Experimental transmission of ovine atypical scrapie to cattle
Timm Konold, John Spiropoulos, Janet Hills, Hasina Abdul, Saira Cawthraw, Laura Phelan, Amy McKenna, Lauren Read, Sara Canoyra, Alba Marín-Moreno & Juan María Torres
Veterinary Research volume 54, Article number: 98 (2023)
Abstract
Classical bovine spongiform encephalopathy (BSE) in cattle was caused by the recycling and feeding of meat and bone meal contaminated with a transmissible spongiform encephalopathy (TSE) agent but its origin remains unknown. This study aimed to determine whether atypical scrapie could cause disease in cattle and to compare it with other known TSEs in cattle. Two groups of calves (five and two) were intracerebrally inoculated with atypical scrapie brain homogenate from two sheep with atypical scrapie. Controls were five calves intracerebrally inoculated with saline solution and one non-inoculated animal. Cattle were clinically monitored until clinical end-stage or at least 96 months post-inoculation (mpi). After euthanasia, tissues were collected for TSE diagnosis and potential transgenic mouse bioassay. One animal was culled with BSE-like clinical signs at 48 mpi. The other cattle either developed intercurrent diseases leading to cull or remained clinical unremarkable at study endpoint, including control cattle. None of the animals tested positive for TSEs by Western immunoblot and immunohistochemistry. Bioassay of brain samples from the clinical suspect in Ov-Tg338 and Bov-Tg110 mice was also negative. By contrast, protein misfolding cyclic amplification detected prions in the examined brains from atypical scrapie-challenged cattle, which had a classical BSE-like phenotype. This study demonstrates for the first time that a TSE agent with BSE-like properties can be amplified in cattle inoculated with atypical scrapie brain homogenate.
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This is the first study in cattle inoculated with naturally occurring scrapie isolates that found the presence of prions resembling classical BSE in bovine brain although this was limited to detection by the ultrasensitive PMCA. The results from thermostability assay confirmed that the isolates were as thermoresistant as the BSE agent as proven in other studies [36, 48]. Previous PMCA studies with various British atypical scrapie isolates did not find any evidence of amplification [49, 50]. This may be explained by the use of ovine brain as substrate rather than brain from Bov-Tg110 mice, which may facilitate conversion to classical BSE prions.
Two hypotheses for prion strain propagation in cross-species transmission experiments have been proposed: conformational selection favours a particular strain conformation out of a mixture of conformations in a scrapie isolate whilst mutation results in the conformational shift of one conformation into another [51]. Following on from the study in mice [17], it has been subsequently suggested that classical BSE properties that arise in atypical scrapie isolates transmitted to cattle may be due to conformational mutation in a new host [52]. It does not confirm that the atypical scrapie agent is the origin of the classical BSE epidemic and further transmission studies would be required to see whether classical BSE can be generated.
Would PMCA applied to brains from cattle exposed to TSE agents other than classical BSE and atypical scrapie also produce a classical BSE-like molecular phenotype? The PMCA product obtained in the thermostability test using a thermosensitive classical scrapie control showed a profile unlike classical BSE. Atypical BSE has been linked to the origin of classical BSE because of its conversion into classical BSE following serial passages in wild-type mice (L-type BSE [11]) and bovine transgenic mice (H-type BSE [53]). Although we have not tested PMCA products of atypical BSE isolates as part of this study, there is no evidence that PMCA products from atypical BSE convert into classical BSE, at least for H-type BSE using bovine brain as substrate [54]. In fact, we were unable to propagate H-type BSE using the same methodology (S Canoyra, A Marín-Moreno, JM Torres, unpublished observation).
The study results support the decision to maintain the current ban on animal meal in feedstuffs for ruminants, particularly as atypical scrapie occurs world-wide, and eradication is unlikely for a sporadic disease.
In summary, experimental inoculation of cattle with the atypical scrapie agent may produce clinical disease indistinguishable from classical BSE, which cannot be diagnosed by conventional diagnostic tests, but prions can be amplified by ultrasensitive tests in both clinically affected and clinically unremarkable cattle, which reveal classical BSE-like characteristics. Further studies are required to assess whether a BSE-like disease can be confirmed by conventional tests, which may initially include a second passage in cattle.
