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Barroso P, Acevedo P, Risalde MA, García-Bocanegra I, Montoro V, Martínez-Padilla AB, Torres MJ, Soriguer RC, Vicente J. Co-exposure to pathogens in wild ungulates from Doñana National Park, South Spain. Res Vet Sci 2023; 155:14-28. [PMID: 36608374 DOI: 10.1016/j.rvsc.2022.12.009] [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: 09/27/2022] [Revised: 11/14/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Multiple infections or co-exposure to pathogens should be considered systematically in wildlife to better understand the ecology and evolution of host-pathogen relationships, so as to better determine the potential use of multiple pathogens as indicators to guide health management. We describe the pattern of co-exposure to several pathogens (i.e. simultaneous positive diagnosis to pathogens in an individual considering Mycobacterium tuberculosis complex lesions, and the presence of antibodies against Toxoplasma gondii, bluetongue virus, and hepatitis E virus) and assessed their main drivers in the wild ungulate community from Doñana National Park (red deer, fallow deer, and wild boar) for a 13-years longitudinal study. The lower-than-expected frequency of co-exposure registered in all species was consistent with non-mutually exclusive hypotheses (e.g. antagonism or disease-related mortality), which requires further investigation. The habitat generalist species (red deer and wild boar) were exposed to a greater diversity of pathogens (frequency of co-exposure around 50%) and/or risk factors than fallow deer (25.0% ± CI95% 4.9). Positive relationships between pathogens were evidenced, which may be explained by common risk factors favouring exposure. The specific combination of pathogens in individuals was mainly driven by different groups of factors (individual, environmental, stochastic, and populational), as well as its interaction, defining a complex eco-epidemiological landscape. To deepen into the main determinants and consequences of co-infections in a complex assemblage of wild hosts, and at the interface with humans and livestock, there also is needed to expand the range of pathogens and compare diverse assemblages of hosts under different environmental and management circumstances.
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Affiliation(s)
- Patricia Barroso
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC-UCLM-JCCM, 13071 Ciudad Real, Spain.
| | - Pelayo Acevedo
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC-UCLM-JCCM, 13071 Ciudad Real, Spain
| | - María A Risalde
- Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ). Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad de Córdoba, Córdoba, Spain; Centro de Investigación Biomédica en Red Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain; Unidad de Enfermedades Infecciosas, Grupo de Virología Clínica y Zoonosis, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía, Córdoba, Spain
| | - Ignacio García-Bocanegra
- Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ). Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad de Córdoba, Córdoba, Spain; Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ), Departamento de Sanidad Animal, Universidad de Córdoba, Córdoba, Spain
| | - Vidal Montoro
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC-UCLM-JCCM, 13071 Ciudad Real, Spain; Escuela Técnica Superior de Ingenieros Agrónomos, UCLM, 13071 Ciudad Real, Spain
| | | | - María J Torres
- Departamento de Microbiología, Universidad de Sevilla, 41009 Seville, Spain
| | - Ramón C Soriguer
- Estación Biológica Doñana, CSIC, 41092 Seville, Spain; Centro de Investigación Biomédica en Red: Epidemiología y Salud Pública (CIBERESP). Instituto de Salud Carlos III, Madrid, Spain
| | - Joaquín Vicente
- Instituto de Investigación en Recursos Cinegéticos (IREC) CSIC-UCLM-JCCM, 13071 Ciudad Real, Spain; Escuela Técnica Superior de Ingenieros Agrónomos, UCLM, 13071 Ciudad Real, Spain
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2
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Schai-Braun SC, Posautz A, Alves PC, Hackländer K. Gastrointestinal parasite infestation in the alpine mountain hare ( Lepus timidus varronis): Are abiotic environmental factors such as elevation, temperature and precipitation affecting prevalence of parasite species? INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2019; 9:202-208. [PMID: 31193935 PMCID: PMC6545328 DOI: 10.1016/j.ijppaw.2019.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/27/2019] [Accepted: 05/28/2019] [Indexed: 01/23/2023]
Abstract
Information concerning factors regulating Alpine mountain hare (Lepus timidus varronis) populations such as host-parasite interactions is missing as only a few parasitological surveys exist of this subspecies. Parasites are not only dependent on their host but also on suitable environmental conditions for infestation. Abiotic environmental factors have an important regulating role on parasites in mammals. It is estimated that the elevation range of parasites is likely to shift in response to alternate host movement and changes in climate. Here we assess the parasitic infestation in the Alpine mountain hare by analysing the parasites in faeces and comparing the parasite infestation at different elevation ranges and at varied weather conditions for two years in the Austrian Alps. Almost half of the faecal samples were free of parasites (46.2%, n = 52). Most frequent was the infection by Coccidia (46.2%), whereas stomach intestine strongylids, Trichuris spp, and Cestoda were only found in 9.6% of all faeces. Hence, only Coccidia may be prevalent enough to regulate Alpine mountain hare populations in the Austrian Alps. Elevation had a significant positive effect on the infection of animals by Trichuris spp, whereas temperature had a significant negative effect on the infection by any parasite traceable in faeces and, when looking at the parasite groups individually, on Coccidia. Almost half of the Alpine mountain hare faecal samples were free of parasites. Coccidia was more frequent in our hare faeces than in other examined populations. Stomach intestine strongylids and Cestoda were only found in 9.6% of our samples. Only Coccidia may be prevalent enough to regulate this hare population. Temperature had a significant negative effect on the incidence of any parasite in the faecal samples.
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Affiliation(s)
- Stéphanie C Schai-Braun
- Institute of Wildlife Biology and Game Management, Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Gregor-Mendel-Strasse 33, 1180, Vienna, Austria
| | - Annika Posautz
- Research Institute of Wildlife Ecology, Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Vienna, Austria
| | - Paulo C Alves
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007, Porto, Portugal.,CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Campus de Vairão, 4485-661, Vairão, Portugal
| | - Klaus Hackländer
- Institute of Wildlife Biology and Game Management, Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna, Gregor-Mendel-Strasse 33, 1180, Vienna, Austria
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3
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Whiting JR, Magalhaes IS, Singkam AR, Robertson S, D'Agostino D, Bradley JE, MacColl ADC. A genetics-based approach confirms immune associations with life history across multiple populations of an aquatic vertebrate (Gasterosteus aculeatus). Mol Ecol 2018; 27:3174-3191. [PMID: 29924437 PMCID: PMC6221044 DOI: 10.1111/mec.14772] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 05/10/2018] [Accepted: 05/10/2018] [Indexed: 12/15/2022]
Abstract
Understanding how wild immune variation covaries with other traits can reveal how costs and trade‐offs shape immune evolution in the wild. Divergent life history strategies may increase or alleviate immune costs, helping shape immune variation in a consistent, testable way. Contrasting hypotheses suggest that shorter life histories may alleviate costs by offsetting them against increased mortality, or increase the effect of costs if immune responses are traded off against development or reproduction. We investigated the evolutionary relationship between life history and immune responses within an island radiation of three‐spined stickleback, with discrete populations of varying life histories and parasitism. We sampled two short‐lived, two long‐lived and an anadromous population using qPCR to quantify current immune profile and RAD‐seq data to study the distribution of immune variants within our assay genes and across the genome. Short‐lived populations exhibited significantly increased expression of all assay genes, which was accompanied by a strong association with population‐level variation in local alleles and divergence in a gene that may be involved in complement pathways. In addition, divergence around the eda gene in anadromous fish is likely associated with increased inflammation. A wider analysis of 15 populations across the island revealed that immune genes across the genome show evidence of having diverged alongside life history strategies. Parasitism and reproductive investment were also important sources of variation for expression, highlighting the caution required when assaying immune responses in the wild. These results provide strong, gene‐based support for current hypotheses linking life history and immune variation across multiple populations of a vertebrate model.
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Affiliation(s)
- James R Whiting
- School of Life Sciences, University of Nottingham, University Park, Nottingham, UK.,School of Life Sciences, University of Sussex, Falmer, Brighton, UK
| | - Isabel S Magalhaes
- School of Life Sciences, University of Nottingham, University Park, Nottingham, UK.,Department of Life Sciences, Whitelands College, University of Roehampton, London, UK
| | - Abdul R Singkam
- School of Life Sciences, University of Nottingham, University Park, Nottingham, UK.,Pendidikan Biologi JPMIPA FKIP, University of Bengkulu, Bengkulu, Indonesia
| | - Shaun Robertson
- School of Life Sciences, University of Nottingham, University Park, Nottingham, UK.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Daniele D'Agostino
- School of Life Sciences, University of Nottingham, University Park, Nottingham, UK
| | - Janette E Bradley
- School of Life Sciences, University of Nottingham, University Park, Nottingham, UK
| | - Andrew D C MacColl
- School of Life Sciences, University of Nottingham, University Park, Nottingham, UK
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4
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Schale S, Howe D, Yeargan M, Morrow JK, Graves A, Johnson AL. Protozoal coinfection in horses with equine protozoal myeloencephalitis in the eastern United States. J Vet Intern Med 2018; 32:1210-1214. [PMID: 29633348 PMCID: PMC5980325 DOI: 10.1111/jvim.15127] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 03/01/2018] [Accepted: 03/05/2018] [Indexed: 01/15/2023] Open
Abstract
Background Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis. Hypothesis/Objectives To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites. Animals One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM. Methods Case review. Archived serum and cerebrospinal fluid (CSF) from 101 horses were examined. Inclusion criteria included neurologic disease, antemortem or postmortem diagnosis of EPM or CVSM, and availability of serological results or archived samples for testing. Additional testing for antibodies was performed on serum for T. gondii, as well as serum and CSF for N. hughesi. Results Horses with EPM were more likely than horses with CVSM to have positive immunologic results for S. neurona on serum (95.9% versus 76.9%, P = .0058), CSF (98.0% versus 44.2%, P < .00001), and serum : CSF titer ratio (91.8% versus 0%, P < .00001). Positive results for Neospora and Toxoplasma were uncommon, with total seroprevalence rates of 12.9% and 14.9%, respectively. The proportions of EPM cases testing positive for Neospora and Toxoplasma (16% and 12%) were not different from the proportions of CVSM cases testing positive (10% and 17%, P = .31 and .47, respectively). Conclusion Results do not indicate an important role for protozoal coinfection in EPM in the eastern United States.
