title: Progression of prion infectivity in asymptomatic cattle after oral bovine spongiform encephalopathy challenge.
abstract: The presence of BSE prion infectivity in asymptomatic cattle and its tissue distribution are important concerns for both human and veterinary health and food safety. In this work, a collection of tissues from asymptomatic cattle challenged orally with BSE and culled at 20, 24, 27, 30 and 33 months have been used to inoculate intracerebrally BoPrP-Tg110 mice expressing bovine PrP to assess their infectivity. Results demonstrate that BSE infectivity in asymptomatic cattle is essentially restricted to the nervous system, Peyer's patches and tonsils, as reported previously for terminally BSE-diseased cattle. BSE infectivity was detectable in Peyer's patches and tonsils at all time points analysed, but infectivity in nervous tissues (brainstem and sciatic nerve) was only detectable after 27 months from inoculation. Infectivity in brainstem increased markedly at 33 months after inoculation. All other investigated tissues or fluids (spleen, skeletal muscle, blood and urine) revealed no detectable infectivity throughout the time course studied.
authors: Centro de Investigación en Sanidad (CISA-INIA), Valdeolmos, Madrid, Spain.
authors: Juan Carlos
authors: JC
authors: Espinosa
authors: Centro de Investigación en Sanidad (CISA-INIA), Valdeolmos, Madrid, Spain.
authors: Mónica
authors: M
authors: Morales
authors: Centro de Investigación en Sanidad (CISA-INIA), Valdeolmos, Madrid, Spain.
authors: Joaquín
authors: J
authors: Castilla
authors: School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors: Mark
authors: M
authors: Rogers
authors: Centro de Investigación en Sanidad (CISA-INIA), Valdeolmos, Madrid, Spain.
authors: Juan María
authors: JM
authors: Torres
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001933:Brain Stem / Q000737:chemistry; D002417:Cattle; D016643:Encephalopathy, Bovine Spongiform / Q000378:metabolism / Q000635:transmission*; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D014066:Palatine Tonsil / Q000737:chemistry; D010581:Peyer's Patches / Q000737:chemistry; D011328:Prions / Q000032:analysis; D012584:Sciatic Nerve / Q000737:chemistry; D013997:Time Factors
chemical_list: D011328:Prions