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Michael D Samuel - One of the best experts on this subject based on the ideXlab platform.
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mineral licks as environmental reservoirs of chronic wasting disease prions
PLOS ONE, 2018Co-Authors: Ian H Plummer, Chad J Johnson, Alexandra R Chesney, Joel A Pedersen, Michael D SamuelAbstract:Chronic wasting disease (CWD) is a fatal neurodegenerative disease of deer, elk, moose, and reindeer (Cervids) caused by misfolded prion proteins. The disease has been reported across North America and recently discovered in northern Europe. Transmission of CWD in wild Cervid populations can occur through environmental routes, but limited ability to detect prions in environmental samples has prevented the identification of potential transmission "hot spots". We establish widespread CWD prion contamination of mineral licks used by free-ranging Cervids in an enzootic area in Wisconsin, USA. We show mineral licks can serve as reservoirs of CWD prions and thus facilitate disease transmission. Furthermore, mineral licks attract livestock and other wildlife that also obtain mineral nutrients via soil and water consumption. Exposure to CWD prions at mineral licks provides potential for cross-species transmission to wildlife, domestic animals, and humans. Managing deer use of mineral licks warrants further consideration to help control outbreaks of CWD.
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temporal patterns of chronic wasting disease prion excretion in three Cervid species
Journal of General Virology, 2017Co-Authors: Ian H Plummer, Chad J Johnson, Joel A Pedersen, Scott D Wright, Michael D SamuelAbstract:Chronic wasting disease (CWD) is the only naturally occurring transmissible spongiform encephalopathy affecting free-ranging wildlife populations. Transmission of CWD occurs by direct contact or through contaminated environments; however, little is known about the temporal patterns of CWD prion excretion and shedding in wild Cervids. We tested the urine and faeces of three species of captive Cervids (elk, mule and white-tailed deer) at 6, 12, 18 and 24 months after oral inoculation to evaluate the temporal, species- and genotype-specific factors affecting the excretion of CWD prions. Although none of the animals exhibited clinical signs of CWD during the study, we determined that all three Cervid species were excreting CWD prions by 6 months post-inoculation. Faecal samples were consistently positive for CWD prions for all three Cervid species (88 %), and were more likely to be positive than urine samples (28 %). Cervids with genotypes encoding for the prion protein (PRNP) that were considered to be more susceptible to CWD were more likely to excrete CWD prions (94 %) than Cervids with genotypes considered to be less susceptible (64 %). All Cervids with CWD prions in their urine also had positive faeces (n=5), but the converse was not true. Our study is the first to demonstrate CWD prion excretion in urine by asymptomatic elk and mule deer. Our results indicate that the excretion of CWD prions in faeces and, to a lesser extent, urine may provide an important avenue for depositing prions in the environment.
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the role of genetics in chronic wasting disease of north american Cervids
Prion, 2012Co-Authors: Stacie J Robinson, Katherine I Orourke, Michael D Samuel, Chad J JohnsonAbstract:Chronic wasting disease (CWD) is a major concern for the management of North American Cervid populations. This fatal prion disease has led to declines in populations which have high CWD prevalence and areas with both high and low infection rates have experienced economic losses in wildlife recreation and fears of potential spill-over into livestock or humans. Research from human and veterinary medicine has established that the prion protein gene (Prnp) encodes the protein responsible for transmissible spongiform encephalopathies (TSEs). Polymorphisms in the Prnp gene can lead to different prion forms that moderate individual susceptibility to and progression of TSE infection. Prnp genes have been sequenced in a number of Cervid species including those currently infected by CWD (elk, mule deer, white-tailed deer, moose) and those for which susceptibility is not yet determined (caribou, fallow deer, sika deer). Over thousands of sequences examined, the Prnp gene is remarkably conserved within the family Cervidae; only 16 amino acid polymorphisms have been reported within the 256 amino acid open reading frame in the third exon of the Prnp gene. Some of these polymorphisms have been associated with lower rates of CWD infection and slower progression of clinical CWD. Here we review the body of research on Prnp genetics of North American Cervids. Specifically, we focus on known polymorphisms in the Prnp gene, observed genotypic differences in CWD infection rates and clinical progression, mechanisms for genetic TSE resistance related to both the Cervid host and the prion agent and potential for natural selection for CWD-resistance. We also identify gaps in our knowledge that require future research.
