Sparse PrP-Sc accumulation in the placentas of goats with naturally acquired scrapie
Sparse PrP-Sc accumulation in the placentas of goats with naturally acquired scrapie
Katherine I O'Rourke , Dongyue Zhuang , Thomas C Truscott , Huijan Yan and David A Schneider
BMC Veterinary Research 2011, 7:7doi:10.1186/1746-6148-7-7
Published: 1 February 2011
Abstract (provisional)
Background
Domestic goats (Capra hircus) are a natural and experimental host of scrapie and bovine spongiform encephalopathy, the transmissible spongiform encephalopathies (TSE) of sheep and cattle. Goats are also reported to be susceptible to experimental infection with the agents of TSEs of deer and elk (chronic wasting disease) and humans (Creutzfeldt Jakob disease). Distribution of PrPsc, the abnormal prion protein, is similar in the tissues of sheep and goats but no data are available on the potential shedding of the agent through the placenta, the presumed route of transmission of ovine scrapie. We describe PrPSc accumulation in the placenta of goats with naturally acquired classical scrapie in comparison to field cases of classical ovine scrapie.
Results
This study demonstrated that in a small sample of U.S. goats with scrapie, only one animal shed a placenta with PrPSc levels similar to those seen in sheep with classical scrapie, although distribution of PrPSc in the intact placentomes was similar. Neither genotype nor disease stage could account for the generally low levels of PrPSc in most of the caprine placentas.
Conclusions
Some regulatory control measures are based on the finding that ovine scrapie is transmitted through contact with placentas from infected sheep. In this study, domestic goats with naturally acquired scrapie typically showed sparse accumulation of PrPSc in shed placentas. If caprine scrapie is transmitted in the absence of detectable placental prions, assessment of addition sources of the agent may be warranted.
snip...
Conclusions In this study, PrPSc was detected in some but not all placentomes from naturally infected goats using a sensitive western blot assay. PrPSc detectable by IHC was sparsely distributed in caprine cotyledons and ELISA values were lower than observed with most ovine cotyledons. In spite of the poorly defined effects of PRNP genetics, scrapie strain, dose, route and source of infection, the caprine placenta may represent a source of infection to progeny and herd mates as well as a source of persistent environmental contamination. Caprine scrapie is rarely reported in the US and additional studies using experimentally infected goats may be useful in determining the role of the placenta in transmission of caprine scrapie.
http://www.biomedcentral.com/1746-6148/7/7/abstract
http://www.biomedcentral.com/content/pdf/1746-6148-7-7.pdf
>>> In spite of the poorly defined effects of PRNP genetics, scrapie strain, dose, route and source of infection, the caprine placenta may represent a source of infection to progeny and herd mates as well as a source of persistent environmental contamination. <<<
Could this route of infection be the cause of the many cases of Goat scrapie from the same herd in Michigan USA ?
Has this been investigated ?
(Figure 6) including five goat cases in FY 2008 that originated from the same herd in Michigan. This is highly unusual for goats, and I strenuously urge that there should be an independent investigation into finding the common denominator for these 5 goats in the same herd in Michigan with Scrapie. ...
Kind Regards, Terry
Scrapie Nor-98 like case in California FY 2011 AS of December 31, 2010.
Scrapie cases in goats FY 2002 - 2011 AS of December 31, 2010 Total goat cases = 21 Scrapie cases, 0 Nor-98 like Scrapie cases (21 field cases, 0 RSSS cases)
Last herd with infected goats disignated in FY 2008 Michigan 8 cases
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
UPDATED RESPONSE ON MY CONCERNS OF GOAT SCRAPIE IN MICHIGAN ;
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Dear Mr Singeltary,
Thank you for submitting your comment on BMC Veterinary Research article (2011, 7:7). We have read your comment with interest but we feel that only the authors of the article can answer your question about further investigation of the route of infection of the five goats in Michigan. We advise that you contact the authors directly rather than post a comment on the article.
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Thursday, January 07, 2010
Scrapie and Nor-98 Scrapie November 2009 Monthly Report Fiscal Year 2010 and FISCAL YEAR 2008
http://scrapie-usa.blogspot.com/2010/01/scrapie-and-nor-98-scrapie-november.html
In FY 2010, 72 cases of classical Scrapie and 5 cases of Nor-98 like Scrapie were confirmed...
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/yearly_report.ppsx
Scrapie Nor-98 like case in California FY 2011 AS of December 31, 2010.
