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Craig M. Shuttleworth - One of the best experts on this subject based on the ideXlab platform.
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assessing a potential non invasive method for viral diagnostic purposes in european squirrels
Hystrix-italian Journal of Mammalogy, 2019Co-Authors: David J. Everest, Anna Meredith, Elspeth Milne, Dannielle Amber Rose Tolhurstcherriman, Hannah Davies, Akbar Dastjerdi, Adam Ashton, T Blackett, Aileen C Mill, Craig M. ShuttleworthAbstract:Viral infections globally threaten wild and captive mammal populations, with surveillance options limited by a lack of non-invasive diagnostics; especially when infection is asymptomatic in nature. We explored the potential for hair samples collected from red (Sciurus vulgaris) and grey (Sciurus carolinensis) squirrels to provide a means of screening for adenovirus (ADV) and squirrelpox virus (SQPV) using evolving polymerase chain reaction (PCR) assays. An initial pilot study phase utilised samples opportunistically harvested from grey squirrels controlled in Gwynedd, United Kingdom (UK). The screening of 319 grey squirrel carcasses revealed 58% spleen ADV DNA qPCR and 69% SQPV antibody enzyme linked immunosorbent assay (ELISA) positives. We developed new nested ADV and SQPV qPCRs and examined tail hair samples from a sub-set of 80 of these 319 sampled squirrels and these assays amplified ADV and SQPV DNA in a higher proportion of animals than the original qPCR (94% and 21% respectively). Tail hair samples obtained from six Cumbrian red squirrels which had died from squirrelpox disease also revealed 100% SQPV and 50% ADV DNA positive by the nested qPCR assays. These findings indicate enhanced sensitivity for the new platform. The integration of this non-invasive approach in assessing viral infection has wide application in epidemiological studies of wild mammal populations, in particular, during conservation translocations, where asymptomatic infections are of concern.
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british red squirrels remain the only known wild rodent host for leprosy bacilli
Frontiers in Veterinary Science, 2019Co-Authors: Annakatarina Schilling, Claudia Romeo, Nicola Ferrari, Benoit Pisanu, Maria Vittoria Mazzamuto, Rainer G. Ulrich, Charlotte Avanzi, Philippe Busso, Joyce Mcluckie, Craig M. ShuttleworthAbstract:Eurasian red squirrels (Sciurus vulgaris) in the British Isles are the most recently discovered animal reservoir for the leprosy bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Initial data suggest that prevalence of leprosy infection is variable and often low in different squirrel populations. Nothing is known about the presence of leprosy bacilli in other wild squirrel species despite two others (Siberian chipmunk [Tamias sibiricus], and Thirteen-lined ground squirrel [Ictidomys tridecemlineatus]) having been reported to be susceptible to experimental infection with M. leprae. Rats, a food-source in some countries where human leprosy occurs, have been suggested as potential reservoirs for leprosy bacilli, but no evidence supporting this hypothesis is currently available. We screened 301 squirrel samples covering four species (96 Eurasian red squirrels, 67 Eastern grey squirrels (Sciurus carolinensis), 35 Siberian chipmunks, and 103 Pallas’s squirrels (CalloSciurus erythraeus)) from Europe and 72 Mexican white-throated woodrats (Neotoma albigula) for the presence of M. leprae and M. lepromatosis using validated PCR protocols. No DNA from leprosy bacilli was detected in any of the samples tested. Given our sample-size, the pathogen should have been detected if the prevalence and/or bacillary load in the populations investigated were similar to those found for British red squirrels.
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Table_1_British Red Squirrels Remain the Only Known Wild Rodent Host for Leprosy Bacilli.XLSX
2019Co-Authors: Annakatarina Schilling, Claudia Romeo, Nicola Ferrari, Benoit Pisanu, Maria Vittoria Mazzamuto, Rainer G. Ulrich, Charlotte Avanzi, Philippe Busso, Joyce Mcluckie, Craig M. ShuttleworthAbstract:Eurasian red squirrels (Sciurus vulgaris) in the British Isles are the most recently discovered animal reservoir for the leprosy bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Initial data suggest that prevalence of leprosy infection is variable and often low in different squirrel populations. Nothing is known about the presence of leprosy bacilli in other wild squirrel species despite two others (Siberian chipmunk [Tamias sibiricus], and Thirteen-lined ground squirrel [Ictidomys tridecemlineatus]) having been reported to be susceptible to experimental infection with M. leprae. Rats, a food-source in some countries where human leprosy occurs, have been suggested as potential reservoirs for leprosy bacilli, but no evidence supporting this hypothesis is currently available. We screened 301 squirrel samples covering four species [96 Eurasian red squirrels, 67 Eastern gray squirrels (Sciurus carolinensis), 35 Siberian chipmunks, and 103 Pallas's squirrels (CalloSciurus erythraeus)] from Europe and 72 Mexican white-throated woodrats (Neotoma albigula) for the presence of M. leprae and M. lepromatosis using validated PCR protocols. No DNA from leprosy bacilli was detected in any of the samples tested. Given our sample-size, the pathogen should have been detected if the prevalence and/or bacillary load in the populations investigated were similar to those found for British red squirrels.