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chronic wasting disease in free ranging wisconsin white tailed deer
Emerging Infectious Diseases, 2003Co-Authors: Damien O Joly, Christine A Ribic, Julie A Langenberg, Kerry Beheler, Carl A Batha, Brian J Dhuey, Robert E Rolley, Gerald A Bartelt, Timothy R Van Deelen, Michael D SamuelAbstract:Three White-Tailed Deer shot within 5 km during the 2001 hunting season in Wisconsin tested positive for chronic wasting disease, a prion disease of Cervids. Subsequent sampling within 18 km showed a 3% prevalence (n=476). This prevalence indicates a significant range extension for chronic wasting disease into the eastern United States. Chronic wasting disease (CWD) is degenerative and usually considered to be fatal in White-tailed Deer (Odocoileus virginianus), Mule Deer (O. hemionus), and Elk (Cervus elaphus) associated with the presence of transmissible protease-resistant prion proteins (PrPcwd) (1,2). Although the transmission route of PrPcwd is unknown, it may be transmitted in deer and elk by direct or indirect contact from the environment (1,2). In experiments, clinical signs have appeared as early as 15 months after exposure (1) and include weight loss, anorexia, repetitive behaviors, hyperesthesia, and intractability. Signs progress to severe emaciation, extreme behavioral changes, excessive salivation, tremors, and mild ataxia (1,2). CWD was first recognized in captive Mule Deer in Colorado (3) and subsequently described in the free-ranging Cervid populations of Colorado and Wyoming (1); prevalence in these disease-endemic areas varies spatially and among the three sympatric Cervid species (4). Before its discovery in Wisconsin, CWD was detected in captive Cervid farms in Colorado, Nebraska, South Dakota, Oklahoma, Kansas, Montana (USA), as well as Alberta, Saskatchewan (Canada), and South Korea (1). Apart from the contiguous areas of Colorado, Wyoming, and Nebraska, CWD had previously only been detected in two free-ranging Mule Deer from Saskatchewan, one Mule Deer from South Dakota, and in a number of Mule Deer from the western slopes region of Colorado (1). Previously, no cases of CWD were reported east of the Mississippi River; however, subsequent to our research, CWD-positive Cervids were found in Minnesota (captive elk), and Wisconsin (captive White-tailed Deer). Further, west of Mississippi, CWD-positive Mule deer have been found in New Mexico and Utah, free-ranging White-tailed Deer in Saskatchewan, Canada, and captive White-tailed Deer in Alberta, Canada. On CWD-positive free-ranging Mule Deer was discovered in New Mexico.
Edward A Hoover - One of the best experts on this subject based on the ideXlab platform.
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detection of chronic wasting disease in mule and white tailed deer by rt quic analysis of outer ear
Scientific Reports, 2021Co-Authors: Natalia C Ferreira, Jorge M Charco, Jakob Plagenz, Christina D Orru, Nathanial D Denkers, Michael A Metrick, Andrew G Hughson, Karen A Griffin, Brent Race, Edward A HooverAbstract:Efforts to contain the spread of chronic wasting disease (CWD), a fatal, contagious prion disease of Cervids, would be aided by the availability of additional diagnostic tools. RT-QuIC assays allow ultrasensitive detection of prion seeds in a wide variety of Cervid tissues, fluids and excreta. The best documented antemortem diagnostic test involving RT-QuIC analysis targets lymphoid tissue in rectal biopsies. Here we have tested a more easily accessed specimen, ear pinna punches, using an improved RT-QuIC assay involving iron oxide magnetic extraction to detect CWD infections in asymptomatic mule and white-tailed deer. Comparison of multiple parts of the ear pinna indicated that a central punch spanning the auricular nerve provided the most consistent detection of CWD infection. When compared to results obtained from gold-standard retropharyngeal lymph node specimens, our RT-QuIC analyses of ear samples provided apparent diagnostic sensitivity (81%) and specificity (91%) that rivaled, or improved upon, those observed in previous analyses of rectal biopsies using RT-QuIC. These results provide evidence that RT-QuIC analysis of ear pinna punches may be a useful approach to detecting CWD infections in Cervids.
