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Higham JP, Stahl-Hennig C, Heistermann M. Urinary suPAR: a non-invasive biomarker of infection and tissue inflammation for use in studies of large free-ranging mammals. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191825. [PMID: 32257339 PMCID: PMC7062102 DOI: 10.1098/rsos.191825] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/17/2020] [Indexed: 06/11/2023]
Abstract
Studies of large free-ranging mammals incorporating physiological measurements typically require the collection of urine or faecal samples, due to ethical and practical concerns over trapping or darting animals. However, there is a dearth of validated biomarkers of immune activation and inflammation that can be measured non-invasively. We here evaluate the utility of urinary measurements of the soluble form of the urokinase plasminogen activator receptor (suPAR), for use as a health marker in studies of wild large mammals. We investigate how urinary suPAR concentrations change in response to viral infection and surgical trauma (inflammation), comparing it to the measurement of a marker of cellular immune activation, urinary neopterin (uNEO), in captive rhesus macaques. We then test the field utility of urinary suPAR, assessing the effects of soil and faecal contamination, sunlight, storage at different temperatures, freeze-thaw cycles, and lyophilization. We find that suPAR concentrations rise markedly in response to both infection and surgery-associated inflammation, unlike uNEO concentrations, which only rise in response to the former. Our field validation demonstrates that urinary suPAR is reasonably robust to many of the issues associated with field collection, sample processing, and storage, as long as samples can be stored in a freezer. Urinary suPAR is thus a promising biomarker applicable for monitoring various aspects of health in wild primates and potentially also other large mammals.
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Affiliation(s)
- James P. Higham
- Department of Anthropology, New York University, 25 Waverly Place, New York, NY 10003, USA
| | - Christiane Stahl-Hennig
- Unit of Infection Models, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen 37077, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen 37077, Germany
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2
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Heistermann M, Higham JP. Urinary neopterin, a non-invasive marker of mammalian cellular immune activation, is highly stable under field conditions. Sci Rep 2015; 5:16308. [PMID: 26549509 PMCID: PMC4637859 DOI: 10.1038/srep16308] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/12/2015] [Indexed: 01/02/2023] Open
Abstract
Studying immunity and immune function in ecology and evolution requires field studies, but there has been a dearth of non-invasive markers of immune activation available for studying large wild mammals. Recently, we analytically and biologically validated the measurement of urinary neopterin (NEO), a biomarker of cellular immune activation, in captive macaques. However, applying this to free-ranging settings is complicated by issues involving sample collection, processing, storage, and transport. Here, we collected urine samples from captive macaques and undertook experiments simulating common field issues. We tested the effects on urinary NEO sample measurements following: dirt and faecal contamination; storage at room temperature; differences in processing and long-term storage methods (freezing, lyophilising, blotting onto filter paper); and freeze-thaw cycles. Our results show that concentrations of urinary NEO are highly stable--they are not affected by soil or faecal contamination, can be collected on filter paper and stored for many months frozen or lyophilised with minimal effect, and are resistant to multiple 24 hr freeze-thaws. With the addition of a biocidal preservative, concentrations are even stable at room temperature for long periods. Urinary NEO is remarkably resilient, and is highly suitable for non-invasive field studies of cellular immune responses in wild large mammals.
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Affiliation(s)
- Michael Heistermann
- Endocrinology Laboratory, German Primate Centre, Leibniz Institute for Primate Research, Goettingen, Germany
| | - James P. Higham
- Department of Anthropology, New York University, New York, NY, USA
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3
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Edwards KL, McArthur HM, Liddicoat T, Walker SL. A practical field extraction method for non-invasive monitoring of hormone activity in the black rhinoceros. CONSERVATION PHYSIOLOGY 2014; 2:cot037. [PMID: 27293621 PMCID: PMC4732489 DOI: 10.1093/conphys/cot037] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 12/07/2013] [Accepted: 12/09/2013] [Indexed: 05/19/2023]
Abstract
Non-invasive hormone analysis is a vital tool in assessing an animal's adrenal and reproductive status, which can be beneficial to in situ and ex situ conservation. However, it can be difficult to employ these techniques when monitoring in situ populations away from controlled laboratory conditions, when electricity is not readily available. A practical method for processing faecal samples in the field, which enables samples to be extracted soon after defaecation and stored in field conditions for prolonged periods prior to hormone analysis, is therefore warranted. This study describes the development of an optimal field extraction method, which includes hand-shaking faecal material in 90% methanol, before loading this extract in a 40% solvent onto HyperSep™ C8 solid-phase extraction cartridges, stored at ambient temperatures. This method was successfully validated for measurement of adrenal and reproductive hormone metabolites in faeces of male and female black rhinoceros (Diceros bicornis) and was rigorously tested in controlled laboratory and simulated field conditions. All the hormones tested demonstrated between 83 and 94% and between 42 and 89% recovery of synthetic and endogenous hormone metabolites, respectively, with high precision of replication. Furthermore, results obtained following the developed optimal field extraction method were highly correlated with the control laboratory method. Cartridges can be stored at ambient (cool, dry or warm, humid) conditions for periods of up to 6 months without degradation, before re-extraction of hormone metabolites for analysis by enzyme immunoassay. The described method has great potential to be applied to monitor faecal reproductive and adrenal hormone metabolites in a wide variety of species and allows samples to be stored in the field for up to 6 months prior to analysis. This provides the opportunity to investigate hormone relationships within in situ populations, where equipment and facilities may previously have been limiting.