Scrapie cases in goats FY 2002 - 2011 AS of December 31, 2010 Total goat cases = 21 Scrapie cases, 0 Nor-98 like Scrapie cases (21 field cases, 0 RSSS cases)
Last herd with infected goats disignated in FY 2008 Michigan 8 cases
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
Thursday, November 18, 2010
Increased susceptibility of human-PrP transgenic mice to bovine spongiform encephalopathy following passage in sheep
http://bse-atypical.blogspot.com/2010/11/increased-susceptibility-of-human-prp.html
Sunday, October 3, 2010
Scrapie, Nor-98 atypical Scrapie, and BSE in sheep and goats North America, who's looking ?
http://nor-98.blogspot.com/2010/10/scrapie-nor-98-atypical-scrapie-and-bse.html
http://nor-98.blogspot.com/
Sunday, December 12, 2010
EFSA reviews BSE/TSE infectivity in small ruminant tissues News Story 2 December 2010
http://transmissiblespongiformencephalopathy.blogspot.com/2010/12/efsa-reviews-bsetse-infectivity-in.html
Monday, November 22, 2010
Atypical transmissible spongiform encephalopathies in ruminants: a challenge for disease surveillance and control
REVIEW ARTICLES
http://transmissiblespongiformencephalopathy.blogspot.com/2010/11/atypical-transmissible-spongiform.html
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
http://scrapie-usa.blogspot.com/2010/04/scrapie-and-atypical-scrapie.html
Wednesday, January 19, 2011
EFSA and ECDC review scientific evidence on possible links between TSEs in animals and humans Webnachricht 19 Januar 2011
http://transmissiblespongiformencephalopathy.blogspot.com/2011/01/efsa-and-ecdc-review-scientific.html
Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518
Post a comment on this article Sparse PrP-Sc accumulation in the placentas of goats with naturally acquired scrapie Katherine I O'Rourke , Dongyue Zhuang , Thomas C Truscott , Huijan Yan and David A Schneider
BMC Veterinary Research 2011, 7:7doi:10.1186/1746-6148-7-7
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(Figure 6) including five goat cases in FY 2008 that originated from the same herd in Michigan. This is highly unusual for goats, and I strenuously urge that there should be an independent investigation into finding the common denominator for these 5 goats in the same herd in Michigan with Scrapie. ...
Kind Regards, Terry
Thursday, January 07, 2010
Scrapie and Nor-98 Scrapie November 2009 Monthly Report Fiscal Year 2010 and FISCAL YEAR 2008
http://scrapie-usa.blogspot.com/2010/01/scrapie-and-nor-98-scrapie-november.html
In FY 2010, 72 cases of classical Scrapie and 5 cases of Nor-98 like Scrapie were confirmed...
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/yearly_report.ppsx
Scrapie Nor-98 like case in California FY 2011 AS of December 31, 2010.
Scrapie cases in goats FY 2002 - 2011 AS of December 31, 2010 Total goat cases = 21 Scrapie cases, 0 Nor-98 like Scrapie cases (21 field cases, 0 RSSS cases)
Last herd with infected goats disignated in FY 2008 Michigan 8 cases
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
Thursday, November 18, 2010
Increased susceptibility of human-PrP transgenic mice to bovine spongiform encephalopathy following passage in sheep
http://bse-atypical.blogspot.com/2010/11/increased-susceptibility-of-human-prp.html
Sunday, October 3, 2010
Scrapie, Nor-98 atypical Scrapie, and BSE in sheep and goats North America, who's looking ?
http://nor-98.blogspot.com/2010/10/scrapie-nor-98-atypical-scrapie-and-bse.html
http://nor-98.blogspot.com/
Sunday, December 12, 2010
EFSA reviews BSE/TSE infectivity in small ruminant tissues News Story 2 December 2010
http://transmissiblespongiformencephalopathy.blogspot.com/2010/12/efsa-reviews-bsetse-infectivity-in.html
BSE has been detected in two goats. One case was a French goat which was born in 2000 and died in 2002. The second was a British goat which was born in 1987 and died in 1990.
http://www.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/bse/othertses/scrapie/
http://www.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/bse/science-research/sheep-goats/experimental.htm
http://www.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/bse/science-research/projects-table.htm#3d
http://www.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/bse/science-research/documents/bse-sheep-goats.pdf
One of these isolates (TR316211) behaved like the CH1641 isolate, with PrPres features in mice similar to those in the sheep brain. From two other isolates (O100 and O104), two distinct PrPres phenotypes were identified in mouse brains, with either high (h-type) or low (l-type) apparent molecular masses of unglycosylated PrPres, the latter being similar to that observed with CH1641, TR316211, or BSE. Both phenotypes could be found in variable proportions in the brains of the individual mice. In contrast with BSE, l-type PrPres from "CH1641-like" isolates showed lower levels of diglycosylated PrPres. From one of these cases (O104), a second passage in mice was performed for two mice with distinct PrPres profiles. This showed a partial selection of the l-type phenotype in mice infected with a mouse brain with predominant l-type PrPres, and it was accompanied by a significant increase in the proportions of the diglycosylated band. These results are discussed in relation to the diversity of scrapie and BSE strains.