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Affiliation(s)
- Sarah Schale
- Department of Clinical Studies, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon
| | - Daniel Howe
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky
| | - Michelle Yeargan
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky
| | | | - Amy Graves
- Equine Diagnostic Solutions, LLC, Lexington, Kentucky
| | - Amy L Johnson
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania
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5
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Stutz WE, Blaustein AR, Briggs CJ, Hoverman JT, Rohr JR, Johnson PTJ. Using multi-response models to investigate pathogen coinfections across scales: insights from emerging diseases of amphibians. Methods Ecol Evol 2018; 9:1109-1120. [PMID: 29861885 PMCID: PMC5978769 DOI: 10.1111/2041-210x.12938] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Associations among parasites affect many aspects of host-parasite dynamics, but a lack of analytical tools has limited investigations of parasite correlations in observational data that are often nested across spatial and biological scales.Here we illustrate how hierarchical, multiresponse modeling can characterize parasite associations by allowing for hierarchical structuring, offering estimates of uncertainty, and incorporating correlational model structures. After introducing the general approach, we apply this framework to investigate coinfections among four amphibian parasites (the trematodes Ribeiroia ondatrae and Echinostoma spp., the chytrid fungus Batrachochytrium dendrobatidis, and ranaviruses) and among >2000 individual hosts, 90 study sites, and five amphibian host species.Ninety-two percent of sites and 80% of hosts supported two or more pathogen species. Our results revealed strong correlations between parasite pairs that varied by scale (from among hosts to among sites) and classification (microparasite versus macroparasite), but were broadly consistent across taxonomically diverse host species. At the host-scale, infection by the trematode R. ondatrae correlated positively with the microparasites, B. dendrobatidis and ranavirus, which were themselves positively associated. However, infection by a second trematode (Echinostoma spp.) correlated negatively with B. dendrobatidis and ranavirus, both at the host- and site-level scales, highlighting the importance of differential relationships between micro- and macroparasites.Given the extensive number of coinfecting symbiont combinations inherent to natural systems, particularly across multiple host species, multiresponse modeling of cross-sectional field data offers a valuable tool to identify a tractable number of hypothesized interactions for experimental testing while accounting for uncertainty and potential sources of co-exposure. For amphibians specifically, the high frequency of co-occurrence and coinfection among these pathogens - each of which is known to impair host fitness or survival - highlights the urgency of understanding parasite associations for conservation and disease management.
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Affiliation(s)
- William E. Stutz
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO 80309-0334
| | - Andrew R. Blaustein
- Integrative Biology, 3029 Cordley Hall, Oregon State University, Corvallis, OR 97331-2914
| | - Cheryl J. Briggs
- Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106-9610
| | - Jason T. Hoverman
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907-2061
| | - Jason R. Rohr
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Avenue, SCA 110, Tampa, FL 33620
| | - Pieter T. J. Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO 80309-0334
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6
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Haskins DL, Hamilton MT, Jones AL, Finger JW, Bringolf RB, Tuberville TD. Accumulation of coal combustion residues and their immunological effects in the yellow-bellied slider (Trachemys scripta scripta). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 224:810-819. [PMID: 28284546 DOI: 10.1016/j.envpol.2017.01.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/03/2017] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
Anthropogenic activities such as industrial processes often produce copious amounts of contaminants that have the potential to negatively impact growth, survival, and reproduction of exposed wildlife. Coal combustion residues (CCRs) represent a major source of pollutants globally, resulting in the release of potentially harmful trace elements such as arsenic (As), cadmium (Cd), and selenium (Se) into the environment. In the United States, CCRs are typically stored in aquatic settling basins that may become attractive nuisances to wildlife. Trace element contaminants, such as CCRs, may pose a threat to biota yet little is known about their sublethal effects on reptiles. To assess the effects of CCR exposure in turtles, we sampled 81 yellow-bellied sliders (Trachemys scripta scripta) in 2014-2015 from CCR-contaminated and uncontaminated reference wetlands located on the Savannah River Site (Aiken, SC, USA). Specific aims were to (1) compare the accumulation of trace elements in T. s. scripta claw and blood samples between reference and CCR-contaminated site types, (2) evaluate potential immunological effects of CCRs via bacterial killing assays and phytohaemagglutinin (PHA) assays, and (3) quantify differences in hemogregarine parasite loads between site types. Claw As, Cd, copper (Cu), and Se (all p ≤ 0.001) and blood As, Cu, Se, and strontium (Sr; p ≤ 0.015) were significantly elevated in turtles from CCR-contaminated wetlands compared to turtles from reference wetlands. Turtles from reference wetlands exhibited lower bacterial killing (p = 0.015) abilities than individuals from contaminated sites but neither PHA responses (p = 0.566) nor parasite loads (p = 0.980) differed by site type. Despite relatively high CCR body burdens, sliders did not exhibit apparent impairment of immunological response or parasite load. In addition, the high correlation between claw and blood concentrations within individuals suggests that nonlethal tissue sampling may be useful for monitoring CCR exposure in turtles.
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Affiliation(s)
- David L Haskins
- Savannah River Ecology Lab, University of Georgia, Drawer E, Aiken, SC 29802, USA; D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA.
| | - Matthew T Hamilton
- Savannah River Ecology Lab, University of Georgia, Drawer E, Aiken, SC 29802, USA; D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
| | - Amanda L Jones
- Savannah River Ecology Lab, University of Georgia, Drawer E, Aiken, SC 29802, USA
| | - John W Finger
- Savannah River Ecology Lab, University of Georgia, Drawer E, Aiken, SC 29802, USA; Dept. of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Robert B Bringolf
- D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
| | - Tracey D Tuberville
- Savannah River Ecology Lab, University of Georgia, Drawer E, Aiken, SC 29802, USA; D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
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7
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Dhondt AA, Dobson AP. Stress Hormones Bring Birds, Pathogens and Mosquitoes Together. Trends Parasitol 2017; 33:339-341. [PMID: 28153740 PMCID: PMC5410392 DOI: 10.1016/j.pt.2017.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/21/2016] [Accepted: 01/03/2017] [Indexed: 02/03/2023]
Abstract
Do stress hormones, such as corticosterone, enhance bird susceptibility to mosquitoes in ways that enhance rates of co-infection? Does this then enhance pathogen emergence?
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Affiliation(s)
- André A Dhondt
- Laboratory of Ornithology, Cornell University,159 Sapsucker Woods Road, Ithaca, NY 14850, USA.
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8
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Bailly J, Garnier S, Khimoun A, Arnoux E, Eraud C, Goret J, Luglia T, Gaucher P, Faivre B. Reduced inflammation in expanding populations of a neotropical bird species. Ecol Evol 2016; 6:7511-7521. [PMID: 28725417 PMCID: PMC5513268 DOI: 10.1002/ece3.2486] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/12/2016] [Accepted: 08/18/2016] [Indexed: 01/29/2023] Open
Abstract
The loss of regulating agents such as parasites is among the most important changes in biotic interactions experienced by populations established in newly colonized areas. Under a relaxed parasite pressure, individuals investing less in costly immune mechanisms might experience a selective advantage and become successful colonizers as they re‐allocate resources to other fitness‐related traits. Accordingly, a refinement of the evolution of increased competitive ability (EICA) hypothesis proposed that immunity of invasive populations has evolved toward a reduced investment in innate immunity, the most costly component of immunity, and an increased humoral immunity that is less costly. Biogeographical approaches comparing populations between native and expansion ranges are particularly relevant in exploring this issue, but remain very scarce. We conducted a biogeographical comparison between populations of Spectacled Thrush (Turdus nudigenis) from the native area (South America) and from the expansion range (Caribbean islands). First, we compared haemosporidian prevalence and circulating haptoglobin (an acute‐phase protein produced during inflammation). Second, we challenged captive birds from both ranges with Escherichia coli lipopolysaccharides (LPS) and measured postchallenge haptoglobin production and body mass change. Birds from the expansion range showed lower haemosporidian prevalence and lower levels of haptoglobin than birds from the native range. In addition, the inflammation elicited by LPS injection and its associated cost in terms of body mass loss were lower in birds from the expansion range than in birds from the native range. In accordance with the enemy release hypothesis, our results suggest that range expansion is associated with a reduced infection risk. Our study also supports the hypothesis that individuals from newly established populations have evolved mechanisms to dampen the inflammatory response and are in accordance with one prediction of the refined EICA hypothesis, proposed to understand biological invasions.
