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BOVINE SPONGIFORM ENCEPHALOPATHY AND SCRAPIE ISOLATION AND IDENTIFICATION OF THE INFECTIVE AGENT

Objective

Bovine Spongiform Encephalopathy (BSE) is a new bovine disease first identified in November 1986 in U.K. where it developped as an extented common source epidemic (more than 40.000 cumulated confirmated cases at the end of 1991) Sporadic cases has been recognized in two others Member states: Ireland and France. It belongs to a very specific group of diseases: the Transmissible Sub-Acute Spongiform Encephalopahtie (TSSE's)

Scrapie is another TSSE's naturally occuring for more than 200 years in ovine and caprine species. It occurs in many Members states.

The precise nature of the infective agent associated with TSSE's is still not completely known.

The eventual objective of the project is to establish a diagnostic procedure for confirming BSE in clinical live suspected animals, because at present, confirmation is only possible by microscopic examination of the brain post mortem. This diagnostic procedure could also applied to the identification of preclinical BSE in live animals.

The immediate objectives are to study and try to identify precisely the nature of the infective agents of BSE ans scrapic to achieve the diagnostic objective mentioned above. A suitable diagnostic procedure would allow a much more earlier and rapide recognition of disease andwill allow a much more efficient control and eradiction.
Bovine spongiform encephalopathy (BSE) is a new bovine disease first identified in November 1986 in the UK where it developed as an extended common source epidemic with more than 80000 confirmed cases up to the end of 1992. This study is to identify the nature of the infective agents of BSE and scrapie and to establish a diagnostic procedure for confirming BSE inlive suspect animals.

One participating laboratory is producing BSE infected mouse (homozygous since p7 allele) brain material. Some material will be used for the purification of prion protein SC (PrP) and the hypothetical infectious agent while other material will be used for the preparation of test material for the assay of diagnostic reagents. This laboratory has already tested BSE positive cow brain with good results, particularly with an antibody to sheep specific PrP peptide supplied by another participating laboratory. This second laboratory has prepared various polyclonal antisera against peptide sequence of amyloid fibril from BSE and scrapie (sheep, mouse and hamster scrapie) with promising results. A new purification of protocol has been designed with the scrapie hamster model.
Material obtained from the UK/BSE infected material and scrapie infected material from member states will be used to test the following hypothesis : the infective agent of Transmissible Sub-acute Spongiform Encephalopathies (TSSE's) has an independant nucleic acid genome in complex with PrP (Prion Protein).

Purified PrP will be tested as an affinity ligand to isolate scrapic specific nucleic acids either by mixing with purified nucleic acides from scrapie affected mouse brain or by attaching to a column matrix. Any nucleic acids isolated using such procedures will be cloned and characterised using standard techniques and comparisons will be made with normal brain.

Any nucleic acids isolated by these novel approaches to be used would not necessarily be infective, but it is nonetheless hope that they may be useful for diagnostic purposes.

Coordinator

Centre National d'Études Vétérinaries et Alimentaires (CNEVA)
Address
31 Avenue Tony Garnier
69342 Lyon
France

Participants (5)

Dr J. Van Bekkum
Netherlands
Address
Wildban 8
8222AG Lelystad
Foundation for Research and Technology
Greece
Address
Heraklion 1527
71110 Crete
INSTITUTE FOR ANIMAL HEALTH
United Kingdom
Address
High Street,compton
RG20 7NN Newbury
Institut National de la Recherche Agronomique (INRA)
France
Address
Domaine De Vilvert
78352 Jouy-en-josas
ROBERT KOCH-INSTITUT
Germany
Address
Nordufer 20
13353 Berlin