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Assessing causes and significance of red squirrel ( Sciurus vulgaris ) mortality during regional population restoration: An applied conservation perspective
Hystrix-italian Journal of Mammalogy, 2015Co-Authors: Craig M. Shuttleworth, David J. Everest, A. Lisa Signorile, Peter W. W. LurzAbstract:Red squirrel ( Sciurus vulgaris ) mortality was monitored opportunistically during the period 2004 to 2013 on the island of Anglesey in North Wales. Road traffic proved a most significant cause of death (48%) mirroring the findings of earlier United Kingdom (UK) studies. Red squirrels were also found to have died from a range of pathological infections and disease previously unrecorded in Wales. These data have increased our knowledge on the national distribution of such causal factors. The study found male red squirrels were less likely to have an adenovirus infection than females and that animals dying from disease had a lower body mass than those associated with a traumatic death. No red squirrels were found with squirrelpox infection or antibodies to this virus which reinforces earlier findings from Anglesey that intensive grey squirrel ( Sciurus carolinensis ) culling reduced the prevalence of this infection within sympatric populations. Finally we highlight the potential intra and inter-specific infection risk presented by supplemental feeding. Download the complete issue.
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pcr detection of adenovirus in grey squirrels on anglesey
Veterinary Record, 2009Co-Authors: David J. Everest, Sylvia S. Grierson, Mark F Stidworthy, Craig M. ShuttleworthAbstract:We wish to report the identification, using PCR techniques, of adenovirus in grey squirrels ( Sciurus carolinensis ) from Anglesey. To our knowledge, this is the first time that adenovirus DNA has been amplified from this species. Retrospective analysis of postmortem tissues and ongoing prospective
John Gurnell - One of the best experts on this subject based on the ideXlab platform.
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Epizootiology and pathologic findings associated with a newly described adenovirus in the red squirrel, Sciurus vulgaris.
Journal of wildlife diseases, 2011Co-Authors: David Martínez-jiménez, John Gurnell, David L. Graham, David Couper, Maria Benkö, Sandra Schöniger, Anthony W. SainsburyAbstract:An infectious disease caused by Squirrelpox virus has contributed to the decline of red squirrels, Sciurus vulgaris, in the British Isles. Because of the heightened disease surveillance activity in red squirrels, adenovirus infection with associated mortality has been detected. Adenoviral disease is described in other rodent species usually associated with stressors. Here we 1) describe the pathologic findings in red squirrels found dead with adenoviral infection and gastrointestinal disease, and 2) investigate the epizootiology of the disease through pathologic investigation, scanning surveillance, and virologic studies. Ten red squirrels involved in conservation studies were diagnosed with adenoviral infection by electron microscopy or PCR. All squirrels exhibited diarrhea and small intestinal inflammation or hemorrhage was evident in seven cases. Lesions indicative of splenic lymphocytolysis were observed in one squirrel and leukocytic hepatitis in another. No adenovirus was detected in grey squirrels, Sciurus carolinensis, inhabiting the same forest area, but previous serologic studies showed that grey squirrels cannot be discounted as a reservoir of the virus. Scanning surveillance showed that 12% of 493 red squirrels had diarrheal disease and two of 13 free-living red squirrels with diarrheal disease had adenovirus infection. Adenoviral disease in declining free-living wild red squirrel populations in the British Isles occurs at a detectable frequency and its impact on the conservation of this species deserves further attention.