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Affiliation(s)
- Juliette Bailly
- BioGéoSciencesUMR CNRS 6282Univ Bourgogne Franche‐ComtéDijonFrance
| | - Stéphane Garnier
- BioGéoSciencesUMR CNRS 6282Univ Bourgogne Franche‐ComtéDijonFrance
| | - Aurélie Khimoun
- BioGéoSciencesUMR CNRS 6282Univ Bourgogne Franche‐ComtéDijonFrance
| | - Emilie Arnoux
- BioGéoSciencesUMR CNRS 6282Univ Bourgogne Franche‐ComtéDijonFrance
| | - Cyril Eraud
- Office National de la Chasse et de la Faune SauvageCNERA Avifaune migratriceVilliers en BoisFrance
| | - Jean‐Yves Goret
- UMR Ecologie des Forêts de GuyaneKourou CedexGuyane FrançaiseFrance
| | - Thomas Luglia
- Groupe d'Etude et de Protection des Oiseaux de GuyaneCayenneGuyane FrançaiseFrance
| | | | - Bruno Faivre
- BioGéoSciencesUMR CNRS 6282Univ Bourgogne Franche‐ComtéDijonFrance
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9
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Rall G, Knoll LJ. Development of Complex Models to Study Co- and Polymicrobial Infections and Diseases. PLoS Pathog 2016; 12:e1005858. [PMID: 27607188 PMCID: PMC5015861 DOI: 10.1371/journal.ppat.1005858] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Glenn Rall
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of
America
- * E-mail: (GR); (LJK)
| | - Laura J. Knoll
- Department of Medical Microbiology and Immunology, University of
Wisconsin–Madison, Madison, Wisconsin, United States of
America
- * E-mail: (GR); (LJK)
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10
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Martin LB, Burgan SC, Adelman JS, Gervasi SS. Host Competence: An Organismal Trait to Integrate Immunology and Epidemiology. Integr Comp Biol 2016; 56:1225-1237. [DOI: 10.1093/icb/icw064] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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11
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Enriquez GF, Garbossa G, Macchiaverna NP, Argibay HD, Bua J, Gürtler RE, Cardinal MV. Is the infectiousness of dogs naturally infected with Trypanosoma cruzi associated with poly-parasitism? Vet Parasitol 2016; 223:186-94. [PMID: 27198799 DOI: 10.1016/j.vetpar.2016.04.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 04/23/2016] [Accepted: 04/26/2016] [Indexed: 12/11/2022]
Abstract
Interactions among different species of parasites co-infecting the same host could be synergistic or antagonistic. These interactions may modify both the frequency of infected hosts and their infectiousness, and therefore impact on transmission dynamics. This study determined the infectiousness of Trypanosoma cruzi-seropositive dogs (using xenodiagnosis) and their parasite load (quantified by qPCR), and tested the association between both variables and the presence of concomitant endoparasites. A cross-sectional serosurvey conducted in eight rural villages from Pampa del Indio and neighboring municipalities (northeastern Argentina) detected 32 T. cruzi-seropositive dogs out of 217 individuals examined for infection. Both the infectiousness to the vector Triatoma infestans and parasite load of T. cruzi-seropositive dogs examined were heterogeneous. A statistically significant, nine-fold higher mean infectiousness was registered in T. cruzi-seropositive dogs co-infected with Ancylostoma caninum and a trematode than in T. cruzi-seropositive dogs without these infections. The median parasite load of T. cruzi was also significantly higher in dogs co-infected with these helminths. An opposite trend was observed in T. cruzi-seropositive dogs that were serologically positive to Toxoplasma gondii or Neospora caninum relative to dogs seronegative for these parasites. Using multiple logistic regression analysis with random effects, we found a positive and significant association between the infectiousness of T. cruzi-seropositive dogs and co-infections with A. caninum and a trematode. Our results suggest that co-infections may be a modifier of host infectiousness in dogs naturally infected with T. cruzi.
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Affiliation(s)
- G F Enriquez
- Laboratory of Eco-Epidemiology, Faculty of Exact and Natural Sciences, University of Buenos Aires, Argentina; Institute of Ecology, Genetics and Evolution of Buenos Aires (UBA-CONICET), Argentina
| | - G Garbossa
- Laboratory of Clinical and Environmental Parasitology, Faculty of Exact and Natural Sciences, University of Buenos Aires, (IQUIBICEN-CONICET-UBA), Public Health Research Institute, Argentina
| | - N P Macchiaverna
- Laboratory of Eco-Epidemiology, Faculty of Exact and Natural Sciences, University of Buenos Aires, Argentina; Institute of Ecology, Genetics and Evolution of Buenos Aires (UBA-CONICET), Argentina
| | - H D Argibay
- Laboratory of Eco-Epidemiology, Faculty of Exact and Natural Sciences, University of Buenos Aires, Argentina; Institute of Ecology, Genetics and Evolution of Buenos Aires (UBA-CONICET), Argentina
| | - J Bua
- National Institute of Parasitology Dr. M. Fatala Chaben, National Administration of Laboratories and Institutes of Health Dr. C.G. Malbrán, Buenos Aires, Argentina
| | - R E Gürtler
- Laboratory of Eco-Epidemiology, Faculty of Exact and Natural Sciences, University of Buenos Aires, Argentina; Institute of Ecology, Genetics and Evolution of Buenos Aires (UBA-CONICET), Argentina
| | - M V Cardinal
- Laboratory of Eco-Epidemiology, Faculty of Exact and Natural Sciences, University of Buenos Aires, Argentina; Institute of Ecology, Genetics and Evolution of Buenos Aires (UBA-CONICET), Argentina.
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Gjini E, Brito PH. Integrating Antimicrobial Therapy with Host Immunity to Fight Drug-Resistant Infections: Classical vs. Adaptive Treatment. PLoS Comput Biol 2016; 12:e1004857. [PMID: 27078624 PMCID: PMC4831758 DOI: 10.1371/journal.pcbi.1004857] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/09/2016] [Indexed: 12/18/2022] Open
Abstract
Antimicrobial resistance of infectious agents is a growing problem worldwide. To prevent the continuing selection and spread of drug resistance, rational design of antibiotic treatment is needed, and the question of aggressive vs. moderate therapies is currently heatedly debated. Host immunity is an important, but often-overlooked factor in the clearance of drug-resistant infections. In this work, we compare aggressive and moderate antibiotic treatment, accounting for host immunity effects. We use mathematical modelling of within-host infection dynamics to study the interplay between pathogen-dependent host immune responses and antibiotic treatment. We compare classical (fixed dose and duration) and adaptive (coupled to pathogen load) treatment regimes, exploring systematically infection outcomes such as time to clearance, immunopathology, host immunization, and selection of resistant bacteria. Our analysis and simulations uncover effective treatment strategies that promote synergy between the host immune system and the antimicrobial drug in clearing infection. Both in classical and adaptive treatment, we quantify how treatment timing and the strength of the immune response determine the success of moderate therapies. We explain key parameters and dimensions, where an adaptive regime differs from classical treatment, bringing new insight into the ongoing debate of resistance management. Emphasizing the sensitivity of treatment outcomes to the balance between external antibiotic intervention and endogenous natural defenses, our study calls for more empirical attention to host immunity processes.
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Affiliation(s)
- Erida Gjini
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- * E-mail:
| | - Patricia H. Brito
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Nova Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
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Fernandes JV, DE Medeiros Fernandes TAA, DE Azevedo JCV, Cobucci RNO, DE Carvalho MGF, Andrade VS, DE Araújo JMG. Link between chronic inflammation and human papillomavirus-induced carcinogenesis (Review). Oncol Lett 2015; 9:1015-1026. [PMID: 25663851 PMCID: PMC4315066 DOI: 10.3892/ol.2015.2884] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 10/02/2014] [Indexed: 02/06/2023] Open
Abstract
Inflammation is a defense strategy against invading agents and harmful molecules that is activated immediately following a stimulus, and involves the release of cytokines and chemokines, which activate the innate immune response. These mediators act together to increase blood flow and vascular permeability, facilitating recruitment of effector cells to the site of injury. Following resolution of the injury and removal of the stimulus, inflammation is disabled, but if the stimulus persists, inflammation becomes chronic and is strongly associated with cancer. This is likely to be due to the fact that the inflammation leads to a wound that does not heal, requiring a constant renewal of cells, which increases the risk of neoplastic transformation. Debris from phagocytosis, including the reactive species of oxygen and nitrogen that cause damage to DNA already damaged by the leukotrienes and prostaglandins, has an impact on inflammation and various carcinogenic routes. There is an association between chronic inflammation, persistent infection and cancer, where oncogenic action is mediated by autocrine and paracrine signals, causing changes in somatic cells under the influence of the microbial genome or of epigenetic factors. Among the infectious agents associated with cancer, certain genotypes of human papillomavirus (HPV) stand out. HPV is responsible for virtually all cases of cervical cancer and a lower proportion of cancers of the vagina, vulva, anus, penis and a number of extragenital cancers. In the present review, recent advances in the mechanisms involved in the inflammatory response are presented with their participation in the process of carcinogenesis, emphasizing the role of chronic inflammation in the development of HPV-induced cervical cancer.
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Affiliation(s)
- José Veríssimo Fernandes
- Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal 59072-970, Brazil
| | | | | | | | | | - Vania Sousa Andrade
- Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal 59072-970, Brazil
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Aoshiba K, Tsuji T, Itoh M, Yamaguchi K, Nakamura H. An evolutionary medicine approach to understanding factors that contribute to chronic obstructive pulmonary disease. Respiration 2015; 89:243-52. [PMID: 25677028 DOI: 10.1159/000369861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 11/04/2014] [Indexed: 02/05/2023] Open
Abstract
Although many studies have been published on the causes and mechanisms of chronic obstructive pulmonary disease (COPD), the reason for the existence of COPD and the reasons why COPD develops in humans have hardly been studied. Evolutionary medical approaches are required to explain not only the proximate factors, such as the causes and mechanisms of a disease, but the ultimate (evolutionary) factors as well, such as why the disease is present and why the disease develops in humans. According to the concepts of evolutionary medicine, disease susceptibility is acquired as a result of natural selection during the evolutionary process of traits linked to the genes involved in disease susceptibility. In this paper, we discuss the following six reasons why COPD develops in humans based on current evolutionary medical theories: (1) evolutionary constraints; (2) mismatch between environmental changes and evolution; (3) co-evolution with pathogenic microorganisms; (4) life history trade-off; (5) defenses and their costs, and (6) reproductive success at the expense of health. Our perspective pursues evolutionary answers to the fundamental question, 'Why are humans susceptible to this common disease, COPD, despite their long evolutionary history?' We believe that the perspectives offered by evolutionary medicine are essential for researchers to better understand the significance of their work.