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Abstract for Prion 2023
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, *
Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
*Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation
Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion
Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
Abstract for Prion 2023
Acknowledgement: TSE unit NCAD, Lethbridge (Jianmin Yang, Sarah Bogart, Rachana Muley, Yuanmu Fang, Keri Colwell, Renee Anderson, John Gray, Rakhi Katoch) (CFIA, Canada), Dr. Catherine Graham (NSDA, Canada), Dr. Michel Levy (UCVM, Canada), Dr. Martin Groschup (FLI, Germany), Dr. Christine Fast (FLI, Germany), Dr. Bob Hills (Health Canada, Canada)
EFSA atypical Scrapie
***> AS is considered more likely (subjective probability range 50–66%) that AS is a non-contagious, rather than a contagious, disease.
SNIP...SEE;
THURSDAY, JULY 8, 2021
EFSA Scientific report on the analysis of the 2‐year compulsory intensified monitoring of atypical scrapie
***> AS is considered more likely (subjective probability range 50–66%) that AS is a non-contagious, rather than a contagious, disease.
***> 2023 PRION CONFERENCE UDATE <***
Price of TSE Prion Poker goes up substantially, all you cattle ranchers and such, better pay close attention here...terry
Transmission of the chronic wasting disease agent from elk to cattle after oronasal exposure
Justin Greenlee, Jifeng Bian, Zoe Lambert, Alexis Frese, and Eric Cassmann Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
Aims: The purpose of this study was to determine the susceptibility of cattle to chronic wasting disease agent from elk.
Materials and Methods: Initial studies were conducted in bovinized mice using inoculum derived from elk with various genotypes at codon 132 (MM, LM, LL). Based upon attack rates, inoculum (10% w/v brain homogenate) from an LM132 elk was selected for transmission studies in cattle. At approximately 2 weeks of age, one wild type steer (EE211) and one steer with the E211K polymorphism (EK211) were fed 1 mL of brain homogenate in a quart of milk replacer while another 1 mL was instilled intranasally. The cattle were examined daily for clinical signs for the duration of the experiment. One steer is still under observation at 71 months post-inoculation (mpi).
Results: Inoculum derived from MM132 elk resulted in similar attack rates and incubation periods in mice expressing wild type or K211 bovine PRNP, 35% at 531 days post inoculation (dpi) and 27% at 448 dpi, respectively. Inoculum from LM132 elk had a slightly higher attack rates in mice: 45% (693 dpi) in wild type cattle PRNP and 33% (468) in K211 mice. Inoculum from LL132 elk resulted in the highest attack rate in wild type bovinized mice (53% at 625 dpi), but no K211 mice were affected at >700 days. At approximately 70 mpi, the EK211 genotype steer developed clinical signs suggestive of prion disease, depression, low head carriage, hypersalivation, and ataxia, and was necropsied. Enzyme immunoassay (IDEXX) was positive in brainstem (OD=4.00, but non-detect in retropharyngeal lymph nodes and palatine tonsil. Immunoreactivity was largely limited to the brainstem, midbrain, and cervical spinal cord with a pattern that was primarily glia-associated.
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection and analysis, decision to publish, or preparation of the manuscript.
"Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material."
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Strain characterization of chronic wasting disease in bovine-PrP transgenic mice
Nuria Jerez-Garrido1, Sara Canoyra1, Natalia Fernández-Borges1, Alba Marín Moreno1, Sylvie L. Benestad2, Olivier Andreoletti3, Gordon Mitchell4, Aru Balachandran4, Juan María Torres1 and Juan Carlos Espinosa1. 1 Centro de Investigación en Sanidad Animal, CISA-INIA-CSIC, Madrid, Spain. 2 Norwegian Veterinary Institute, Ås, Norway. 3 UMR Institut National de la Recherche Agronomique (INRA)/École Nationale Vétérinaire de Toulouse (ENVT), Interactions Hôtes Agents Pathogènes, Toulouse, France. 4 Canadian Food Inspection Agency, Ottawa, Canada.
Aims: Chronic wasting disease (CWD) is an infectious prion disease that affects cervids. Various CWD prion strains have been identified in different cervid species from North America and Europe. The properties of the infectious prion strains are influenced by amino acid changes and polymorphisms in the PrP sequences of different cervid species. This study, aimed to assess the ability of a panel of CWD prion isolates from diverse cervid species from North America and Europe to infect bovine species, as well as to investigate the properties of the prion strains following the adaptation to the bovine-PrP context.