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Affiliation(s)
- Katie L. Edwards
- North of England Zoological Society, Chester Zoo, Caughall Road, Upton-by-Chester CH2 1LH, UK
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Hannah M. McArthur
- North of England Zoological Society, Chester Zoo, Caughall Road, Upton-by-Chester CH2 1LH, UK
- School of Life Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Tim Liddicoat
- Thermo Fisher Scientific, Tudor Road, Manor Park, Runcorn WA7 1TA, UK
| | - Susan L. Walker
- North of England Zoological Society, Chester Zoo, Caughall Road, Upton-by-Chester CH2 1LH, UK
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Mesa-Cruz JB, Brown JL, Kelly MJ. Effects of natural environmental conditions on faecal glucocorticoid metabolite concentrations in jaguars (Panthera onca) in Belize. CONSERVATION PHYSIOLOGY 2014; 2:cou039. [PMID: 27293660 PMCID: PMC4732494 DOI: 10.1093/conphys/cou039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 05/03/2023]
Abstract
In situ studies that rely on non-invasive faecal hormone monitoring are subject to problems due to potential changes in hormone concentrations in samples exposed to field conditions. In this study, we conducted an environmental validation for measurement of faecal glucocorticoid metabolites (FGMs) in jaguars (Panthera onca). We collected fresh faeces (e.g. no older than 8 h) from jaguars (six males and four females), housed at the Belize Zoo, and exposed them randomly to two environmental conditions: shade and sun. A control (first sub-sample) was immediately frozen, after which sub-samples were frozen daily over a 5 day period in both the dry and wet seasons. We quantified FGMs using a cortisol enzyme immunoassay (EIA) and a corticosterone radioimmunoassay (RIA), both capable of identifying relevant metabolites. Results indicated that FGMs assessed with the cortisol EIA were stable for 5 days during the dry season but for <1 day during the wet season, while FGMs assessed with the corticosterone RIA were stable for 5 days during both the dry and wet seasons. Exposure of jaguar faeces to sun or shade had no effect on FGM concentrations, despite significant differences in weather parameters. Analysis of faecal morphology proved unreliable in identifying faecal age. We conclude that the corticosterone RIA is suitable for assessing FGMs in free-ranging Belizean jaguars by surveying the same transects every 3-4 days in both seasons. The cortisol EIA can be used during the dry season, but there are possible shifts in metabolite immunoactivity in wet conditions. Assessment of adrenal activity in jaguars ranging areas of varying human disturbance is a timely application of this methodology in Belize.
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Affiliation(s)
- J. Bernardo Mesa-Cruz
- Department of Fish and Wildlife Conservation, Virginia Polytechnic and State University, Cheatham Hall, 310 West Campus Drive, Blacksburg, VA 24061, USA
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA
- Corresponding author: Department of Fish and Wildlife Conservation, Virginia Polytechnic and State University, Cheatham Hall, 310 West Campus Drive, Blacksburg, VA 24061, USA. Tel: +1 443 745 9544.
| | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, 1500 Remount Road, Front Royal, VA 22630, USA
| | - Marcella J. Kelly
- Department of Fish and Wildlife Conservation, Virginia Polytechnic and State University, Cheatham Hall, 310 West Campus Drive, Blacksburg, VA 24061, USA
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Freeman EW, Meyer JM, Putman SB, Schulte BA, Brown JL. Ovarian cycle activity varies with respect to age and social status in free-ranging elephants in Addo Elephant National Park, South Africa. CONSERVATION PHYSIOLOGY 2013; 1:cot025. [PMID: 27293609 PMCID: PMC4806622 DOI: 10.1093/conphys/cot025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/18/2013] [Accepted: 08/19/2013] [Indexed: 05/03/2023]
Abstract
Free-ranging African elephants live in a fission-fusion society, at the centre of which is the matriarch. Matriarchs are generally older females that guide their families to resources and co-ordinate group defense. While much is known about elephant society, knowledge is generally lacking about how age affects the physiology of wild elephants. Investigation of the ovarian activity of free-ranging elephants could provide insight into the reproductive ageing process, with implications for population management. Faecal samples were collected from 46 individuals ranging in age from 14 to 60 years for a 2-year period, and progestagen metabolite analyses were used to examine relationships between social status, age, season, and ovarian activity in female elephants in Addo Elephant National Park, South Africa. Social status was the strongest predictor of faecal progestagen metabolite concentrations in non-pregnant elephants, with grand matriarchs (n = 6) having the lowest values compared with matriarchs (n = 21) and non-matriarch females (n = 19). Likewise, social status and age were the strongest predictors of faecal progestagen metabolite concentrations in pregnant elephants (n = 27). The number of years since a non-pregnant female gave birth to her last calf (post-partum duration) was longer for older females with a higher social status, as well as during the dry season. Our results indicate that social standing and age of elephants are related to reproductive function, and that older females exhibit reductions in ovarian capacity. These results expand our understanding of reproduction and fertility throughout an elephant's lifespan, and the factors that impact gonadal function in free-ranging females. Given that possible over-abundance of elephants in areas such as Addo Elephant National Park is fuelling the debate over how best to manage these populations, knowledge about the reproductive potential of high-ranking females can provide managers with biological data to identify the best candidates for controlling growth through translocation or contraception.
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Affiliation(s)
- Elizabeth W. Freeman
- New Century College, George Mason University, Fairfax, VA 22030, USA
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Jordana M. Meyer
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Sarah B. Putman
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Bruce A. Schulte
- Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA
| | - Janine L. Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
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Watson R, Munro C, Edwards KL, Norton V, Brown JL, Walker SL. Development of a versatile enzyme immunoassay for non-invasive assessment of glucocorticoid metabolites in a diversity of taxonomic species. Gen Comp Endocrinol 2013; 186:16-24. [PMID: 23462197 DOI: 10.1016/j.ygcen.2013.02.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 01/25/2013] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
Endocrinology is a useful tool for conservation biologists and animal managers, and measuring glucocorticoids can help understand biological mechanisms associated with species decline and animal welfare. The current study describes the development and optimization of a glucocorticoid enzyme immunoassay (EIA) to non-invasively assess adrenal activity in a variety of taxa. The antiserum (CJM006) was raised in rabbits to a corticosterone-3-CMO-BSA immunogen and used in a standard competitive EIA system. However, the EIA initially produced results with unacceptably high inter-assay variation, attributed to consistent patterns observed within the optical density of developing plates. To determine the cause of this variability, a number of factors were examined using synthetic corticosterone standard and endogenous faecal extract, including: plate type (Nunc MaxiSorp® II versus Immulon IB plates); the use of non-specific secondary antibody; type (artificial versus natural) and presence (light versus dark) of light during incubation; plate loading temperature (4°C versus room temperature); and substrate reagent temperature (4°C versus room temperature). Results indicated that variability was associated with plate location effects, which were not initially detected because control samples were always run in the same positions across plates. Light and temperature were the two major factors that affected EIA reliability. For this assay, the standard protocol required slight modification, with the optimal protocol using Nunc MaxiSorp® plates, room temperature substrate reagents and dark incubation conditions. Following optimization, this EIA was then validated biochemically for 38 species, through parallel displacement curves and interference assessment tests of faecal and urine samples. Additionally, biological validation was performed opportunistically in a subset of species, with use of this EIA demonstrating significant elevations in faecal glucocorticoid metabolites following potentially challenging events. In summary, this glucocorticoid EIA cross-reacts with excreted glucocorticoid metabolites across a wide range of taxa, including ungulates, primates, felids, birds, rodents and amphibians. We conclude that when used with optimal reagent and incubation conditions, this EIA will be useful for non-invasive monitoring of adrenal activity in a wide range of wildlife species.