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Affiliation(s)
- Kazutetsu Aoshiba
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, Inashiki, Japan
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Belloni V, Sorci G, Paccagnini E, Guerreiro R, Bellenger J, Faivre B. Disrupting immune regulation incurs transient costs in male reproductive function. PLoS One 2014; 9:e84606. [PMID: 24400103 PMCID: PMC3882243 DOI: 10.1371/journal.pone.0084606] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 11/15/2013] [Indexed: 11/19/2022] Open
Abstract
Background Immune protection against pathogenic organisms has been shown to incur costs. Previous studies investigating the cost of immunity have mostly focused on the metabolic requirements of immune maintenance and activation. In addition to these metabolic costs, the immune system can induce damage to the host if the immune response is mis-targeted or over-expressed. Given its non-specific nature, an over-expressed inflammatory response is often associated with substantial damage for the host. Here, we investigated the cost of an over-expressed inflammatory response in the reproductive function of male mice. Methodology/Principal Findings We experimentally blocked the receptors of an anti-inflammatory cytokine (IL-10) in male mice exposed to a mild inflammatory challenge, with each treatment having an appropriate control group. The experiment was conducted on two age classes, young (3 month old) and old (15 month old) mice, to assess any age-related difference in the cost of a disrupted immune regulation. We found that the concomitant exposure to an inflammatory insult and the blockade of IL-10 induced a reduction in testis mass, compared to the three other groups. The frequency of abnormal sperm morphology was also higher in the group of mice exposed to the inflammatory challenge but did not depend on the blockade of the IL-10. Conclusions Our results provide evidence that immune regulation confers protection against the risk of inflammation-induced infertility during infection. They also suggest that disruption of the effectors involved in the regulation of the inflammatory response can have serious fitness consequences even under mild inflammatory insult and benign environmental conditions.
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Affiliation(s)
- Virginia Belloni
- Biogéosciences, CNRS UMR 6282, Université de Bourgogne, Dijon, France
- Department Tropical Medicine, University of Tulane, New Orleans, Louisiana, United States of America
- * E-mail:
| | - Gabriele Sorci
- Biogéosciences, CNRS UMR 6282, Université de Bourgogne, Dijon, France
| | | | - Romain Guerreiro
- Biogéosciences, CNRS UMR 6282, Université de Bourgogne, Dijon, France
| | - Jérôme Bellenger
- Lipides Nutrition Cancer, INSERM UMR 866, Université de Bourgogne, Dijon, France
| | - Bruno Faivre
- Biogéosciences, CNRS UMR 6282, Université de Bourgogne, Dijon, France
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Meitern R, Sild E, Lind MA, Männiste M, Sepp T, Karu U, Hõrak P. Effects of Endotoxin and Psychological Stress on Redox Physiology, Immunity and Feather Corticosterone in Greenfinches. PLoS One 2013; 8:e67545. [PMID: 23805316 PMCID: PMC3689720 DOI: 10.1371/journal.pone.0067545] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 05/20/2013] [Indexed: 12/24/2022] Open
Abstract
Assessment of costs accompanying activation of immune system and related neuroendocrine pathways is essential for understanding the selective forces operating on these systems. Here we attempted to detect such costs in terms of disruption to redox balance and interference between different immune system components in captive wild-caught greenfinches (Carduelis chloris). Study birds were subjected to an endotoxin-induced inflammatory challenge and temporary exposure to a psychological stressor (an image of a predator) in a 2*2 factorial experiment. Injection of bacterial endotoxin resulted in up-regulation of two markers of antioxidant protection – erythrocyte glutathione, and plasma oxygen radical absorbance (OXY). These findings suggest that inflammatory responses alter redox homeostasis. However, no effect on markers of oxidative damage to proteins or DNA in erythrocytes could be detected. We found no evidence that the endotoxin injection interfered with antibody production against Brucella abortus antigen or the intensity of chronic coccidiosis. The hypothesis of within-immune system trade-offs as a cost of immunity was thus not supported in our model system. We showed for the first time that administration of endotoxin can reduce the level of corticosterone deposited into feathers. This finding suggests a down-regulation of the corticosterone secretion cascade due to an endotoxin-induced immune response, a phenomenon that has not been reported previously. Exposure to the predator image did not affect any of the measured physiological parameters.
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Affiliation(s)
- Richard Meitern
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Tartu, Estonia
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Webb SD, Keeling MJ, Boots M. The role of spatial population structure on the evolution of parasites with acquired immunity and demography. J Theor Biol 2013; 324:21-31. [DOI: 10.1016/j.jtbi.2013.01.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 01/18/2013] [Accepted: 01/22/2013] [Indexed: 12/29/2022]
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Russo J, Madec L. Linking immune patterns and life history shows two distinct defense strategies in land snails (gastropoda, pulmonata). Physiol Biochem Zool 2013; 86:193-204. [PMID: 23434779 DOI: 10.1086/669482] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Life history integration of the defense response was investigated at intra- and interspecific levels in land snails of the family Helicidae. Two hypotheses were tested: (i) fitness consequences of defense responses are closely related to life history traits such as size at maturity and life span; (ii) different pathways of the immune response based on "nonspecific" versus "specific" responses may reflect different defense options. Relevant immune responses to a challenge with E. coli were measured using the following variables: blood cell density, cellular or plasma antibacterial activity via reactive oxygen species (ROS) level, and bacterial growth inhibition. The results revealed that the largest snails did not exhibit the strongest immune response. Instead, body mass influenced the type of response in determining the appropriate strategy. Snails with a higher body mass at maturity had more robust plasma immune responses than snails with a lower mass, which had greater cell-mediated immune responses with a higher hemocyte density. In addition, ROS appeared also to be a stress mediator as attested by differences between sites and generations for the same species.
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Affiliation(s)
- Jacqueline Russo
- Université de Rennes 1, Unité Mixte de Recherche 6553 ECOBIO, Campus de Beaulieu, Rennes Cedex, France.
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Ashley NT, Weil ZM, Nelson RJ. Inflammation: Mechanisms, Costs, and Natural Variation. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2012. [DOI: 10.1146/annurev-ecolsys-040212-092530] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Noah T. Ashley
- Department of Biology, Western Kentucky University, Bowling Green, Kentucky 42101;
| | - Zachary M. Weil
- Department of Neuroscience, Wexner College of Medicine, Ohio State University, Columbus, Ohio 43210; ,
| | - Randy J. Nelson
- Department of Neuroscience, Wexner College of Medicine, Ohio State University, Columbus, Ohio 43210; ,
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Coinfection of Schistosoma (Trematoda) with bacteria, protozoa and helminths. ADVANCES IN PARASITOLOGY 2012; 77:1-85. [PMID: 22137582 DOI: 10.1016/b978-0-12-391429-3.00005-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This review examines coinfection of selected species of Schistosoma with bacteria, protozoa and helminths and focuses on the effects of the coinfection on the hosts. The review is based mainly on tables that contain the salient information on the coinfecting organisms in vertebrate hosts. Further explanation and clarification of the tables are given in the text. A table is also provided that gives synoptic information on the 37 species in the 19 genera considered in this review. Coinfection studies with Schistosoma species and the other organisms were considered in six tables plus the accompanying text. Considerations of the Schistosoma interactions with another species of organism include studies on coinfection with Plasmodium, with protozoa other than Plasmodium; with Salmonella, with bacteria other than Salmonella; and with Fasciola, with helminths other than Fasciola. Numerous factors were found to influence the effects of coinfection on the vertebrate host, including organisms and hosts used in the studies, order and time interval between the first and the second infection, studies on natural versus experimental hosts, dosage of the infectious agents, strains and pedigrees of the parasites, age of hosts at time of exposure to the infectious agents and age of hosts at the time of necropsy. Overall, a prior infection with Schistosoma, particularly a patent infection, often has an effect on the subsequent infection by a protozoan, bacterium or other helminth. In relatively few cases, a prior infection with Schistosoma decreased the severity of the subsequent infection as with Helicobacter pylori, Fasciola hepatica, Echinostoma or Plasmodium, the latter only exhibiting this behaviour when coinfected with Schistosoma haematobium. More often, however, a prior infection with Schistosoma increased the severity of the second infection as with Leishmania, Toxoplasma gondii, Entamoeba histolytica, Staphylococcus aureus or Salmonella. In some of these coinfection studies, the increased severity of the subsequent infection was associated with a specific, prolonged form of the disease in humans, which has implications for patient treatment and recovery. Additional research is needed, particularly on Schistosoma coinfections which currently have a small body of research and are current problems in human populations. Examples of such Schistosoma interactions include the genera of Mycobacteria, Leishmania, Staphylococcus, Necator and Strongyloides. Hopefully, future studies will elucidate valuable new information on the interesting subject of coinfection of Schistosoma with other organisms.