Materials and Methods: BoPrP-Tg110 mice overexpressing the bovine-PrP sequence were inoculated by intracranial route with a panel of CWD prion isolates from both North America (two white-tailed deer and two elk) and Europe (one reindeer, one moose and one red deer).
Results: Our results show distinct behaviours in the transmission of the CWD isolates to the BoPrP-Tg110 mouse model. Some of these isolates did not transmit even after the second passage. Those able to transmit displayed differences in terms of attack rate, survival times, biochemical properties of brain PrPres, and histopathology.
Conclusions: Altogether, these results exhibit the diversity of CWD strains present in the panel of CWD isolates and the ability of at least some CWD isolates to infect bovine species. Cattle being one of the most important farming species, this ability represents a potential threat to both animal and human health, and consequently deserves further study.
Funded by: MCIN/AEI /10.13039/501100011033 and by European Union NextGeneration EU/PRTR
Grant number: PCI2020-120680-2 ICRAD
"Altogether, these results exhibit the diversity of CWD strains present in the panel of CWD isolates and the ability of at least some CWD isolates to infect bovine species. Cattle being one of the most important farming species, this ability represents a potential threat to both animal and human health, and consequently deserves further study."
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Ruminant feed ban for cervids in the United States ?
Posted by flounder on 31 Jan 2015 at 20:14 GMT
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
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In the USA, under the Food and Drug Administration’s BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.
Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
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36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.
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The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
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In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.
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In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible. For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
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Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
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http://webarchive.nationa...
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
Title: Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes
Author
item Cassmann, Eric
item MAMMADOVA, JAJIBA - Orise Fellow
item BENESTAD, SYLVIE - Norwegian Veterinary Institute
item MOORE, SARA JO - Orise Fellow
item Greenlee, Justin
Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2021
Publication Date: 2/11/2021
Citation: Cassmann, E.D., Mammadova, J., Benestad, S., Moore, S., Greenlee, J.J. 2021. Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes. PLoS ONE. 16(2). Article e0246503. https://doi.org/10.1371/journal.pone.0246503.
Interpretive Summary: Atypical scrapie is a prion disease that affects sheep. Unlike classical scrapie, atypical scrapie is thought to occur spontaneously, and it is unlikely to transmit between sheep under natural conditions. Another notable distinction between classical and atypical scrapie is the prion protein genotype of afflicted sheep and the locations in the brain where misfolded prions accumulate. Atypical scrapie generally occurs in sheep that are resistant to classical scrapie. Misfolded prions are predominantly found in the cerebellum for atypical scrapie and not in the brainstem as seen with classical scrapie. Atypical scrapie is a relevant disease because of its potential association with other prion diseases. Some research has shown that the atypical scrapie agent can undergo a transformation of disease forms that makes it appear like classical scrapie or classical bovine spongiform encephalopathy (mad cow disease). Therefore, atypical scrapie is thought to be a possible source for these prion diseases. We investigated the transmission of the atypical scrapie agent to sheep with three different prion protein genotypes. A diagnosis of atypical scrapie was made in all three genotypes of sheep. Misfolded prion protein was detected earliest in the cerebellum and the retina. This is the first report describing the early accumulation of misfolded prions in the retina of sheep with atypical scrapie. Understanding where misfolded prions accumulate in cases of atypical scrapie can lead to better detection earlier in the disease. Furthermore, the materials derived from this experiment will aid in investigating origins of other prion diseases.
Technical Abstract: Scrapie is a transmissible spongiform encephalopathy that occurs in sheep. Atypical/Nor98 scrapie occurs in sheep with that tend to be resistant to classical scrapie and it is thought to occur spontaneously. The purpose of this study was to test the transmission of the Atypical/Nor98 scrapie agent in three genotypes of Suffolk sheep and characterize the distribution of misfolded prion protein (PrPSc). Ten sheep were intracranially inoculated with brain homogenate from a sheep with Atypical/Nor98 scrapie. All sheep with the ARQ/ARQ and ARQ/ARR genotypes developed Atypical/Nor98 scrapie confirmed by immunohistochemistry, and one (1/3) sheep with the VRQ/ARQ genotype had detectable PrPSc consistent with Atypical/Nor98 scrapie at the experimental endpoint of 8 years. Sheep with mild early accumulations of PrPSc in the cerebellum had concomitant retinal PrPSc. Accordingly, large amounts of retinal PrPSc were identified in clinically affected sheep and sheep with dense accumulations of PrPSc in the cerebellum.
