title: Second passage of a US scrapie agent in cattle.
abstract: Scrapie and bovine spongiform encephalopathy are similar chronic neurodegenerative diseases of sheep and cattle. An earlier study showed that, on first passage in cattle, a US scrapie agent caused an encephalopathy that was distinct from bovine spongiform encephalopathy (BSE). The present report describes a second passage in cattle, carried out because diseases caused by the spongiform encephalopathy agents often change in character with additional passages in abnormal hosts. For this work, young calves were inoculated intracerebrally with a pooled suspension of brain from cattle that had died of encephalopathy after experimental inoculation with brain from scrapie-affected sheep. The second passage disease was essentially identical with the first passage disease, as judged by clinical signs, histopathological findings and distribution of "prion protein scrapie" (PrPsc). This represents additional evidence to suggest that the US sheep scrapie agent tested is incapable of causing BSE in cattle.
authors.affiliation: United States Department of Agriculture, National Animal Disease Center, Ames, Iowa 50010, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Cutlip
authors.forename: J M
authors.initials: JM
authors.lastname: Miller
authors.forename: H D
authors.initials: HD
authors.lastname: Lehmkuhl
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology / Q000821:virology; D002417:Cattle; D016643:Encephalopathy, Bovine Spongiform / Q000473:pathology / Q000821:virology*; D007150:Immunohistochemistry; D008297:Male; D018620:PrPSc Proteins / Q000472:pathogenicity*; D012608:Scrapie / Q000473:pathology / Q000635:transmission*; D012756:Sheep; D013045:Species Specificity; D014481:United States
chemical_list: D018620:PrPSc Proteins