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Hellard E, Pontier D, Sauvage F, Poulet H, Fouchet D. True versus false parasite interactions: a robust method to take risk factors into account and its application to feline viruses. PLoS One 2012; 7:e29618. [PMID: 22235312 PMCID: PMC3250451 DOI: 10.1371/journal.pone.0029618] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 12/01/2011] [Indexed: 01/25/2023] Open
Abstract
Background Multiple infections are common in natural host populations and interspecific parasite interactions are therefore likely within a host individual. As they may seriously impact the circulation of certain parasites and the emergence and management of infectious diseases, their study is essential. In the field, detecting parasite interactions is rendered difficult by the fact that a large number of co-infected individuals may also be observed when two parasites share common risk factors. To correct for these “false interactions”, methods accounting for parasite risk factors must be used. Methodology/Principal Findings In the present paper we propose such a method for presence-absence data (i.e., serology). Our method enables the calculation of the expected frequencies of single and double infected individuals under the independence hypothesis, before comparing them to the observed ones using the chi-square statistic. The method is termed “the corrected chi-square.” Its robustness was compared to a pre-existing method based on logistic regression and the corrected chi-square proved to be much more robust for small sample sizes. Since the logistic regression approach is easier to implement, we propose as a rule of thumb to use the latter when the ratio between the sample size and the number of parameters is above ten. Applied to serological data for four viruses infecting cats, the approach revealed pairwise interactions between the Feline Herpesvirus, Parvovirus and Calicivirus, whereas the infection by FIV, the feline equivalent of HIV, did not modify the risk of infection by any of these viruses. Conclusions/Significance This work therefore points out possible interactions that can be further investigated in experimental conditions and, by providing a user-friendly R program and a tutorial example, offers new opportunities for animal and human epidemiologists to detect interactions of interest in the field, a crucial step in the challenge of multiple infections.
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Shrestha S. Influence of host genetic and ecological factors in complex concomitant infections - relevance to sexually transmitted infections. J Reprod Immunol 2011; 92:27-32. [PMID: 22019002 DOI: 10.1016/j.jri.2011.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/06/2011] [Accepted: 09/10/2011] [Indexed: 12/16/2022]
Abstract
While there is evidence that host genetics plays a role in susceptibility and subsequent sequelae of sexually transmitted infections (STIs), association findings have been inconsistent in deciphering the causal genes or biological pathways involved in the different life cycle and pathogenesis of infectious microbes. The lack of replication and validation studies from genome-wide association studies in general and specifically with infectious diseases, including STIs, is a continuing problem that limits the utility of these studies. Cohort heterogeneity, sample size, and confounding by population stratification due to differences in genetic polymorphisms in different ethnic groups are the usual explanations. However, in the context of genetic epidemiology studies of infectious disease, apart from the involvement of at least two genomes (the host and the pathogen), local environmental factors in the host shared by concomitant infections are often not examined. Different infectious microbes contribute to the shared local microenvironment, and the immune response can be favorable or unfavorable to different microbes individually and concomitantly at various levels. The balance of each infection relative to the other concomitant infections is a major confounder that has been under-studied. Thus, host genetic studies examining only one pathogen can yield inconsistent associations. This warrants a new paradigm that uses an ecological network-based study design and analysis tools. Defining the role of genetics in concomitant infection is likely to provide insight into pathogenic and protective mechanisms and to identify interdependent molecular targets for prophylactic and therapeutic interventions to multiple co-infections.
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Affiliation(s)
- Sadeep Shrestha
- Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL 35294-0022, USA.
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Axtner J, Sommer S. Heligmosomoides polygyrus infection is associated with lower MHC class II gene expression in Apodemus flavicollis: indication for immune suppression? INFECTION GENETICS AND EVOLUTION 2011; 11:2063-71. [PMID: 21983561 DOI: 10.1016/j.meegid.2011.09.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 09/22/2011] [Accepted: 09/22/2011] [Indexed: 01/16/2023]
Abstract
Due to their key role in recognizing foreign antigens and triggering the subsequent immune response the genes of the major histocompatibility complex (MHC) provide a potential target for parasites to attack in order to evade detection and expulsion from the host. A diminished MHC gene expression results in less activated T cells and might serve as a gateway for pathogens and parasites. Some parasites are suspected to be immune suppressors and promote co-infections of other parasites even in other parts of the body. In our study we found indications that the gut dwelling nematode Heligmosomoides polygyrus might exert a systemic immunosuppressive effect in yellow-necked mice (Apodemus flavicollis). The amount of hepatic MHC class II DRB gene RNA transcripts in infected mice was negatively associated with infection intensity with H. polygyrus. The hepatic expression of immunosuppressive cytokines, such as transforming growth factor β and interleukin 10 was not associated with H. polygyrus infection. We did not find direct positive associations of H. polygyrus with other helminth species. But the prevalence and infection intensity of the nematodes Syphacia stroma and Trichuris muris were higher in multiple infected individuals. Furthermore, our data indicated antagonistic effects in the helminth community of A. flavicollis as cestode infection correlated negatively with H. polygyrus and helminth species richness. Our study shows that expression analyses of immune relevant genes can also be performed in wildlife, opening new aspects and possibilities for future ecological and evolutionary research.
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Affiliation(s)
- Jan Axtner
- Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str 15, 10315 Berlin, Germany
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Bordes F, Morand S. The impact of multiple infections on wild animal hosts: a review. Infect Ecol Epidemiol 2011; 1:IEE-1-7346. [PMID: 22957114 PMCID: PMC3426331 DOI: 10.3402/iee.v1i0.7346] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 08/11/2011] [Accepted: 08/25/2011] [Indexed: 12/23/2022] Open
Abstract
Field parasitological studies consistently demonstrate the reality of polyparasitism in natural systems. However, only recently, studies from ecological and evolutionary fields have emphasised a broad spectrum of potential multiple infections-related impacts. The main goal of our review is to reunify the different approaches on the impacts of polyparasitism, not only from laboratory or human medical studies but also from field or theoretical studies. We put forward that ecological and epidemiological determinants to explain the level of polyparasitism, which regularly affects not only host body condition, survival or reproduction but also host metabolism, genetics or immune investment. Despite inherent limitations of all these studies, multiple infections should be considered more systematically in wildlife to better appreciate the importance of parasite diversity in wildlife, cumulative effects of parasitism on the ecology and evolution of their hosts.
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Affiliation(s)
- Frédéric Bordes
- Institut des Sciences de l'Evolution, CNRS-UM2, CC65, Université de Montpellier, Montpellier, France
| | - Serge Morand
- Institut des Sciences de l'Evolution, CNRS-UM2, CC65, Université de Montpellier, Montpellier, France
- UR22 AGIRs, CIRAD, Campus International de Baillarguet, 34398, Montpellier, France
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Gibson AK, Raverty S, Lambourn DM, Huggins J, Magargal SL, Grigg ME. Polyparasitism is associated with increased disease severity in Toxoplasma gondii-infected marine sentinel species. PLoS Negl Trop Dis 2011; 5:e1142. [PMID: 21629726 PMCID: PMC3101184 DOI: 10.1371/journal.pntd.0001142] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 03/07/2011] [Indexed: 11/30/2022] Open
Abstract
In 1995, one of the largest outbreaks of human toxoplasmosis occurred in the Pacific Northwest region of North America. Genetic typing identified a novel Toxoplasma gondii strain linked to the outbreak, in which a wide spectrum of human disease was observed. For this globally-distributed, water-borne zoonosis, strain type is one variable influencing disease, but the inability of strain type to consistently explain variations in disease severity suggests that parasite genotype alone does not determine the outcome of infection. We investigated polyparasitism (infection with multiple parasite species) as a modulator of disease severity by examining the association of concomitant infection of T. gondii and the related parasite Sarcocystis neurona with protozoal disease in wild marine mammals from the Pacific Northwest. These hosts ostensibly serve as sentinels for the detection of terrestrial parasites implicated in water-borne epidemics of humans and wildlife in this endemic region. Marine mammals (151 stranded and 10 healthy individuals) sampled over 6 years were assessed for protozoal infection using multi-locus PCR-DNA sequencing directly from host tissues. Genetic analyses uncovered a high prevalence and diversity of protozoa, with 147/161 (91%) of our sampled population infected. From 2004 to 2009, the relative frequency of S. neurona infections increased dramatically, surpassing that of T. gondii. The majority of T. gondii infections were by genotypes bearing Type I lineage alleles, though strain genotype was not associated with disease severity. Significantly, polyparasitism with S. neurona and T. gondii was common (42%) and was associated with higher mortality and more severe protozoal encephalitis. Our finding of widespread polyparasitism among marine mammals indicates pervasive contamination of waterways by zoonotic agents. Furthermore, the significant association of concomitant infection with mortality and protozoal encephalitis identifies polyparasitism as an important factor contributing to disease severity in marine mammals. Severity of toxoplasmosis, a water-borne zoonosis, varies widely from chronic and benign to acutely fatal. Here, we investigate polyparasitism (infection with multiple parasite species) as one factor governing the spectrum of disease in Toxoplasma gondii infections. This study utilized wild marine mammals as sentinels to detect contamination of waterways by T. gondii and a similar protozoan, Sarcocystis neurona, which have been linked to water-borne outbreaks in humans and wildlife along North America's Pacific Coast. Using genetic tools, we found high rates of protozoal infection, predominantly concomitant infections, in animals inhabiting major waterways of the Pacific Northwest. These dual infections of T. gondii and S. neurona were more frequently associated with mortality and protozoal encephalitis than single infections, indicating a role for polyparasitism in disease severity. Finally, rare T. gondii genotypes linked to a major human outbreak in the Pacific Northwest were abundant in marine mammals of the region, emphasizing wildlife as relevant sentinels for evaluation of human health risks. Our data implicate polyparasitism as a critical factor associated with the severity of protozoal disease. We also identify the need for vigilant surveillance of public waterways to prevent fecal contamination recurrently threatening human and wildlife health along the Pacific coast.