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evidence for distinct chronic wasting disease cwd strains in experimental cwd in ferrets
Journal of General Virology, 2012Co-Authors: Matthew R Perrott, Christina J Sigurdson, Gary L. Mason, Edward A HooverAbstract:Chronic wasting disease (CWD) is an evolving prion disease of Cervids (deer, elk and moose) that has been recognized in North America and Korea. Infection of non-Cervid reservoir or transport species in nature is not reported. However, the ferret (Mustela putorius furo) is susceptible to CWD after experimental inoculation. Here, we report that infection of ferrets with either of two ferret CWD isolates by various routes of exposure has revealed biologically distinct strain-like properties distinguished by different clinical progression and survival period. The isolates of ferret CWD were also differentiated by the distribution of the infectious prion protein (PrPCWD) in the brain and periphery, and by the proteinase K sensitivity of PrPCWD. These findings suggest that diversity in prion conformers exists in CWD-infected Cervids.
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detection of chronic wasting disease prions in salivary urinary and intestinal tissues of deer potential mechanisms of prion shedding and transmission
Journal of Virology, 2011Co-Authors: Nicholas J Haley, Mark D. Zabel, Glenn C Telling, Candace K Mathiason, Scott Carver, Edward A HooverAbstract:Efficient horizontal transmission is a signature trait of chronic wasting disease (CWD) in Cervids. Infectious prions shed into excreta appear to play a key role in this facile transmission, as has been demonstrated by bioassays of Cervid and transgenic species and serial protein misfolding cyclic amplification (sPMCA). However, the source(s) of infectious prions in these body fluids has yet to be identified. In the present study, we analyzed tissues proximate to saliva, urine, and fecal production by sPMCA in an attempt to elucidate this unique aspect of CWD pathogenesis. Oropharyngeal, urogenital, and gastrointestinal tissues along with blood and obex from CWD-exposed Cervids (comprising 27 animals and >350 individual samples) were analyzed and scored based on the apparent relative CWD burden. PrPCWD-generating activity was detected in a range of tissues and was highest in the salivary gland, urinary bladder, and distal intestinal tract. In the same assays, blood from the same animals and unseeded normal brain homogenate controls (n = 116 of 117) remained negative. The PrP-converting activity in peripheral tissues varied from 10−11- to 100-fold of that found in brain of the same animal. Deer with highest levels of PrPCWD amplification in the brain had higher and more widely disseminated prion amplification in excretory tissues. Interestingly, PrPCWD was not demonstrable in these excretory tissues by conventional Western blotting, suggesting a low prion burden or the presence of protease-sensitive infectious prions destroyed by harsh proteolytic treatments. These findings offer unique insights into the transmission of CWD in particular and prion infection and trafficking overall.
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detection of cwd prions in urine and saliva of deer by transgenic mouse bioassay
PLOS ONE, 2009Co-Authors: Nicholas J Haley, Mark D. Zabel, Glenn C Telling, Davis M Seelig, Edward A HooverAbstract:Chronic wasting disease (CWD) is a prion disease affecting captive and free-ranging Cervids (e.g. deer, elk, and moose). The mechanisms of CWD transmission are poorly understood, though bodily fluids are thought to play an important role. Here we report the presence of infectious prions in the urine and saliva of deer with chronic wasting disease (CWD). Prion infectivity was detected by bioassay of concentrated, dialyzed urine and saliva in transgenic mice expressing the Cervid PrP gene (Tg[CerPrP] mice). In addition, PrPCWD was detected in pooled and concentrated urine by protein misfolding cyclic amplification (PMCA). The concentration of abnormal prion protein in bodily fluids was very low, as indicated by: undetectable PrPCWD levels by traditional assays (western blot, ELISA) and prolonged incubation periods and incomplete TSE attack rates in inoculated Tg(CerPrP) mice (373±3days in 2 of 9 urine-inoculated mice and 342±109 days in 8 of 9 saliva-inoculated mice). These findings help extend our understanding of CWD prion shedding and transmission and portend the detection of infectious prions in body fluids in other prion infections.
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efficient in vitro amplification of chronic wasting disease prpres
Journal of Virology, 2007Co-Authors: Timothy D Kurt, Mark D. Zabel, Matthew R Perrott, Carol J Wilusz, Jeffrey Wilusz, Surachai Supattapone, Edward A HooverAbstract:Chronic wasting disease (CWD) of Cervids is associated with conversion of the normal Cervid prion protein, PrP(C), to a protease-resistant conformer, PrP(CWD). Here we report the use of both nondenaturing amplification and protein-misfolding cyclic amplification (PMCA) to amplify PrP(CWD) in vitro. Normal brains from deer, transgenic mice expressing Cervid PrP(C) [Tg(cerPrP)1536 mice], and ferrets supported amplification. PMCA using normal Tg(cerPrP)1536 brains as the PrP(C) substrate produced >6.5 x 10(9)-fold amplification after six rounds. Highly efficient in vitro amplification of PrP(CWD) is a significant step toward detection of PrP(CWD) in the body fluids or excreta of CWD-susceptible species.
