quickly but die upon infection. In contrast, proliferation resistance had no apparent costs and was associated with measures of positive host health-such as having a higher body condition and reproductive rate. This study quantifies striking phenotypic variation in pathogen resistance and provides evidence for a link between life history variation and a disease resistance trait in a wild mammalian host population.
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Affiliation(s)
- Hannah F. Tavalire
- Department of Integrative BiologyOregon State UniversityCorvallisOregon
- The Institute of Ecology and EvolutionUniversity of OregonEugeneOregon
- Present address:
Prevention Science InstituteUniversity of OregonEugeneOregon
- Present address:
Institute of Ecology and EvolutionUniversity of OregonEugeneOregon
| | | | | | - Erin E. Gorsich
- College of Veterinary MedicineOregon State UniversityCorvallisOregon
- Present address:
Erin E. Gorsich, Zeeman Institute: Systems Biology and Infectious Disease Epidemiology Research (SBIDER)University of WarwickCoventryUK
- Present address:
School of Life SciencesUniversity of WarwickCoventryUK
| | - Eileen G. Hoal
- South African Medical Research Council, DST/NRF Centre of Excellence for Biomedical TB Research, Division of Molecular Biology and Human Genetics, Faculty of Health SciencesStellenbosch UniversityTygerbergSouth Africa
| | - Nikki le Roex
- South African Medical Research Council, DST/NRF Centre of Excellence for Biomedical TB Research, Division of Molecular Biology and Human Genetics, Faculty of Health SciencesStellenbosch UniversityTygerbergSouth Africa
| | - Johannie M. Spaan
- Department of Integrative BiologyOregon State UniversityCorvallisOregon
| | - Robert S. Spaan
- Department of Fisheries and WildlifeOregon State UniversityCorvallisOregon
| | - Paul D. van Helden
- South African Medical Research Council, DST/NRF Centre of Excellence for Biomedical TB Research, Division of Molecular Biology and Human Genetics, Faculty of Health SciencesStellenbosch UniversityTygerbergSouth Africa
| | - Vanessa O. Ezenwa
- Odum School of Ecology and Department of Infectious Diseases, College of Veterinary MedicineUniversity of GeorgiaAthensGeorgia
| | - Anna E. Jolles
- Department of Integrative BiologyOregon State UniversityCorvallisOregon
- College of Veterinary MedicineOregon State UniversityCorvallisOregon
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32
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Ruiz-Aravena M, Jones ME, Carver S, Estay S, Espejo C, Storfer A, Hamede RK. Sex bias in ability to cope with cancer: Tasmanian devils and facial tumour disease. Proc Biol Sci 2018; 285:rspb.2018.2239. [PMID: 30464069 DOI: 10.1098/rspb.2018.2239] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 11/01/2018] [Indexed: 02/07/2023] Open
Abstract
Knowledge of the ecological dynamics between hosts and pathogens during the initial stages of disease emergence is crucial to understanding the potential for evolution of new interspecific interactions. Tasmanian devil (Sarcophilus harrisii) populations have declined precipitously owing to infection by a transmissible cancer (devil facial tumour disease, DFTD) that emerged approximately 20 years ago. Since the emergence of DFTD, and as the disease spreads across Tasmania, the number of devils has dropped up to 90% across 80% of the species's distributional range. As a result, the disease is expected to act as a strong selective force on hosts to develop mechanisms of tolerance and/or resistance to the infection. We assessed the ability of infected devils to cope with infection, which translates into host tolerance to the cancer, by using the reaction norm of the individual body condition by tumour burden. We found that body condition of infected hosts is negatively affected by cancer progression. Males and females presented significant differences in their tolerance levels to infection, with males suffering declines of up to 25% of their body condition, in contrast to less than 5% in females. Sex-related differences in tolerance to cancer progression may select for changes in life-history strategies of the host and could also alter the selective environment for the tumours.