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Affiliation(s)
- Amanda K. Gibson
- Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, United States of America
| | - Stephen Raverty
- Animal Health Centre, Ministry of Agriculture and Food, Abbotsford, British Columbia, Canada
- Marine Mammal Research Unit, Fisheries Centre, Aquatic Ecosystems Research Laboratory (AERL), University of British Columbia, Vancouver, British Columbia, Canada
| | - Dyanna M. Lambourn
- Washington Department of Fish and Wildlife, Lakewood, Washington, United States of America
| | - Jessica Huggins
- Cascadia Research Collective, Olympia, Washington, United States of America
| | - Spencer L. Magargal
- Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, United States of America
| | - Michael E. Grigg
- Laboratory of Parasitic Diseases, National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, Maryland, United States of America
- * E-mail:
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27
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Ardia DR, Parmentier HK, Vogel LA. The role of constraints and limitation in driving individual variation in immune response. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2010.01759.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Daniel R. Ardia
- Department of Biology, Franklin & Marshall College, Lancaster, Pennsylvania 17604, USA
| | - Henk K. Parmentier
- Adaptation Physiology Group, Department of Animal Sciences, Wageningen Institute of Animal Sciences, Marijkeweg 40, 6709 PG Wageningen, The Netherlands
| | - Laura A. Vogel
- School of Biological Sciences, Illinois State University, Normal, Illinois 61790, USA
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Hawley DM, Altizer SM. Disease ecology meets ecological immunology: understanding the links between organismal immunity and infection dynamics in natural populations. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2010.01753.x] [Citation(s) in RCA: 259] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Dana M. Hawley
- Department of Biology, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Sonia M. Altizer
- Odum School of Ecology, University of Georgia, Athens, Georgia 30602, USA
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Daschner A, Cuéllar C. The hidden sense of symptoms: urticaria can be beneficial. Med Hypotheses 2010; 75:623-6. [PMID: 20729003 DOI: 10.1016/j.mehy.2010.07.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 07/27/2010] [Accepted: 07/30/2010] [Indexed: 10/19/2022]
Abstract
Evolutionary Medicine can be useful when analysing the origin of disease and symptoms. Acute urticaria or anaphylaxis is bothersome and potentially life-threatening. We analyse this symptom-complex in the context of Gastro-allergic Anisakiasis (GAA), where the human is an incidental host for the cosmopolitan fish-nematode Anisakis simplex (A. simplex). The immunological response against this nematode resembles that against other helminths, but overt expression of allergic symptoms is by far more frequent in GAA. This could be due to the missing co-evolutionary relationship between host and parasite. Features of acute gastric parasitism with and without overt allergic type 1 hypersensitivity symptoms are compared with the abdominal complications in intestinal Anisakiasis, where clinically visible IgE mediated symptoms are missing. In GAA, parasite induced chronic abdominal complications are missing. We postulate that urticaria in GAA can be considered the price for rapidly expelling the live larva of A. simplex in those subjects whose evolutionary history made them more resistant to other helminth parasites. Further, urticaria is explained as a possibly exaggerated immunopathological feature in this special type of acute parasitism, where sensitized mast-cells are not only present in the skin, but also in the gastro-intestinal mucosa. This evolutionary analysis of clinical observations is the first known report that addresses the possible beneficial feature of hypersensitivity type 1 response with overt allergic urticaria-anaphylaxis in GAA and confers an evolutionary based sense to the acute IgE-mediated reaction.
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Affiliation(s)
- Alvaro Daschner
- Servicio de Alergia, Hospital Universitario La Princesa, Madrid, Spain.
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30
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Martin LB, Hopkins WA, Mydlarz LD, Rohr JR. The effects of anthropogenic global changes on immune functions and disease resistance. Ann N Y Acad Sci 2010; 1195:129-48. [DOI: 10.1111/j.1749-6632.2010.05454.x] [Citation(s) in RCA: 171] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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31
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Anti-retinal autoantibodies in experimental ocular and systemic toxoplasmosis. Graefes Arch Clin Exp Ophthalmol 2009; 248:573-84. [PMID: 19956968 DOI: 10.1007/s00417-009-1242-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2009] [Revised: 10/25/2009] [Accepted: 11/02/2009] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Patients with ocular toxoplasmosis (OT) develop autoreactivity to several retinal antigens, including retinal S-antigen. By establishing an experimental rabbit model of systemic and of primary and secondary ocular toxoplasmosis, we wished to investigate the onset and development of humoral response to retinal S-antigen. METHODS Of twelve infection-naïve rabbits, six were left untreated, and the other six were infected subcutaneously with 5,000 tachyzoites of the highly virulent, non-cyst-forming BK-strain of Toxoplasma gondii. Three months later, the left eye of each animal was infected transvitreally with 5,000 tachyzoites of the same strain. The right eye of each rabbit served as an uninfected control. Blood and aqueous humor were collected prior to infection, and up to 90 days thereafter. Using the ELISA technique, all samples were analyzed in parallel for total IgG, and antibodies against toxoplasmic, bovine retinal S-antigen and peptide 35 from human S-antigen. RESULTS In infection-naïve rabbits Toxoplasma-specific antibodies were detected 10 to 15 days after systemic and ocular infection. Serum antibodies against retinal S-antigen and peptide 35 were not detected in response to systemic Toxoplasma infection. After ocular challenge, aqueous-humour levels of antibodies against retinal S-antigen and peptide 35 in the infected eye began to rise 10 to 15 days later in infection-naïve, but not in infection-immunized animals. During the early post-infection period, the concentrations of anti-retinal antibodies in the infected eye correlated with the severity of inflammatory tissue destruction, but returned to baseline later even though the inflammatory response persisted. In the uninfected partner eye, concentrations of anti-retinal and toxoplasmic antibodies did not correlate with each other. CONCLUSION Our data afford no evidence of similarities between toxoplasmic and retinal antigens, nor of infection-induced humoral autoimmunity. They indicate rather that retinal autoantigens are liberated in the context of inflammatory tissue destruction due to ocular toxoplasmosis.
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32
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Abstract
If immune functions confer obvious benefits to hosts, life-history theory assumes that they also induce costs, leading to trade-offs between immunity and other fitness components. However, whether substantial fitness costs are associated with immune systems in the wild is debatable, as numerous factors may influence the costs and benefits associated with immune activation. Here, we explore the survival cost of immune deployment in postfledging birds. We injected Eurasian collared dove nestlings (Streptopelia decaocto) with antigens from Escherichia coli, and examined whether this immune challenge affected survival after fledging. To assess survival, birds were fitted with radiotags and the fate of each individual was monitored regularly. Our results show that mimicking a bacterial infection in nestlings lowered their survival prospects after fledging, in comparison to controls. The main identified cause of mortality (by examination of dead birds) was presumed to be predation. This study provides experimental evidence that immune activation may entail dramatic survival costs in a free-ranging vertebrate, and emphasizes the potential role that environmental factors such as predation may play in this interaction.
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Affiliation(s)
- Cyril Eraud
- Office National de la Chasse et de la Faune Sauvage. Direction des Etudes et de la Recherche. CNERA Avifaune migratrice. Réserve de Chizé, Carrefour de la Canauderie.79360 Villiers-en-Bois, France.
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33
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Helminth species richness in wild wood mice, Apodemus sylvaticus, is enhanced by the presence of the intestinal nematode Heligmosomoides polygyrus. Parasitology 2009; 136:793-804. [PMID: 19486546 DOI: 10.1017/s0031182009006039] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We analysed 3 independently collected datasets of fully censused helminth burdens in wood mice, Apodemus sylvaticus, testing the a priori hypothesis of Behnke et al. (2005) that the presence of the intestinal nematode Heligmosomoides polygyrus predisposes wood mice to carrying other species of helminths. In Portugal, mice carrying H. polygyrus showed a higher prevalence of other helminths but the magnitude of the effect was seasonal. In Egham, mice with H. polygyrus showed a higher prevalence of other helminth species, not confounded by other factors. In Malham Tarn, mice carrying H. polygyrus were more likely to be infected with other species, but only among older mice. Allowing for other factors, heavy residual H. polygyrus infections carried more species of other helminths in both the Portugal and Egham data; species richness in Malham was too low to conduct a similar analysis, but as H. polygyrus worm burdens increased, so the prevalence of other helminths also increased. Our results support those of Behnke et al. (2005), providing firm evidence that at the level of species richness a highly predictable element of co-infections in wood mice has now been defined: infection with H. polygyrus has detectable consequences for the susceptibility of wood mice to other intestinal helminth species.
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34
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Oliver MK, Telfer S, Piertney SB. Major histocompatibility complex (MHC) heterozygote superiority to natural multi-parasite infections in the water vole (Arvicola terrestris). Proc Biol Sci 2009; 276:1119-28. [PMID: 19129114 DOI: 10.1098/rspb.2008.1525] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The fundamental role of the major histocompatibility complex (MHC) in immune recognition has led to a general consensus that the characteristically high levels of functional polymorphism at MHC genes is maintained by balancing selection operating through host-parasite coevolution. However, the actual mechanism by which selection operates is unclear. Two hypotheses have been proposed: overdominance (or heterozygote superiority) and negative frequency-dependent selection. Evidence for these hypotheses was evaluated by examining MHC-parasite relationships in an island population of water voles (Arvicola terrestris). Generalized linear mixed models were used to examine whether individual variation at an MHC class II DRB locus explained variation in the individual burdens of five different parasites. MHC genotype explained a significant amount of variation in the burden of gamasid mites, fleas (Megabothris walkeri) and nymphs of sheep ticks (Ixodes ricinus). Additionally, MHC heterozygotes were simultaneously co-infected by fewer parasite types than homozygotes. In each case where an MHC-dependent effect on parasite burden was resolved, the heterozygote genotype was associated with fewer parasites, and the heterozygote outperformed each homozygote in two of three cases, suggesting an overall superiority against parasitism for MHC heterozygote genotypes. This is the first demonstration of MHC heterozygote superiority against multiple parasites in a natural population, a mechanism that could help maintain high levels of functional MHC genetic diversity in natural populations.
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Affiliation(s)
- M K Oliver
- Institute of Biological and Environmental Sciences, University of Aberdeen, Zoology Building, Aberdeen AB24 2TZ, UK.