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
PRION 2015 CONFERENCE
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 1933-690X
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
FRIDAY, JANUARY 20, 2023
EPIDEMIOLOGY OF SCRAPIE IN THE UNITED STATES
WEDNESDAY, FEBRUARY 03, 2021
Scrapie TSE Prion United States of America a Review February 2021 Singeltary et al
WEDNESDAY, MARCH 16, 2022
SHEEP BY-PRODUCTS AND WHAT ABOUT Scrapie TSE PrP and Potential Zoonosis?
WEDNESDAY, DECEMBER 8, 2021
Importation of Sheep, Goats, and Certain Other Ruminants AGENCY: Animal APHIA, USDA, FINAL RULE [Docket No. APHIS–2009–0095] RIN 0579–AD10
FRIDAY, DECEMBER 10, 2021
USDA APHIS National Scrapie Eradication Program October 2021 Monthly Report Fiscal Year 2022
MONDAY, NOVEMBER 29, 2021
Experimental Oronasal Transmission of Chronic Wasting Disease Agent from White-Tailed Deer to Suffolk Sheep Volume 27, Number 12—December 2021 Dispatch
FRIDAY, DECEMBER 10, 2021
Scrapie at Abattoir: Monitoring, Control, and Differential Diagnosis of Wasting Conditions during Meat Inspection
BSE: TIME TO TAKE HB PARRY SERIOUSLY
HB Parry Seriously’ (YB88/6.8/4.1) IF the scrapie agent is generated from ovine DNA and thence causes disease in other species, then perhaps, bearing in mind the possible role of scrapie in CJD of humans (Davinpour et al, 1985), scrapie and not BSE should be the notifiable disease. https://web.archive.org/web/20030714133556/http://www.bseinquiry.gov.uk/files/yb/1988/06/08004001.pdf
1988: Letter entitled ‘Scrapie, Time to take HB Parry Seriously’ (YB88/6.8/4.1) 24. In this letter I stated that BSE had been officially confirmed as a TSE (when much of the veterinary profession still favoured a variety of alternate hypotheses). I also suggested that scrapie should be made a notifiable disease, and drew attention to the work of HB 'James' Parry and the possibility that natural scrapie in sheep might be of genetic origin. 25. I withdrew the letter following advice from Professor Barlow (who as far as I can recall had been contacted by MAFF and the Veterinary Record) that it might not be in my interests to pursue publication at that moment in time. 26. I received a letter from the then editor, Edward Boden, questioning my permission to release the information that BSE was indeed a proven TSE. I had no permission, though was unaware that any was needed, to inform my profession of this urgent and important fact.
1992: McGill and Wood 27. This paper summarises views as to why an open debate on TSEs and in particular scrapie were and remain essential. We drew attention to the work of Parry, Prusiner and others, and outlined novel explanations for recent research findings in light of such work. We suggested that not all the relevant questions were being asked in the interpretation of data. In particular, the possibility that the infectious agent was being generated de novo from the genome (the PrP gene) in certain families of sheep, was still not being considered, despite a body of scientific data going back over 30 years. It was to be a further 5 years before publications from Government laboratories would start to cite Parry’s work as a possibly correct theory. 28. The refereeing process for this work was at the time not transparent, and I have yet to be informed as to why this remains unpublished.
SNIP...SEE;
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
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The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
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76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC.
Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK
National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health.
2. Determined that pigs naturally exposed to chronic wasting disease (CWD) may act as a reservoir of CWD infectivity. Chronic wasting disease is a naturally occurring, fatal, neurodegenerative disease of cervids. The potential for swine to serve as a host for the agent of CWD disease is unknown. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following experimental oral or intracranial inoculation. Pigs were assigned to 1 of 3 groups: intracranially inoculated; orally inoculated; or non-inoculated. At market weight age, half of the pigs in each group were tested ('market weight' groups). The remaining pigs ('aged' groups) were allowed to incubate for up to 73 months post inoculation (MPI). Tissues collected at necropsy were examined for disease-associated prion protein (PrPSc) by multiple diagnostic methods. Brain samples from selected pigs were bioassayed in mice expressing porcine prion protein. Some pigs from each inoculated group were positive by one or more tests. Bioassay was positive in 4 out of 5 pigs assayed. Although only small amounts of PrPSc were detected using sensitive methods, this study demonstrates that pigs can serve as hosts for CWD. Detection of infectivity in orally inoculated pigs using mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity. Currently, swine rations in the U.S. could contain animal derived components including materials from deer or elk. In addition, feral swine could be exposed to infected carcasses in areas where CWD is present in wildlife populations. The current feed ban in the U.S. is based exclusively on keeping tissues from TSE infected cattle from entering animal feeds. These results indicating the susceptibility of pigs to CWD, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health.
