title: Identification and characterization of two bovine spongiform encephalopathy cases diagnosed in the United States.
abstract: Bovine spongiform encephalopathy (BSE) is a transmissible spongiform encephalopathy of cattle, first detected in 1986 in the United Kingdom and subsequently in other countries. It is the most likely cause of variant Creutzfeldt-Jakob disease (vCJD) in humans, but the origin of BSE has not been elucidated so far. This report describes the identification and characterization of two cases of BSE diagnosed in the United States. Case 1 (December 2003) exhibited spongiform changes in the obex area of the brainstem and the presence of the abnormal form of the prion protein, PrP(Sc), in the same brain area, by immunohistochemistry (IHC) and Western blot analysis. Initial suspect diagnosis of BSE for case 2 (November 2004) was made by a rapid ELISA-based BSE test. Case 2 did not exhibit unambiguous spongiform changes in the obex area, but PrP(Sc) was detected by IHC and enrichment Western blot analysis in the obex. Using Western blot analysis, PrP(Sc) from case 1 showed molecular features similar to typical BSE isolates, whereas PrP(Sc) from case 2 revealed an unusual molecular PrP(Sc) pattern: molecular mass of the unglycosylated and monoglycosylated isoform was higher than that of typical BSE isolates and case 2 was strongly labeled with antibody P4, which is consistent with a higher molecular mass. Sequencing of the prion protein gene of both BSE-positive animals revealed that the sequences of both animals were within [corrected] the range of the prion protein gene sequence diversity previously reported for cattle.
authors.affiliation: Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, Iowa 50010, USA. jricht@nadc.ars.usda.gov
authors.forename: Jürgen A
authors.initials: JA
authors.lastname: Richt
authors.forename: Robert A
authors.initials: RA
authors.lastname: Kunkle
authors.forename: David
authors.initials: D
authors.lastname: Alt
authors.forename: Eric M
authors.initials: EM
authors.lastname: Nicholson
authors.forename: Amir N
authors.initials: AN
authors.lastname: Hamir
authors.forename: Stefanie
authors.initials: S
authors.lastname: Czub
authors.forename: John
authors.initials: J
authors.lastname: Kluge
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Davis
authors.forename: S Mark
authors.initials: SM
authors.lastname: Hall
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000473:pathology*; D002417:Cattle; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D016643:Encephalopathy, Bovine Spongiform / Q000175:diagnosis* / Q000473:pathology; D006041:Goats; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011328:Prions / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep; D014481:United States
chemical_list: D011328:Prions; D004247:DNA