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35
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Alizon S, van Baalen M. Acute or chronic? Within-host models with immune dynamics, infection outcome, and parasite evolution. Am Nat 2009; 172:E244-56. [PMID: 18999939 DOI: 10.1086/592404] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
There is ample theoretical and experimental evidence that virulence evolution depends on the immune response of the host. In this article, we review a number of recent studies that attempt to explicitly incorporate the dynamics of the immune system (instead of merely representing it by a single black box parameter) in models for the evolution of parasite virulence. A striking observation is that the type of infection (acute or chronic) is invariably considered to be a constraint that model assumptions have to satisfy rather than as a potential outcome of the interaction of the parasite with its host's immune system. We argue that avoiding making assumptions about the type of infection will lead to a better understanding of infectious diseases, even though a number of fundamental and technical problems remain. Dynamical modeling of the immune system opens a wide range of perspectives: for understanding how the immune system eradicates a parasite (which it does for most pathogens but not for all, HIV being a notorious example of a virus that is not completely eliminated), for studying multiple infections through concomitant immunity, for understanding the emergence and evolution of the immune system in animals, and for evolutionary epidemiology in general (e.g., predicting evolutionary consequences of new therapies and public health policies). We conclude by discussing new approaches based on embedded (or nested) models and identify future perspectives for the modeling of infectious diseases.
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Affiliation(s)
- Samuel Alizon
- Ecole Normale Supérieure, Unité Mixte de Recherche 7625 Fonctionnement et Evolution des Systèmes Ecologiques, Paris F-75005, France.
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36
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Arriero E. Rearing environment effects on immune defence in blue tit Cyanistes caeruleus nestlings. Oecologia 2009; 159:697-704. [DOI: 10.1007/s00442-008-1253-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 11/26/2008] [Indexed: 11/24/2022]
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37
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Brown SP, Fredrik Inglis R, Taddei F. Evolutionary ecology of microbial wars: within-host competition and (incidental) virulence. Evol Appl 2009; 2:32-9. [PMID: 25567845 PMCID: PMC3352407 DOI: 10.1111/j.1752-4571.2008.00059.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 11/27/2008] [Indexed: 11/29/2022] Open
Abstract
Invading an occupied niche is a formidable ecological challenge, and one of particular human importance in the context of food-borne microbial pathogens. We discuss distinct categories of invader-triggered environmental change that facilitate invasion by emptying their niche of competitors. Evidence is reviewed that gut bacteria use such strategies to manipulate their environment (via bacteriocins, temperate phage viruses or immuno-manipulation) at the expense of their competitors are reviewed. The possible virulence implications of microbial warfare among multiple co-infecting strains are diverse. Killing competitors can reduce virulence by reducing overall microbial densities, or increase virulence if for example the allelopathic mechanism involves immuno-manipulation. Finally, we place microbial anti-competitor strategies in a social evolution framework, highlighting how costly anti-competitor strategies can be understood as examples of microbial spite. We conclude by discussing other invasive species that have also developed such proactive strategies of invasion.
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Affiliation(s)
- Sam P Brown
- Department of Zoology, University of Oxford South Parks Road, Oxford, UK
| | - R Fredrik Inglis
- Department of Zoology, University of Oxford South Parks Road, Oxford, UK
| | - François Taddei
- University of Paris, Faculty of Medicine INSERM, U571, Paris, France
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38
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Gallizzi K, Alloitteau O, Harrang E, Richner H. Fleas, parental care, and transgenerational effects on tick load in the great tit. Behav Ecol 2008. [DOI: 10.1093/beheco/arn083] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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39
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Parasite interactions in natural populations: insights from longitudinal data. Parasitology 2008; 135:767-81. [PMID: 18474121 DOI: 10.1017/s0031182008000395] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The physiological and immunological state of an animal can be influenced by current infections and infection history. Consequently, both ongoing and previous infections can affect host susceptibility to another parasite, the biology of the subsequent infection (e.g. infection length) and the impact of infection on host morbidity (pathology). In natural populations, most animals will be infected by a succession of different parasites throughout the course of their lives, with probably frequent concomitant infections. The relative timing of different infections experienced by a host (i.e. the sequence of infection events), and the effects on factors such as host susceptibility and host survival, can only be derived from longitudinal data on individual hosts. Here we review some of the evidence for the impact of co-infection on host susceptibility, infection biology and pathology focusing on insights obtained from both longitudinal studies in humans and experiments that explicitly consider the sequence of infection. We then consider the challenges posed by longitudinal infection data collected from natural populations of animals. We illustrate their usefulness using our data of microparasite infections associated with field vole (Microtus agrestis) populations to examine impacts on susceptibility and infection length. Our primary aim is to describe an analytical approach that can be used on such data to identify interactions among the parasites. The preliminary analyses presented here indicate both synergistic and antagonistic interactions between microparasites within this community and emphasise that such interactions could have significant impacts on host-parasite fitness and dynamics.
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40
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Structure in parasite component communities in wild rodents: predictability, stability, associations and interactions .... or pure randomness? Parasitology 2008; 135:751-66. [PMID: 18371244 DOI: 10.1017/s0031182008000334] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Experimental data establish that interactions exist between species of intestinal helminths during concurrent infections in rodents, the strongest effects being mediated through the host's immune responses. Detecting immune-mediated relationships in wild rodent populations has been fraught with problems and published data do not support a major role for interactions in structuring helminth communities. Helminths in wild rodents show predictable patterns of seasonal, host age-dependent and spatial variation in species richness and in abundance of core species. When these are controlled for, patterns of co-infection compatible with synergistic interactions can be demonstrated. At least one of these, the positive relationship between Heligmosomoides polygyrus and species richness of other helminths has been demonstrated in three totally independent data-sets. Collectively, they explain only a small percentage of the variance/deviance in abundance data and at this level are unlikely to play a major role in structuring helminth communities, although they may be important in the more heavily infected wood mice. Current worm burdens underestimate the possibility that earlier interactions through the immune system have taken place, and therefore interactions may have a greater role to play than is immediately evident from current worm burdens. Longitudinal studies are proposed to resolve this issue.
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41
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Abstract
For hundreds of years, the unmanaged Soay sheep population on St Kilda has survived despite enduring presumably deleterious co-infections of helminth, protozoan and arthropod parasites and intermittent periods of starvation. Important parasite taxa in young Soay sheep are strongyles (Trichostrongylus axei, Trichostrongylus vitrinus and Teladorsagia circumcincta), coccidia (11 Eimeria species) and keds (Melophagus ovinus) and in older animals, Teladorsagia circumcincta. In this research, associations between the intensity of different parasite taxa were investigated. Secondly, the intensities of different parasite taxa were tested for associations with variation in host weight, which is itself a determinant of over-winter survival in the host population. In lambs, the intensity of strongyle eggs was positively correlated with that of Nematodirus spp. eggs, while in yearlings and adults strongyle eggs and coccidia oocysts were positively correlated. In lambs and yearlings, of the parasite taxa tested, only strongyle eggs were significantly and negatively associated with host weight. However, in adult hosts, strongyles and coccidia were independently and negatively associated with host weight. These results are consistent with the idea that strongyles and coccidia are exerting independent selection on Soay sheep.
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42
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Graham AL. Ecological rules governing helminth-microparasite coinfection. Proc Natl Acad Sci U S A 2008; 105:566-70. [PMID: 18182496 PMCID: PMC2206576 DOI: 10.1073/pnas.0707221105] [Citation(s) in RCA: 267] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Indexed: 11/18/2022] Open
Abstract
Coinfection of a host by multiple parasite species has important epidemiological and clinical implications. However, the direction and magnitude of effects vary considerably among systems, and, until now, there has been no general framework within which to explain this variation. Community ecology has great potential for application to such problems in biomedicine. Here, metaanalysis of data from 54 experiments on laboratory mice reveals that basic ecological rules govern the outcome of coinfection across a broad spectrum of parasite taxa. Specifically, resource-based ("bottom-up") and predator-based ("top-down") control mechanisms combined to determine microparasite population size in helminth-coinfected hosts. Coinfection imposed bottom-up control (resulting in decreased microparasite density) when a helminth that causes anemia was paired with a microparasite species that requires host red blood cells. At the same time, coinfection impaired top-down control of microparasites by the immune system: the greater the helminth-induced suppression of the inflammatory cytokine interferon (IFN)-gamma, the greater the increase in microparasite density. These results suggest that microparasite population growth will be most explosive when underlying helminths do not impose resource limitations but do strongly modulate IFN-gamma responses. Surprisingly simple rules and an ecological framework within which to analyze biomedical data thus emerge from analysis of this dataset. Through such an interdisciplinary lens, predicting the outcome of coinfection may become tractable.
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Affiliation(s)
- Andrea L Graham
- Institute of Evolution, School of Biological Sciences, University of Edinburgh, King's Buildings, Ashworth Laboratories, Edinburgh EH9 3JT, Scotland.
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43
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Brown SP, Le Chat L, Taddei F. Evolution of virulence: triggering host inflammation allows invading pathogens to exclude competitors. Ecol Lett 2007; 11:44-51. [PMID: 18021245 PMCID: PMC2228394 DOI: 10.1111/j.1461-0248.2007.01125.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Virulence is generally considered to benefit parasites by enhancing resource-transfer from host to pathogen. Here, we offer an alternative framework where virulent immune-provoking behaviours and enhanced immune resistance are joint tactics of invading pathogens to eliminate resident competitors (transferring resources from resident to invading pathogen). The pathogen wins by creating a novel immunological challenge to which it is already adapted. We analyse a general ecological model of 'proactive invasion' where invaders not adapted to a local environment can succeed by changing it to one where they are better adapted than residents. However, the two-trait nature of the 'proactive' strategy (provocation of, and adaptation to environmental change) presents an evolutionary conundrum, as neither trait alone is favoured in a homogenous host population. We show that this conundrum can be resolved by allowing for host heterogeneity. We relate our model to emerging empirical findings on immunological mediation of parasite competition.
