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SHEEP-PASSAGED BSE EXHIBITS ALTERED PATHOBIO PROPERTIES IN..

flounder

Well-known member
Subject: Sheep-Passaged Bovine Spongiform Encephalopathy Agent Exhibits Altered Pathobiological Properties in Bovine-PrP Transgenic Mice
Date: December 28, 2006 at 8:41 am PST

Journal of Virology, January 2007, p. 835-843, Vol. 81, No. 2
0022-538X/07/$08.00+0 doi:10.1128/JVI.01356-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Sheep-Passaged Bovine Spongiform Encephalopathy Agent Exhibits Altered Pathobiological Properties in Bovine-PrP Transgenic Mice
Juan Carlos Espinosa,1 Olivier Andréoletti,2 Joaquín Castilla,1 María Eugenia Herva,1 Mónica Morales,1 Elia Alamillo,1 Fayna Díaz San-Segundo,1 Caroline Lacroux,2 Séverine Lugan,2 Francisco Javier Salguero,1 Jan Langeveld,3 and Juan María Torres1*
Centro de Investigación en Sanidad Animal, INIA, 28130 Valdeolmos, Madrid, Spain,1 UMR INRA-ENVT 1225, Interactions Hôte Agent Pathogène, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France,2 CIDC-Lelystad, 8203 AA Lelystad, The Netherlands3

Received 27 June 2006/ Accepted 22 October 2006

Sheep can be experimentally infected with bovine spongiform encephalopathy (BSE), and the ensuing disease is similar to scrapie in terms of pathogenesis and clinical signs. BSE infection in sheep is an animal and human health concern. In this study, the transmission in BoPrP-Tg110 mice of prions from BSE-infected sheep was examined and compared to the transmission of original cattle BSE in cattle and sheep scrapie prions. Our results indicate no transmission barrier for sheep BSE prions to infect BoPrP-Tg110 mice, but the course of the disease is accelerated compared to the effects of the original BSE isolate. The shortened incubation period of sheep BSE in the model was conserved in subsequent passage in BoPrP-Tg110 mice, indicating that it is not related to infectious titer differences. Biochemical signature, lesion profile, and PrPSc deposition pattern of both cattle and sheep BSE were similar. In contrast, all three sheep scrapie isolates tested showed an evident transmission barrier and further adaptation in subsequent passage. Taken together, those data indicate that BSE agent can be altered by crossing a species barrier, raising concerns about the virulence of this new prion towards other species, including humans. The BoPrP-Tg110 mouse bioassay should be considered as a valuable tool for discriminating scrapie and BSE in sheep.


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* Corresponding author. Mailing address: Centro de Investigación en Sanidad Animal, INIA, 28130 Valdeolmos, Madrid, Spain. Phone: 34 91 620 23 00. Fax: 34 91 620 22 47. E-mail: [email protected] .

Published ahead of print on 1 November 2006.


http://jvi.asm.org/cgi/content/abstract/81/2/835?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=prion&searchid=1&FIRSTINDEX=0&volume=81&issue=2&resourcetype=HWCIT


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flounder

Well-known member
21 December 2006 - A SEAC Sheep Subgroup Statement

57. The Subgroup agreed that the general conclusions regarding RGS
also apply to the Welsh sheep flock. It concurred that the Welsh
sheep flock is no longer at a disadvantage compared to the rest of
GB with respect to susceptibility to classical scrapie. Thus, there
may no longer be a case for considering Welsh sheep differently
from the rest of the UK. Thus, the current situation is that the risk of
BSE in sheep is likely to be zero, with a consequent reduction in
the perceived risk to public health although there are uncertainties
regarding atypical scrapie.
SEAC Sheep Subgroup
21st December 2006


http://www.seac.gov.uk/statements/sheepsubgrp-statement131006.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.

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://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf


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