http://jvi.asm.org/cgi/content/full/81/13/7230?view=long&pmid=17442721
In the US, scrapie is reported primarily in sheep homozygous for 136A/171Q (AAQQ) and the disease phenotype is similar to that seen with experimental strain CH1641.
http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=182469
4.2.9 A further hypothesis to explain the occurrence of BSE is the emergence or selection of a strain or strains of the scrapie agent pathogenic for cattle. Mutations of the scrapie agent. which can occur after a single passage in mice. have been well documented (9). This phenomenon cannot be dismissed for BSE. but given the form of the epidemic and the geographically widespread occurrence of BSE, such a hypothesis" would require the emergence of a mutant scrapie strain simultaneously in a large . number of sheep flocks, or cattle. throughout the country. Also. if it resulted "from a localised chance transmission of the scrapie strain from sheep to cattle giving rise , . to a mutant. a different pattern of disease would have been expected: its range would '. have increased with time. Thus the evidence from Britain is against the disease being due to a new strain of the agent, but we note that in the United States from 1984 to 1988 outbreaks of scrapie in sheep flocks are reported to have Increased markedly. now being nearly 3 times as high as during any previous period (18).
http://collections.europarchive.org/tna/20080102132706/http://www.bseinquiry.gov.uk/files/ib/ibd1/tab02.pdf
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. ...
http://collections.europarchive.org/tna/20090505194948/http://bseinquiry.gov.uk/files/yb/1988/06/08004001.pdf
http://scrapie-usa.blogspot.com/2007/12/scrapie-hb-parry-seriously-yb886841.html
EVIDENCE OF SCRAPIE IN SHEEP AS A RESULT OF FOOD BORNE EXPOSURE
This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........
http://web.archive.org/web/20010305222246/www.bseinquiry.gov.uk/files/yb/1994/02/07002001.pdf
RISK OF BSE TO SHEEP VIA FEED
http://collections.europarchive.org/tna/20090114022605/http://www.bseinquiry.gov.uk/files/sc/seac31/tab01.pdf
Marion Simmons communicated surprising evidence for oral transmissibility of Nor98/atypical scrapie in neonatal sheep and although bioassay is ongoing, infectivity of the distal ileum of 12 and 24 month infected sheep is positive in Tg338 mice.
http://www.goatbse.eu/site/index.php?option=com_content&view=article&id=94:minutes-workshop-2010&catid=9:popular&Itemid=22
SUMMARY REPORTS OF MAFF BSE TRANSMISSION STUDIES AT THE CVL ;
http://collections.europarchive.org/tna/20090114023010/http://www.bseinquiry.gov.uk/files/sc/seac18/tab02b.pdf
THE RISK TO HUMANS FROM SHEEP;
http://collections.europarchive.org/tna/20090114022915/http://www.bseinquiry.gov.uk/files/sc/seac24/tab03.pdf
EXPERIMENTAL TRANSMISSION OF BSE TO SHEEP
http://collections.europarchive.org/tna/20090114023211/http://www.bseinquiry.gov.uk/files/sc/seac25/tab05.pdf
SHEEP AND BSE
PERSONAL AND CONFIDENTIAL
SHEEP AND BSE
A. The experimental transmission of BSE to sheep.
Studies have shown that the ''negative'' line NPU flock of Cheviots can be experimentally infected with BSE by intracerebral (ic) or oral challenge (the latter being equivalent to 0.5 gram of a pool of four cow brains from animals confirmed to have BSE).
http://collections.europarchive.org/tna/20090506010048/http://www.bseinquiry.gov.uk/files/sc/seac33/tab02.pdf
RB264
BSE - TRANSMISSION STUDIES
http://collections.europarchive.org/tna/20090113230127/http://www.bseinquiry.gov.uk/files/sc/Seac06/tab06.pdf
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.
snip...
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
12/10/76 AGRICULTURAL RESEARCH COUNCIL REPORT OF THE ADVISORY COMMITTE ON SCRAPIE Office Note CHAIRMAN: PROFESSOR PETER WILDY
snip...