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Affiliation(s)
- Sam P Brown
- Section of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA.
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44
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HAWLEY DM, JENNELLE CS, SYDENSTRICKER KV, DHONDT AA. Pathogen resistance and immunocompetence covary with social status in house finches (Carpodacus mexicanus). Funct Ecol 2007. [DOI: 10.1111/j.1365-2435.2007.01254.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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45
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Sitjà-Bobadilla A, Pujalte MJ, Macián MC, Pascual J, Alvarez-Pellitero P, Garay E. Interactions between bacteria and Cryptosporidium molnari in gilthead sea bream (Sparus aurata) under farm and laboratory conditions. Vet Parasitol 2006; 142:248-59. [PMID: 16934406 DOI: 10.1016/j.vetpar.2006.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Revised: 06/30/2006] [Accepted: 07/06/2006] [Indexed: 11/23/2022]
Abstract
The possible interaction of Cryptosporidium molnari and bacteria in gilthead sea bream (Sparus aurata) was studied. Epidemiological data from a pathological survey under farm conditions were analyzed. In addition, parasite and bacteria burdens were studied in experimental models in which naturally and experimentally parasitized fish were challenged with a particular strain of Vibrio harveyi (H57). All the bacteria species present were studied. Under farm conditions, the parasite was more prevalent when mortality or morbidity cases (study C) occurred than in randomly sampled fish (study B). In study C, parasite abundance was significantly higher in bacteria-negative fish, and total bacteria abundance was significantly higher within non-parasitized fish. V. harveyi and V. splendidus were the most prevalent among bacteria carriers in studies B and C, respectively. In study C, among bacteria carriers, most isolates were slightly more prevalent in parasitized than in non-parasitized fish. Two groups (G1, G2) of naturally parasitized fish were inoculated with H57 by intracoelomic injection (ICI) and by oral intubation (OI). H57 was recovered only in G1 inoculated fish, which had a significantly higher basal abundance of total bacteria, and where the only ones with mortalities. In G1, the mortality rate and the prevalence of other V. harveyi strains different from the H57 molecular type were higher in ICI than in OI fish, and the total bacteria abundance was also significantly higher in ICI fish. C. molnari abundance was significantly higher in G1 than in G2, and also in OI than in ICI fish within G1. When H57 was IC inoculated to fish (G3, from the same farm as G2) experimentally infected with C. molnari, H57 was not recovered from any fish. A low mortality was recorded, and only in those fish inoculated with both pathogens. Also in these fish, the prevalence of infection of C. molnari was higher and histopathological damage to the stomach was greater than in fish inoculated only with the parasite. Therefore, the impact of the parasite would be reduced notably when the bacterial burden or the intensity of parasite infection are low (G2, G3).
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Affiliation(s)
- A Sitjà-Bobadilla
- Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Torre de la Sal s/n, 12595 Ribera de Cabanes, Castellón, Spain.
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46
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Craig BH, Pilkington JG, Kruuk LEB, Pemberton JM. Epidemiology of parasitic protozoan infections in Soay sheep (Ovis aries L.) on St Kilda. Parasitology 2006; 134:9-21. [PMID: 16978448 DOI: 10.1017/s0031182006001144] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 06/28/2006] [Accepted: 06/29/2006] [Indexed: 11/07/2022]
Abstract
The feral Soay sheep (Ovis aries L.) population on Hirta, St Kilda, is host to a diverse component parasite community, but previous parasitological studies of the population have only focussed on the metazoan species. This paper reports the first epidemiological study of the protozoan species comprising Cryptosporidium parvum, Giardia duodenalis and 11 species of Eimeria in Soay sheep across 3 years of varying host population density. Prevalence and intensity of almost all species of protozoa significantly decreased with host age, with the exception of E. granulosa, which increased in prevalence with host age. The prevalence of C. parvum appeared to vary positively with host population density but that of G. duodenalis did not vary significantly with density. Most species of Eimeria showed a distinct lag in infection level following the host population crash of 2002, taking up to 2 years to decrease. Mixed Eimeria species intensity and diversity were highest in 2002, a year of low host density. Parasite diversity decreased with host age and was higher in males. There were 5 positive pair-wise associations between protozoa species in terms of prevalence. The results of this study highlight the potential for protozoal infection to shape the evolution of parasite resistance in wild host populations harbouring diverse parasite species.
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Affiliation(s)
- B H Craig
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, Scotland.
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47
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MARTIN II LB, WEIL ZM, KUHLMAN JR, NELSON RJ. Trade-offs within the immune systems of female White-footed Mice, Peromyscus leucopus. Funct Ecol 2006. [DOI: 10.1111/j.1365-2435.2006.01138.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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48
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Craig BH, Pilkington JG, Pemberton JM. Gastrointestinal nematode species burdens and host mortality in a feral sheep population. Parasitology 2006; 133:485-96. [PMID: 16817995 DOI: 10.1017/s0031182006000618] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 04/24/2006] [Accepted: 05/08/2006] [Indexed: 11/05/2022]
Abstract
Every few years a large proportion of the feral sheep on Hirta, St Kilda die due to food shortage. The effects of malnutrition are exacerbated by gastrointestinal nematodes. As found in sheep flocks in mainland Britain, Teladorsagia circumcincta has long been considered the predominant and most pathogenic nematode species in all age classes of Soay sheep. Previous research indicated that intensity of this species showed a negative association with host age and comprised 75% of the entire gastrointestinal burden. Here we present new data that show Trichostrongylus axei and Trichostrongylus vitrinus to be the predominant worm pathogens in young Soay sheep. In the present study, Trichostrongylus spp. burdens declined with host age whereas T. circumcincta actually increased in burden over the first few age classes. Also, male hosts had significantly higher burdens of Trichostrongylus spp. than females, with this genus making up a higher proportion of the strongyle egg producing community in male hosts than female hosts. These new findings raise questions concerning our previous interpretation of the main nematode species contributing to strongyle egg count in the population, and the contrasting infection patterns of these nematode species in unmanaged St Kilda Soay sheep compared with domestic sheep in mainland Britain.
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Affiliation(s)
- B H Craig
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Scotland.
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49
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Quinn GAP, Heymans R, Rondaj F, Shaw C, de Jong-Brink M. Schistosoma mansoni dermaseptin-like peptide: structural and functional characterization. J Parasitol 2006; 91:1340-51. [PMID: 16539015 DOI: 10.1645/ge-540r.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Analysis of the Schistosoma mansoni peptidome for immunomodulatory molecules by solvent extraction and reverse-phase HPLC revealed a 27-amino-acid residue peptide from an extract of cercariae. Using matrix-assisted, laser desorption-ionization, time-of-flight mass spectrometry, the peptide yielded a protonated molecular ion [M + H]+ of m/z 2789. The unequivocal sequence was deduced by automated Edman degradation as: DLWNSIKDMAAAAGRAALNAVTGMVNQ. The peptide exhibited an 80.76% identity with dermaseptin 3.1 from the leaf frog Agalychnis annae, and was therefore named Schistosoma mansoni dermaseptin-like peptide (SmDLP). Immunocytochemical staining using a primary antidermaseptin B2 antibody located SmDLP in acetabular glands of cercariae, in and around schistosomula, and in adult worms and their eggs. Dot-blotting confirmed its presence in extracts (cercariae and worms) and excretion/secretion (E/S) products (transforming cercariae and eggs). This was corroborated by use of a MALDI-ToF spectra database of E/S products from cercariae. Functional characterization of the peptide indicated that SmDLP had typical amphipathic antimicrobial peptide properties, i.e., the ability to lyse human erythrocytes causing a decrease in the levels of nitric oxide produced by monocytic cells. This last function strongly suggests that SmDLP plays a vital role in the parasite's immunoevasion strategy. The possibility that schistosomes acquired this gene from amphibians has been discussed by constructing a phylogenetic tree.
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Affiliation(s)
- Gerry A P Quinn
- Department of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland
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Martin LB, Hasselquist D, Wikelski M. Investment in immune defense is linked to pace of life in house sparrows. Oecologia 2006; 147:565-75. [PMID: 16450181 DOI: 10.1007/s00442-005-0314-y] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Accepted: 11/08/2005] [Indexed: 11/30/2022]
Abstract
The evidence for a relationship between life history and immune defense is equivocal, although the basic premise is intuitively appealing: animals that live short lives and reproduce early and rapidly should not waste resources on defenses they might never use. One possible reason for a lack of strong support for this hypothesis could be the inherent complexity of the vertebrate immune system. Indeed, different components of the vertebrate immune system vary in their relative costs and benefits, and therefore only some defenses may complement variation in species' life history. To address this hypothesis, we compared multiple types of immune activity between two populations of house sparrows (Passer domesticus) with distinct life histories, one from Colon, Panama, which lay small clutches over an extended breeding season (i.e., slow-living) and the other from Princeton, New Jersey, which lay larger clutches in a smaller window of time (i.e., fast-living). We expected (a) that more costly types of immune defenses would be stronger in the slow-living sparrows and (2) that the slow-living sparrows would show a greater increase in whole-body energy expenditure after immune challenge compared to their fast-living counterparts. We found that secondary antibody response to a novel antigen was more rapid and energetic investment in immune activity was greater in slow-living sparrows. However, cell-mediated immune activity was more robust in fast-living sparrows, and other measures of defense were not different between populations. These results provide partial support for a relationship between life history and immune defense in this species, but they also indicate that this relationship is not clear-cut. Further study is necessary to identify the influence of other factors, particular pathogen environment during development, on the architecture of the immune system of wild animals.
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Affiliation(s)
- Lynn B Martin
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
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