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Affiliation(s)
| | - Menna E Jones
- School of Natural Sciences, University of Tasmania, Hobart, Australia
| | - Scott Carver
- School of Natural Sciences, University of Tasmania, Hobart, Australia
| | - Sergio Estay
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile.,Center of Applied Ecology and Sustainability, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Camila Espejo
- School of Medicine, University of Tasmania, Hobart, Australia
| | - Andrew Storfer
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Rodrigo K Hamede
- School of Natural Sciences, University of Tasmania, Hobart, Australia
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33
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Budischak SA, Cressler CE. Fueling Defense: Effects of Resources on the Ecology and Evolution of Tolerance to Parasite Infection. Front Immunol 2018; 9:2453. [PMID: 30429848 PMCID: PMC6220035 DOI: 10.3389/fimmu.2018.02453] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 10/04/2018] [Indexed: 12/29/2022] Open
Abstract
Resource availability is a key environmental constraint affecting the ecology and evolution of species. Resources have strong effects on disease resistance, but they can also affect the other main parasite defense strategy, tolerance. A small but growing number of animal studies are beginning to investigate the effects of resources on tolerance phenotypes. Here, we review how resources affect tolerance strategies across animal taxa ranging from fruit flies to frogs to mice. Surprisingly, resources (quality and quantity) can increase or reduce tolerance, dependent upon the particular host-parasite system. To explore this seeming contradiction, we recast predictions of models of sterility tolerance and mortality tolerance in a resource-dependent context. Doing so reveals that resources can have very different epidemiological and evolutionary effects, depending on what aspects of the tolerance phenotype are affected. Thus, it is critical to consider both sterility and mortality in future empirical studies of how behavioral and environmental resource availability affect tolerance to infection.
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Affiliation(s)
- Sarah A. Budischak
- W. M. Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA, United States
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States
| | - Clayton E. Cressler
- School of Biological Sciences, University of Nebraska, Lincoln, NE, United States
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34
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35
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Knutie SA. Relationships among introduced parasites, host defenses, and gut microbiota of Galapagos birds. Ecosphere 2018. [DOI: 10.1002/ecs2.2286] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Sarah A. Knutie
- Department of Ecology and Evolutionary Biology University of Connecticut Storrs Connecticut 06269 USA
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36
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Becker DJ, Streicker DG, Altizer S, Derryberry E. Using host species traits to understand the consequences of resource provisioning for host-parasite interactions. J Anim Ecol 2018; 87:511-525. [PMID: 29023699 PMCID: PMC5836909 DOI: 10.1111/1365-2656.12765] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 08/31/2017] [Indexed: 12/17/2022]
Abstract
Supplemental food provided to wildlife by human activities can be more abundant and predictable than natural resources, and subsequent changes in wildlife ecology can have profound impacts on host-parasite interactions. Identifying traits of species associated with increases or decreases in infection outcomes with resource provisioning could improve assessments of wildlife most prone to disease risks in changing environments. We conducted a phylogenetic meta-analysis of 342 host-parasite interactions across 56 wildlife species and three broad taxonomic groups of parasites to identify host-level traits that influence whether provisioning is associated with increases or decreases in infection. We predicted dietary generalists that capitalize on novel food would show greater infection in provisioned habitats owing to population growth and food-borne exposure to contaminants and parasite infectious stages. Similarly, species with fast life histories could experience stronger demographic and immunological benefits from provisioning that affect parasite transmission. We also predicted that wide-ranging and migratory behaviours could increase infection risks with provisioning if concentrated and non-seasonal foods promote dense aggregations that increase exposure to parasites. We found that provisioning increased infection with bacteria, viruses, fungi and protozoa (i.e. microparasites) most for wide-ranging, dietary generalist host species. Effect sizes for ectoparasites were also highest for host species with large home ranges but were instead lowest for dietary generalists. In contrast, the type of provisioning was a stronger correlate of infection outcomes for helminths than host species traits. Our analysis highlights host traits related to movement and feeding behaviour as important determinants of whether species experience greater infection with supplemental feeding. These results could help prioritize monitoring wildlife with particular trait profiles in anthropogenic habitats to reduce infectious disease risks in provisioned populations.