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
LINE TO TAKE
3. If questions on pharmaceuticals are raised at the Press conference, the suggested line to take is as follows:-
"There are no medicinal products licensed for use on the market which make use of UK-derived porcine tissues with which any hypothetical “high risk" ‘might be associated. The results of the recent experimental work at the CSM will be carefully examined by the CSM‘s Working Group on spongiform encephalopathy at its next meeting.
DO Hagger RM 1533 MT Ext 3201
While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.
May I, at the outset, reiterate that we should avoid dissemination of papers relating to this experimental finding to prevent premature release of the information. ...
3. It is particularly important that this information is not passed outside the Department, until Ministers have decided how they wish it to be handled. ...
But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all. ...
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
(x.) There was concern over the exemption for sausage casings/sutures;[13]
Other US BSE risks: the imported products picture 24 Jul 00 Trade Statistics: UK to US Compiled by Terry S.Singeltary Sr of Bacliff, Texas [Opinion (webmaster): The US has focused for years on tracing, containing, and eradicating live animal imports from the UK or other countries with acknowledged BSE like Belgium, including some 499 cattle and the Vermont sheep. This strategy does not acknowledge imports of rendered bovine products from England during the BSE period nor secondary products such as surgical catgut, which is to say surgical cowgut, or dairy cattle embryos, vaccines for veterinarian and human medicines. What has become of these? Mr. Singeltary, who lost his mother to CJD of unexplained origin a few years back and went on to became a well-known TSE activist, has tracked down voluminous pertinent import data through correspondence with UK officials and searches of government web sites. Imports of such products are frequently cited by Europeans in rating BSE risks in the US and in shutting out US exports.
Many people's eyes glaze over when reviewing reams of sometimes older trade statistics. There is no proof that any of the imported products was contaminated with BSE nor if so, any evidence that any BSE product lead to infection in US livestock, surgical patients, or what not. Nonetheless, the data obtained by Mr. Singeltary establish that an appalling variety and tonnage of products that were imported by the US from the UK and othr BSE-affected countries during the peak of the BSE epidemic years.]
10 January 1990 COMMERCIAL IN CONFIDENCE
NOT FOR PUBLICATION
COMMITTEE ON SAFETY OF MEDICINES
WORKING PARTY ON BOVINE SPONGIFORM ENCEPHALOPATHY
SURGICAL CATGUT SUTURES
2.1 At the first meeting of the Working Party on Bovine Spongiform Encephalopathy on 6 September 1989, detailed consideration was given to XXXXX Surgical Catgut. This arose from the Company's response to the Letter to Licence Holders, indicating that the bovine small intestine source material was derived from UK cattle, unlike 8 other licenced catgut sutures. In contrast XXXXX Surgical Catgut was stated to hold over 90% share of the market for catgut sutures, and to constitute approximately 83% of all sutures used in U.K.
IMPORTS OF SUTURES FROM THE KNOWN BSE COUNTRY;
3006.10.0000: STERILE SURGICAL CATGUT, SIMILAR STERILE SUTURE MATERIALS AND STERILETISSUE ADHESIVES FOR SURGICAL WOUND CLOSURE; AND SIMILAR STERILE MATERIAL
U.S. Imports for Consumption: December 1998 and 1998 Year-to-Date
(Customs Value, in Thousands of Dollars) (Units of Quantity: Kilograms)
snip...see;
see original bse inquiry link;
http://www.bseinquiry.gov.uk/files/yb/1990/01/10008001.pdf
updated link 2023...tss
suture concerns;
CATTLE BY-PRODUCTS AND BSE
Small Intestines - Sutures (I thought the source was ovine, but you are checking on this)
CWD TSE PRION CERVID ENVIRONMENTAL RISK FACTORS 2023