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Monitoring red squirrels Sciurus vulgaris and grey squirrels Sciurus carolinensis in Britain
Mammal Review, 2004Co-Authors: John Gurnell, Peter W. W. Lurz, Mark D. F. Shirley, S. Cartmel, P. J. Garson, L. Magris, J. SteeleAbstract:1. In Britain, five indirect methods have been used to survey for the presence of red Sciurus vulgaris and grey squirrels S. carolinensis and to monitor population trends through time. These are: visual counts along line transects, the use of hair tubes, counts of dreys, cone line feeding transects in conifer forests and feeding signs on whole maize bait at feeding stations. 2. Drey counts and cone feeding transects cannot differentiate between red and grey squirrels and are not suitable for areas where both species may be present. Hair tubes require expertise and facilities to identify hairs to species, and the relationship between tube visits and animal density in different habitats is only known for red squirrels in Sitka spruce Picea sitchensis dominated plantations. Visual counts along line transects are the simplest method to do and require little equipment. However, in general, few squirrels are seen in a single count which leads to difficulties in estimating densities. 3. In this paper we present data from several studies carried out in Britain to illustrate the type of data that may be collected, and to evaluate their accuracy and precision with which they could detect population change. Hair tube lines and drey counts required the fewest number of samples to detect population change. When effort was also considered, visual transects and drey counts were more economical. However, none of the monitoring methods discussed is very precise and it may be best to monitor squirrels only in terms of relative changes in numbers or indices of numbers through time. 4. Our results for red and grey squirrels also illustrated that the number of samples required to detect population change is likely to differ according to the size of the survey area. Monitoring programmes should therefore be carefully planned in relation to spatial scale in order to be able to detect real population changes. Species-specific, quantitative thresholds to determine the significance of detected declines may need to be established for threatened UK mammals and assessed in relation to what would constitute a significant decline and whether it requires management intervention.
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Grey squirrels have high seroprevalence to a parapoxvirus associated with deaths in red squirrels
Animal Conservation, 2000Co-Authors: Anthony W. Sainsbury, P. F. Nettleton, Janice Gilray, John GurnellAbstract:The population of red squirrels (Sciurus vulgaris) in the British Isles is in decline and is being supplanted by the grey squirrel (Sciurus carolinensis). It has been suggested that parapoxvirus-associated disease has caused significant mortality in red squirrels and that grey squirrels are the source of the virus. A direct enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of antibody to squirrel parapoxvirus. We tested 140 sera from red squirrels and 223 from grey squirrels from different populations in the UK. A high percentage (61%) of apparently healthy grey squirrels, were found to have been exposed to the parapoxvirus. Only 2.86% (4/140) of red squirrels had antibody and three of these animals had parapoxvirus-associated disease. We postulate that the grey squirrel may act as a reservoir host for the virus.
Olin E Rhodes - One of the best experts on this subject based on the ideXlab platform.
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eleven microsatellite markers for the eastern gray squirrel Sciurus carolinensis and their utility in eastern fox squirrels Sciurus niger and red squirrels tamiaSciurus hudsonicus
Conservation Genetics Resources, 2013Co-Authors: Jennifer A Fike, Cecilia Hennessy, Michael L Kennedy, Olin E RhodesAbstract:The eastern gray squirrel (Sciurus carolinensis) often serves as a model organism for investigations of wildlife ecology. The authors developed 11 polymorphic microsatellite markers to facilitate future research questions. The number of alleles per locus ranged from three to ten and observed heterozygosities ranged from 0.143 to 0.786. Interspecific screening revealed that several loci were polymorphic in Sciurus niger (eight loci) and TamiaSciurus hudsonicus (four loci). These markers will aid in investigations of movements, social structure and mating tactics of eastern gray squirrel populations.
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characterization of twenty six polymorphic microsatellite markers for the fox squirrel Sciurus niger and their utility in gray squirrels Sciurus carolinensis and red squirrels tamiaSciurus hudsonicus
Conservation Genetics, 2009Co-Authors: Jennifer A Fike, Olin E RhodesAbstract:Twenty-six polymorphic microsatellite markers were developed for the fox squirrel (Sciurus niger). The number of alleles ranged from 2 to 11 and observed heterozygosities ranged from 0.037 to 0.815. Preliminary screening revealed that numerous loci also were polymorphic in other squirrel species: Sciurus carolinensis and TamiaSciurus hudsonicus. These loci should be useful tools for investigating the social structure, mating tactics and movement behavior of fox squirrels.
Claudio Tadeu Danielribeiro - One of the best experts on this subject based on the ideXlab platform.