Roman Croitor - One of the best experts on this subject based on the ideXlab platform.
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deer remains from the middle pleistocene site of gruta da aroeira portugal iberian faunal endemism and implications for hominin paleobiogeography
Quaternary Science Reviews, 2019Co-Authors: Roman Croitor, Montserrat Sanz, Joan DauraAbstract:Abstract The article presents a description of Cervid remains from the Middle Pleistocene Acheulean site of Gruta da Aroeira (= Galerias Pesadas) in central Portugal. The assemblage comprises the remains of four deer species: Cervus elaphus, Praedama cf. savini, Haploidoceros mediterraneus, and Dama cf. vallonnetensis, making Gruta da Aroeira the first site in the Iberian Peninsula at which the genus Haploidoceros has been documented in the Middle Pleistocene. Virtually all the Cervids documented at the site demonstrate a degree of endemism, including evolutionary modifications of skull, antlers and dentition or a reduction in body size. The unusual richness of the Cervid community at Gruta da Aroeira may be related to the specific biogeographic conditions of the Middle Pleistocene in Iberia. Thus, while the Iberian Peninsula’s geographical link with the temperate west Eurasian zone facilitated the dispersal of Cervids of palearctic origin into Iberia, it impeded the dispersal of ruminants from warmer, more arid areas. The endemic character of the Middle Pleistocene Cervids and the biodiversity of the Iberian Peninsula should shed some light on the paleobiogeography of Iberian hominins and their role in hominin hunting or their economic strategies.
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taxonomy and systematics of large sized deer of the genus praemegaceros portis 1920 Cervidae mammalia
Courier Forschungsinstitut Senckenberg, 2006Co-Authors: Roman CroitorAbstract:A taxonomical and systematic revision of the Cervid genus Praemegaceros PORTIS is proposed in the article. The genus Praemegaceros is known from the Pleistocene of Europe, from some Mediterranean islands and from the eastern Mediterranean area. It includes fi ve mainland species and an insular small-sized species. The type species, Praemegaceros dawkinsi, from the Middle Pleistocene of England and Northern France, is a small descent of the larger, Late Villafranchian P. obscurus. Three parallel lineages within the genus Praemegaceros are designated as subgenera: Praemegaceros, Orthogonoceros and Nesoleipoceros. Megaceroides JOLEAUD is suggested as an inappropriate genus name for this group of Cervids, because Megaceroides is typifi ed by the strongly specialised, endemic North African species M. algericus
Joan Daura - One of the best experts on this subject based on the ideXlab platform.
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deer remains from the middle pleistocene site of gruta da aroeira portugal iberian faunal endemism and implications for hominin paleobiogeography
Quaternary Science Reviews, 2019Co-Authors: Roman Croitor, Montserrat Sanz, Joan DauraAbstract:Abstract The article presents a description of Cervid remains from the Middle Pleistocene Acheulean site of Gruta da Aroeira (= Galerias Pesadas) in central Portugal. The assemblage comprises the remains of four deer species: Cervus elaphus, Praedama cf. savini, Haploidoceros mediterraneus, and Dama cf. vallonnetensis, making Gruta da Aroeira the first site in the Iberian Peninsula at which the genus Haploidoceros has been documented in the Middle Pleistocene. Virtually all the Cervids documented at the site demonstrate a degree of endemism, including evolutionary modifications of skull, antlers and dentition or a reduction in body size. The unusual richness of the Cervid community at Gruta da Aroeira may be related to the specific biogeographic conditions of the Middle Pleistocene in Iberia. Thus, while the Iberian Peninsula’s geographical link with the temperate west Eurasian zone facilitated the dispersal of Cervids of palearctic origin into Iberia, it impeded the dispersal of ruminants from warmer, more arid areas. The endemic character of the Middle Pleistocene Cervids and the biodiversity of the Iberian Peninsula should shed some light on the paleobiogeography of Iberian hominins and their role in hominin hunting or their economic strategies.