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Affiliation(s)
- Rebecca Watson
- North of England Zoological Society, Chester Zoo, Chester CH2 1LH, UK
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Kalbitzer U, Heistermann M. Long‐term storage effects in steroid metabolite extracts from baboon (
Papio
sp.) faeces – a comparison of three commonly applied storage methods. Methods Ecol Evol 2013. [DOI: 10.1111/2041-210x.12054] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Urs Kalbitzer
- Cognitive Ethology Laboratory German Primate Center (DPZ) Kellnerweg 4 37077 Göttingen Germany
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8
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Murray CM, Heintz MR, Lonsdorf EV, Parr LA, Santymire RM. Validation of a field technique and characterization of fecal glucocorticoid metabolite analysis in wild chimpanzees (Pan troglodytes). Am J Primatol 2013; 75:57-64. [PMID: 22968979 PMCID: PMC3619224 DOI: 10.1002/ajp.22078] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 07/19/2012] [Accepted: 08/09/2012] [Indexed: 11/09/2022]
Abstract
Monitoring adrenocortical activity in wild primate populations is critical, given the well-documented relationship between stress, health, and reproduction. Although many primate studies have quantified fecal glucocorticoid metabolite (FGM) concentrations, it is imperative that researchers validate their method for each species. Here, we describe and validate a technique for field extraction and storage of FGMs in wild chimpanzees (Pan troglodytes). Our method circumvents many of the logistical challenges associated with field studies while yielding similar results to a commonly used laboratory method. We further validate that our method accurately reflects stress physiology using an adrenocorticotropic hormone challenge in a captive chimpanzee and an FGM peak at parturition in a wild subject. Finally, we quantify circadian patterns for FGMs for the first time in this species. Understanding these patterns may allow researchers to directly link specific events with the stress response.
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Affiliation(s)
- Carson M Murray
- Department of Conservation and Science, Lincoln Park Zoo, Chicago, Illinois, USA.
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Shutt K, Setchell JM, Heistermann M. Non-invasive monitoring of physiological stress in the Western lowland gorilla (Gorilla gorilla gorilla): validation of a fecal glucocorticoid assay and methods for practical application in the field. Gen Comp Endocrinol 2012; 179:167-77. [PMID: 22926327 DOI: 10.1016/j.ygcen.2012.08.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 08/02/2012] [Accepted: 08/05/2012] [Indexed: 10/28/2022]
Abstract
Enzymeimmunoassays (EIAs) allow researchers to monitor stress hormone output via measurement of fecal glucocorticoid metabolites (FGCMs) in many vertebrates. They can be powerful tools which allow the acquisition of otherwise unobtainable physiological information from both captive animals and wild animals in remote forest habitats, such as great apes. However, methods for hormone measurement, extraction and preservation need to be adapted and validated for field settings. In preparation for a field study of Western lowland gorillas (Gorilla gorilla gorilla) in the Central African Republic we used samples from captive gorillas collected around opportunistic stressful situations to test whether four different glucocorticoid EIAs reflected adrenocortical activity reliably and to establish the lag-time from the stressor to peak excretion. We also validated a field extraction technique and established a simple, non-freezer-reliant method to preserve FGCMs in extracts long-term. We determined the rate of FGCM change over 28 days when samples cannot be extracted immediately and over 12h when feces cannot be preserved immediately in alcohol. Finally, we used repeat samples from identified individuals to test for diurnal variation in FGCM output. Two group-specific assays measuring major cortisol metabolites detected the predicted FGCM response to the stressor reliably, whereas more specific cortisol and corticosterone assays were distinctly less responsive and thus less useful. We detected a lag time of 2-3 days from stressor to peak FGCM excretion. Our field extraction method performed as well as an established laboratory extraction method and FGCMs in dried extracts stored at ambient temperatures were as stable as those at -20 °C over 1 yr. Hormones in non-extracted feces in alcohol were stable up to 28 days at ambient temperatures. FGCMs in un-fixed gorilla feces deteriorated to almost 50% of the original values within 6h under field conditions. We detected no diurnal variation in FGCMs in samples from wild gorillas. Our study highlights the importance of thorough biological and immunological validation of FGCM assays, and presents validated, practical methods for the application of non-invasive adrenocortical monitoring techniques to field conservation contexts where it is crucially needed.
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Affiliation(s)
- Kathryn Shutt
- Department of Anthropology, Durham University, DH1 3LE, Durham, UK.
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10
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HILDEBRANDT TB, LUEDERS I, HERMES R, GOERITZ F, SARAGUSTY J. Anatomical, Physiological, Behavioral and Pathological Aspects of the Estrous Cycle in Elephants. ACTA ACUST UNITED AC 2012. [DOI: 10.5686/jjzwm.17.97] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Thomas B HILDEBRANDT
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Imke LUEDERS
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Robert HERMES
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Frank GOERITZ
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
| | - Joseph SARAGUSTY
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research
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Loeding E, Thomas J, Bernier D, Santymire R. Using Fecal Hormonal and Behavioral Analyses to Evaluate the Introduction of Two Sable Antelope at Lincoln Park Zoo. J APPL ANIM WELF SCI 2011; 14:220-46. [DOI: 10.1080/10888705.2011.576968] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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