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detection of signal regulatory protein α in saimiri sciureus squirrel monkey by anti human monoclonal antibody
Frontiers in Immunology, 2017Co-Authors: Hugo Amorim Dos Santos De Souza, Edmar Henrique Costacorrea, Cesare Biancojunior, Marcia Cristina Ribeiro Andrade, Josue Da Costa Limajunior, Lilian Rose Prattriccio, Claudio Tadeu Danielribeiro, Paulo Renato Rivas TotinoAbstract:Non-human primates (NHP) are suitable models for studying different aspects of the human system, including pathogenesis and protective immunity to many diseases. However, the lack of specific immunological reagents for neo-tropical monkeys, such as Saimiri sciureus, is still a major factor limiting studies in these models. An alternative strategy to circumvent this obstacle has been the selection of immunological reagents directed to humans, which present cross-reactivity with NHP molecules. In this context and considering the key role of inhibitory immunoreceptors-such as the signal regulatory protein α (SIRPα)-in the regulation of immune responses, in the present study, we attempted to evaluate the ability of anti-human SIRPα monoclonal antibodies to recognize SIRPα in antigen-presenting S. sciureus peripheral blood mononuclear cells (PBMC). As shown by flow cytometry analysis, the profile of anti-SIRPα staining as well as the levels of SIRPα-positive cells in PBMC from S. sciureus were similar to those observed in human PBMC. Furthermore, using anti-SIRPα monoclonal antibody, it was possible to detect a decrease of the SIRPα levels on surface of S. sciureus cells after in vitro stimulation with lipopolysaccharides. Finally, using computed-based analysis, we observed a high degree of conservation of SIRPα across six species of primates and the presence of shared epitopes in the extracellular domain between humans and Saimiri genus that could be targeted by antibodies. In conclusion, we have identified a commercially available anti-human monoclonal antibody that is able to detect SIRPα of S. sciureus monkeys and that, therefore, can facilitate the study of the immunomodulatory role of SIRPα when S. sciureus is used as a model.
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increased plasmodium falciparum parasitemia in non splenectomized saimiri sciureus monkeys treated with clodronate liposomes
Frontiers in Cellular and Infection Microbiology, 2017Co-Authors: Janaiara A. Cunha, Leonardo J. M. Carvalho, Evelyn K. P. Riccio, Igor J. Da Silva, Pierre Druilhe, Cesare Biancojunior, Marcia Cristina Ribeiro Andrade, Lilian Rose Prattriccio, Marcelo Pelajomachado, Claudio Tadeu DanielribeiroAbstract:A major constraint in the study of Plasmodium falciparum malaria, including vaccine development, lies on the parasite’s strict human host specificity and therefore the shortage of animal experimental models able to harbor human plasmodia. The best experimental models are neo-tropical primates of the genus Saimiri and Aotus, but they require splenectomy to reduce innate defences for achieving high and consistent parasitemias, an important limitation. Clodronate-liposomes (CL) have been successfully used to deplete monocytes/macrophages in several experimental models. We investigated whether a reduction in the numbers of phagocytic cells by CL would improve the development of P. falciparum parasitemia in non-splenectomized Saimiri sciureus monkeys. Depletion of S. sciureus splenocytes after in vitro incubation with CL was quantified using anti-CD14 antibodies and flow cytometry. Non-infected and P. falciparum-infected S. sciureus were injected intravenously twice a week with either CL at a low rate of either 0.5 or 1 mL (5mg/mL) or phosphate buffered saline (PBS). Animals were monitored during infection and treated with mefloquine. After treatment and euthanasia, spleen and liver were collected for histological analysis. In vitro CL depleted S. sciureus splenic monocyte/macrophage population in a dose- and time-dependent manner. In vivo, half of P. falciparum-infected S. sciureus treated with CL 0.5 mL, and two-thirds of those treated with CL 1 mL developed high parasitemias requiring mefloquine treatment, whereas all control animals were able to self-control parasitemia without the need for antimalarial treatment. CL-treated infected S. sciureus showed a marked decrease in the degree of splenomegaly despite higher parasitemias, compared to PBS-treated animals. Histological evidence of partial monocyte/macrophage depletion, decreased hemozoin phagocytosis and decreased iron recycling was observed in both the spleen and liver of CL-treated infected S. sciureus. CL is capable of promoting higher parasitemia in P. falciparum-infected S. sciureus, associated with evidence of partial macrophage depletion in the spleen and liver. Macrophage depletion by CL is therefore a practical and viable alternative to surgical splenectomy in this experimental model.
David J. Everest - One of the best experts on this subject based on the ideXlab platform.
