From: TSS ()
Subject: BSE inoculation to prion diseases-resistant sheep reveals tricky silent carriers
Date: October 21, 2006 at 1:35 pm PST
BSE inoculation to prion diseases-resistant sheep reveals tricky silent carriers
Frédéric Ronzona, 1, Anna Bencsika, 1, Stéphane Lezmia, Johann Vulina, Angeli Kodjob and Thierry Barona, ,
aAgence Française de Sécurité Sanitaire des Aliments (AFSSA), Unité ATNC, 31 avenue Tony Garnier, 69364 LYON cedex 07, France
bEcole Nationale Vétérinaire de Lyon, 1 avenue Bourgelat, 69280 Marcy L’Etoile, France
Received 8 September 2006. Available online 4 October 2006.
The possible transmission of bovine spongiform encephalopathy (BSE) agent to sheep contributed to select genetically sheep considered as resistant to prion diseases i.e., with PrP ARR/ARR genotype. Here, we report the infection of two PrP ARR/ARR genotype sheep using the cattle BSE agent inoculated by peripheral routes. Disease-associated prion protein (PrPd) was detected in the brain for one case (at 2191 days post-infection (dpi)) and only in the nervous enteric system for the other one (at 673 dpi). The electrophoretic pattern of PrPd from the obex region in this BSE challenged sheep was shown to be closer from that found in naturally scrapie-affected sheep with regard to the apparent molecular mass of the unglycosylated PrPd. Importantly, the absence of any clinical symptoms up to 6 years following experimental challenge suggests that silent carriers of the BSE agent may exist among ARR homozygous sheep.
Keywords: Prion; BSE; Scrapie; Sheep; Resistant; Genotype
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1 These authors equally contributed to this work.