Chad J Johnson - One of the best experts on this subject based on the ideXlab platform.
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mineral licks as environmental reservoirs of chronic wasting disease prions
PLOS ONE, 2018Co-Authors: Ian H Plummer, Chad J Johnson, Alexandra R Chesney, Joel A Pedersen, Michael D SamuelAbstract:Chronic wasting disease (CWD) is a fatal neurodegenerative disease of deer, elk, moose, and reindeer (Cervids) caused by misfolded prion proteins. The disease has been reported across North America and recently discovered in northern Europe. Transmission of CWD in wild Cervid populations can occur through environmental routes, but limited ability to detect prions in environmental samples has prevented the identification of potential transmission "hot spots". We establish widespread CWD prion contamination of mineral licks used by free-ranging Cervids in an enzootic area in Wisconsin, USA. We show mineral licks can serve as reservoirs of CWD prions and thus facilitate disease transmission. Furthermore, mineral licks attract livestock and other wildlife that also obtain mineral nutrients via soil and water consumption. Exposure to CWD prions at mineral licks provides potential for cross-species transmission to wildlife, domestic animals, and humans. Managing deer use of mineral licks warrants further consideration to help control outbreaks of CWD.
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temporal patterns of chronic wasting disease prion excretion in three Cervid species
Journal of General Virology, 2017Co-Authors: Ian H Plummer, Chad J Johnson, Joel A Pedersen, Scott D Wright, Michael D SamuelAbstract:Chronic wasting disease (CWD) is the only naturally occurring transmissible spongiform encephalopathy affecting free-ranging wildlife populations. Transmission of CWD occurs by direct contact or through contaminated environments; however, little is known about the temporal patterns of CWD prion excretion and shedding in wild Cervids. We tested the urine and faeces of three species of captive Cervids (elk, mule and white-tailed deer) at 6, 12, 18 and 24 months after oral inoculation to evaluate the temporal, species- and genotype-specific factors affecting the excretion of CWD prions. Although none of the animals exhibited clinical signs of CWD during the study, we determined that all three Cervid species were excreting CWD prions by 6 months post-inoculation. Faecal samples were consistently positive for CWD prions for all three Cervid species (88 %), and were more likely to be positive than urine samples (28 %). Cervids with genotypes encoding for the prion protein (PRNP) that were considered to be more susceptible to CWD were more likely to excrete CWD prions (94 %) than Cervids with genotypes considered to be less susceptible (64 %). All Cervids with CWD prions in their urine also had positive faeces (n=5), but the converse was not true. Our study is the first to demonstrate CWD prion excretion in urine by asymptomatic elk and mule deer. Our results indicate that the excretion of CWD prions in faeces and, to a lesser extent, urine may provide an important avenue for depositing prions in the environment.
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the role of genetics in chronic wasting disease of north american Cervids
Prion, 2012Co-Authors: Stacie J Robinson, Katherine I Orourke, Michael D Samuel, Chad J JohnsonAbstract:Chronic wasting disease (CWD) is a major concern for the management of North American Cervid populations. This fatal prion disease has led to declines in populations which have high CWD prevalence and areas with both high and low infection rates have experienced economic losses in wildlife recreation and fears of potential spill-over into livestock or humans. Research from human and veterinary medicine has established that the prion protein gene (Prnp) encodes the protein responsible for transmissible spongiform encephalopathies (TSEs). Polymorphisms in the Prnp gene can lead to different prion forms that moderate individual susceptibility to and progression of TSE infection. Prnp genes have been sequenced in a number of Cervid species including those currently infected by CWD (elk, mule deer, white-tailed deer, moose) and those for which susceptibility is not yet determined (caribou, fallow deer, sika deer). Over thousands of sequences examined, the Prnp gene is remarkably conserved within the family Cervidae; only 16 amino acid polymorphisms have been reported within the 256 amino acid open reading frame in the third exon of the Prnp gene. Some of these polymorphisms have been associated with lower rates of CWD infection and slower progression of clinical CWD. Here we review the body of research on Prnp genetics of North American Cervids. Specifically, we focus on known polymorphisms in the Prnp gene, observed genotypic differences in CWD infection rates and clinical progression, mechanisms for genetic TSE resistance related to both the Cervid host and the prion agent and potential for natural selection for CWD-resistance. We also identify gaps in our knowledge that require future research.