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assessing a potential non invasive method for viral diagnostic purposes in european squirrels
Hystrix-italian Journal of Mammalogy, 2019Co-Authors: David J. Everest, Anna Meredith, Elspeth Milne, Dannielle Amber Rose Tolhurstcherriman, Hannah Davies, Akbar Dastjerdi, Adam Ashton, T Blackett, Aileen C Mill, Craig M. ShuttleworthAbstract:Viral infections globally threaten wild and captive mammal populations, with surveillance options limited by a lack of non-invasive diagnostics; especially when infection is asymptomatic in nature. We explored the potential for hair samples collected from red (Sciurus vulgaris) and grey (Sciurus carolinensis) squirrels to provide a means of screening for adenovirus (ADV) and squirrelpox virus (SQPV) using evolving polymerase chain reaction (PCR) assays. An initial pilot study phase utilised samples opportunistically harvested from grey squirrels controlled in Gwynedd, United Kingdom (UK). The screening of 319 grey squirrel carcasses revealed 58% spleen ADV DNA qPCR and 69% SQPV antibody enzyme linked immunosorbent assay (ELISA) positives. We developed new nested ADV and SQPV qPCRs and examined tail hair samples from a sub-set of 80 of these 319 sampled squirrels and these assays amplified ADV and SQPV DNA in a higher proportion of animals than the original qPCR (94% and 21% respectively). Tail hair samples obtained from six Cumbrian red squirrels which had died from squirrelpox disease also revealed 100% SQPV and 50% ADV DNA positive by the nested qPCR assays. These findings indicate enhanced sensitivity for the new platform. The integration of this non-invasive approach in assessing viral infection has wide application in epidemiological studies of wild mammal populations, in particular, during conservation translocations, where asymptomatic infections are of concern.
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Assessing causes and significance of red squirrel ( Sciurus vulgaris ) mortality during regional population restoration: An applied conservation perspective
Hystrix-italian Journal of Mammalogy, 2015Co-Authors: Craig M. Shuttleworth, David J. Everest, A. Lisa Signorile, Peter W. W. LurzAbstract:Red squirrel ( Sciurus vulgaris ) mortality was monitored opportunistically during the period 2004 to 2013 on the island of Anglesey in North Wales. Road traffic proved a most significant cause of death (48%) mirroring the findings of earlier United Kingdom (UK) studies. Red squirrels were also found to have died from a range of pathological infections and disease previously unrecorded in Wales. These data have increased our knowledge on the national distribution of such causal factors. The study found male red squirrels were less likely to have an adenovirus infection than females and that animals dying from disease had a lower body mass than those associated with a traumatic death. No red squirrels were found with squirrelpox infection or antibodies to this virus which reinforces earlier findings from Anglesey that intensive grey squirrel ( Sciurus carolinensis ) culling reduced the prevalence of this infection within sympatric populations. Finally we highlight the potential intra and inter-specific infection risk presented by supplemental feeding. Download the complete issue.
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Adenovirus in a red squirrel (Sciurus vulgaris) from Scotland
The Veterinary record, 2010Co-Authors: David J. Everest, Sylvia S. Grierson, Anna Meredith, Elspeth MilneAbstract:The red squirrel ( Sciurus vulgaris ) has been in decline in Great Britain for decades and numbers are presently estimated at 160,000, in various locations, with approximately 120,000 of these resident in Scotland. The role of the grey squirrel ( Sciurus carolinensis ) in this decline, as a vector
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pcr detection of adenovirus in grey squirrels on anglesey
Veterinary Record, 2009Co-Authors: David J. Everest, Sylvia S. Grierson, Mark F Stidworthy, Craig M. ShuttleworthAbstract:We wish to report the identification, using PCR techniques, of adenovirus in grey squirrels ( Sciurus carolinensis ) from Anglesey. To our knowledge, this is the first time that adenovirus DNA has been amplified from this species. Retrospective analysis of postmortem tissues and ongoing prospective
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adenovirus associated deaths in red squirrels on anglesey
Veterinary Record, 2008Co-Authors: David J. Everest, Mark F Stidworthy, Craig M. ShuttleworthAbstract:SIR, — Squirrel poxvirus is an important pathogen among native British red squirrels ( Sciurus vulgaris ) and a considerable factor in their continued decline ([Rushton and others 2006][1]). However, there is increasing evidence of significant adenovirus-associated disease. Enteric adenoviral