A The Present Position with respect to Scrapie A] The Problem Scrapie is a natural disease of sheep and goats. It is a slow and inexorably progressive degenerative disorder of the nervous system and it ia fatal. It is enzootic in the United Kingdom but not in all countries. The field problem has been reviewed by a MAFF working group (ARC 35/77). It is difficult to assess the incidence in Britain for a variety of reasons but the disease causes serious financial loss; it is estimated that it cost Swaledale breeders alone $l.7 M during the five years 1971-1975. A further inestimable loss arises from the closure of certain export markets, in particular those of the United States, to British sheep. It is clear that scrapie in sheep is important commercially and for that reason alone effective measures to control it should be devised as quickly as possible. 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.
snip...
76/10.12/4.6
http://web.archive.org/web/20010305223125/www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
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).
http://www.nature.com/nature/journal/v236/n5341/abs/236073a0.html
Epidemiology of Scrapie in the United States 1977
http://web.archive.org/web/20030513212324/http://www.bseinquiry.gov.uk/files/mb/m08b/tab64.pdf
One of these isolates (TR316211) behaved like the CH1641 isolate, with PrPres features in mice similar to those in the sheep brain. From two other isolates (O100 and O104), two distinct PrPres phenotypes were identified in mouse brains, with either high (h-type) or low (l-type) apparent molecular masses of unglycosylated PrPres, the latter being similar to that observed with CH1641, TR316211, or BSE. Both phenotypes could be found in variable proportions in the brains of the individual mice. In contrast with BSE, l-type PrPres from "CH1641-like" isolates showed lower levels of diglycosylated PrPres. From one of these cases (O104), a second passage in mice was performed for two mice with distinct PrPres profiles. This showed a partial selection of the l-type phenotype in mice infected with a mouse brain with predominant l-type PrPres, and it was accompanied by a significant increase in the proportions of the diglycosylated band. These results are discussed in relation to the diversity of scrapie and BSE strains.
http://jvi.asm.org/cgi/content/full/81/13/7230?view=long&pmid=17442721
In the US, scrapie is reported primarily in sheep homozygous for 136A/171Q (AAQQ) and the disease phenotype is similar to that seen with experimental strain CH1641.
http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=182469
Monday, November 22, 2010
Atypical transmissible spongiform encephalopathies in ruminants: a challenge for disease surveillance and control
REVIEW ARTICLES
http://transmissiblespongiformencephalopathy.blogspot.com/2010/11/atypical-transmissible-spongiform.html
P03.141
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute,
Norway Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
PR-26
NOR98 SHOWS MOLECULAR FEATURES REMINISCENT OF GSS
R. Nonno1, E. Esposito1, G. Vaccari1, E. Bandino2, M. Conte1, B. Chiappini1, S. Marcon1, M. Di Bari1, S.L. Benestad3, U. Agrimi1 1 Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Rome, Italy (romolo.nonno@iss.it); 2 Istituto Zooprofilattico della Sardegna, Sassari, Italy; 3 National Veterinary Institute, Department of Pathology, Oslo, Norway
Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
119
http://www.neuroprion.com/pdf_docs/conferences/prion2006/abstract_book.pdf
A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes
Annick Le Dur*,?, Vincent Béringue*,?, Olivier Andréoletti?, Fabienne Reine*, Thanh Lan Laï*, Thierry Baron§, Bjørn Bratberg¶, Jean-Luc Vilotte?, Pierre Sarradin**, Sylvie L. Benestad¶, and Hubert Laude*,?? +Author Affiliations
*Virologie Immunologie Moléculaires and ?Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; ?Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; §Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
***Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)
Abstract Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. *** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
http://www.pnas.org/content/102/44/16031.abstract
WHAT I perceive to be political junk science and regulations there from, by exempting the atypical NOR-98 scrapie from TSE regulations strictly by _assumption_, before transmission studies to assure that transmission cannot accure. This was like putting the cart before the horse, and risk human and animal health around the globe due to this stupid policy.
Monday, November 30, 2009
USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE
http://nor-98.blogspot.com/2009/11/usda-and-oie-collaborate-to-exclude.html
Sunday, March 28, 2010
Nor-98 atypical Scrapie, atypical BSE, spontaneous TSE, trade policy, sound science ?
http://nor-98.blogspot.com/2010/03/nor-98-atypical-scrapie-atypical-bse.html
Monday, November 22, 2010
SHEEP WITH MASTITIS TRANSMIT INFECTIOUS PRIONS THROUGH THE MILK
http://scrapie-usa.blogspot.com/2010/11/sheep-with-mastitis-transmit-infectious.html
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
http://scrapie-usa.blogspot.com/2010/04/scrapie-and-atypical-scrapie.html
Wednesday, January 19, 2011
EFSA and ECDC review scientific evidence on possible links between TSEs in animals and humans Webnachricht 19 Januar 2011
http://transmissiblespongiformencephalopathy.blogspot.com/2011/01/efsa-and-ecdc-review-scientific.html
TSS
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