title: BSE inoculation to prion diseases-resistant sheep reveals tricky silent carriers.
abstract: 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 (PrP(d)) 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 673dpi). The electrophoretic pattern of PrP(d) 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 PrP(d). 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.
authors.affiliation: Agence Française de Sécurité Sanitaire des Aliments (AFSSA), Unité ATNC, 31 avenue Tony Garnier, 69364 LYON cedex 07, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ronzon
authors.forename: Anna
authors.initials: A
authors.lastname: Bencsik
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lezmi
authors.forename: Johann
authors.initials: J
authors.lastname: Vulin
authors.forename: Angeli
authors.initials: A
authors.lastname: Kodjo
authors.forename: Thierry
authors.initials: T
authors.lastname: Baron
mesh_terms: D000818:Animals; D002417:Cattle; D016643:Encephalopathy, Bovine Spongiform / Q000235:genetics* / Q000517:prevention & control* / Q000635:transmission; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006579:Heterozygote; D011328:Prions / Q000235:genetics*; D012756:Sheep; D012757:Sheep Diseases / Q000235:genetics* / Q000517:prevention & control* / Q000635:transmission
chemical_list: D011328:Prions