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Affiliation(s)
- Daniel J. Becker
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
| | - Daniel G. Streicker
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- MRC‐University of Glasgow Centre for Virus ResearchGlasgowUK
| | - Sonia Altizer
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
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37
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Beechler BR, Jolles AE, Budischak SA, Corstjens PLAM, Ezenwa VO, Smith M, Spaan RS, van Dam GJ, Steinauer ML. Host immunity, nutrition and coinfection alter longitudinal infection patterns of schistosomes in a free ranging African buffalo population. PLoS Negl Trop Dis 2017; 11:e0006122. [PMID: 29253882 PMCID: PMC5755937 DOI: 10.1371/journal.pntd.0006122] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 01/05/2018] [Accepted: 11/20/2017] [Indexed: 11/19/2022] Open
Abstract
Schistosomes are trematode parasites of global importance, causing infections in millions of people, livestock, and wildlife. Most studies on schistosomiasis, involve human subjects; as such, there is a paucity of longitudinal studies investigating parasite dynamics in the absence of intervention. As a consequence, despite decades of research on schistosomiasis, our understanding of its ecology in natural host populations is centered around how environmental exposure and acquired immunity influence acquisition of parasites, while very little is known about the influence of host physiology, coinfection and clearance in the absence of drug treatment. We used a 4-year study in free-ranging African buffalo to investigate natural schistosome dynamics. We asked (i) what are the spatial and temporal patterns of schistosome infections; (ii) how do parasite burdens vary over time within individual hosts; and (iii) what host factors (immunological, physiological, co-infection) and environmental factors (season, location) explain patterns of schistosome acquisition and loss in buffalo? Schistosome infections were common among buffalo. Microgeographic structure explained some variation in parasite burdens among hosts, indicating transmission hotspots. Overall, parasite burdens ratcheted up over time; however, gains in schistosome abundance in the dry season were partially offset by losses in the wet season, with some hosts demonstrating complete clearance of infection. Variation among buffalo in schistosome loss was associated with immunologic and nutritional factors, as well as co-infection by the gastrointestinal helminth Cooperia fuelleborni. Our results demonstrate that schistosome infections are surprisingly dynamic in a free-living mammalian host population, and point to a role for host factors in driving variation in parasite clearance, but not parasite acquisition which is driven by seasonal changes and spatial habitat utilization. Our study illustrates the power of longitudinal studies for discovering mechanisms underlying parasite dynamics in individual animals and populations.
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Affiliation(s)
- Brianna R. Beechler
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Anna E. Jolles
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America
| | - Sarah A. Budischak
- Odum School of Ecology, University of Georgia, Athens, GA, United States of America
| | - Paul L. A. M. Corstjens
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Vanessa O. Ezenwa
- Odum School of Ecology, University of Georgia, Athens, GA, United States of America
- College of Veterinary Medicine, University of Georgia, Athens, GA, United States of America
| | - Mireya Smith
- College of Veterinary Medicine, University of Georgia, Athens, GA, United States of America
| | - Robert S. Spaan
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, United States of America
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michelle L. Steinauer
- College of Osteopathic Medicine of the PNW, Western University of Health Sciences, Lebanon, OR, United States of America
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38
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Knutie SA, Gabor CR, Kohl KD, Rohr JR. Do host-associated gut microbiota mediate the effect of an herbicide on disease risk in frogs? J Anim Ecol 2017; 87:489-499. [PMID: 29030867 DOI: 10.1111/1365-2656.12769] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 09/21/2017] [Indexed: 12/21/2022]
Abstract
Environmental stressors, such as pollutants, can increase disease risk in wildlife. For example, the herbicide atrazine affects host defences (e.g. resistance and tolerance) of the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), but the mechanisms for these associations are not entirely clear. Given that pollutants can alter the gut microbiota of hosts, which in turn can affect their health and immune systems, one potential mechanism by which pollutants could increase infection risk is by influencing host-associated microbiota. Here, we test whether early-life exposure to the estimated environmental concentration (EEC; 200 μg/L) of atrazine affects the gut bacterial composition of Cuban tree frog (Osteopilus septentrionalis) tadpoles and adults and whether any atrazine-induced change in community composition might affect host defences against Bd. We also determine whether early-life changes in the stress hormone corticosterone affect gut microbiota by experimentally inhibiting corticosterone synthesis with metyrapone. With the exception of changing the relative abundances of two bacterial genera in adulthood, atrazine did not affect gut bacterial diversity or community composition of tadpoles (in vivo or in vitro) or adults. Metyrapone did not significantly affect bacterial diversity of tadpoles, but significantly increased bacterial diversity of adults. Gut bacterial diversity during Bd exposure did not predict host tolerance or resistance to Bd intensity in tadpoles or adults. However, early-life bacterial diversity negatively predicted Bd intensity as adult frogs. Specifically, Bd intensity as adults was associated negatively with the relative abundance of phylum Fusobacteria in the guts of tadpoles. Our results suggest that the effect of atrazine on Bd infection risk is not mediated by host-associated microbiota because atrazine does not affect microbiota of tadpoles or adults. However, host-associated microbes seem important in host resistance to Bd because the early-life microbiota, during immune system development, predicted later-life infection risk with Bd. Overall, our study suggests that increasing gut bacterial diversity and relative abundances of Fusobacteria might have lasting positive effects on amphibian health.
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Affiliation(s)
- Sarah A Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA
| | - Caitlin R Gabor
- Department of Biology, Texas State University, San Marcos, TX, USA
| | - Kevin D Kohl
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
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Knutie SA, Shea LA, Kupselaitis M, Wilkinson CL, Kohl KD, Rohr JR. Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs. Integr Comp Biol 2017; 57:732-742. [PMID: 28662573 PMCID: PMC5886343 DOI: 10.1093/icb/icx028] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against parasitic gut worms of frogs, but these effects depend on the stage of the host and infection, respectively.
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Affiliation(s)
- Sarah A. Knutie
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Lauren A. Shea
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Marinna Kupselaitis
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | | | - Kevin D. Kohl
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jason R. Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
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Early-life disruption of amphibian microbiota decreases later-life resistance to parasites. Nat Commun 2017; 8:86. [PMID: 28729558 PMCID: PMC5519754 DOI: 10.1038/s41467-017-00119-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 06/02/2017] [Indexed: 02/08/2023] Open
Abstract
Changes in the early-life microbiota of hosts might affect infectious disease risk throughout life, if such disruptions during formative times alter immune system development. Here, we test whether an early-life disruption of host-associated microbiota affects later-life resistance to infections by manipulating the microbiota of tadpoles and challenging them with parasitic gut worms as adults. We find that tadpole bacterial diversity is negatively correlated with parasite establishment in adult frogs: adult frogs that had reduced bacterial diversity as tadpoles have three times more worms than adults without their microbiota manipulated as tadpoles. In contrast, adult bacterial diversity during parasite exposure is not correlated with parasite establishment in adult frogs. Thus, in this experimental setup, an early-life disruption of the microbiota has lasting reductions on host resistance to infections, which is possibly mediated by its effects on immune system development. Our results support the idea that preventing early-life disruption of host-associated microbiota might confer protection against diseases later in life. Early-life microbiota alterations can affect infection susceptibility later in life, in animal models. Here, Knutie et al. show that manipulating the microbiota of tadpoles leads to increased susceptibility to parasitic infection in adult frogs, in the absence of substantial changes in the adults’ microbiota.
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