title: Atypical scrapie/Nor98 in a sheep from New Zealand.
abstract: In a consignment of sheep brains from New Zealand, to be used in Europe as negative control material in scrapie rapid screening test evaluations, brain samples from 1 sheep (no. 1512) gave the following initially confusing results in various screening tests: the brainstem repeatedly produced negative results in 2 very similar screening kits (enzyme-linked immunosorbent assay [ELISA]-1, ELISA-2), a macerate made from brainstem and cerebellum returned a clearly positive result in ELISA-2, and the macerate and a brainstem sample gave negative results in a third screening test (ELISA-3). In subsequent testing, cerebellum tissue alone tested strongly positive in ELISA-1 and produced a banding pattern very similar to atypical scrapie/Nor98 in a confirmatory Western blot (WB). The macerate showed weak staining in the confirmatory WB but presented a staining pattern identical to atypical scrapie/Nor98 in the scrapie-associated fibril WB. The latter test confirmed conclusively the first case of atypical scrapie/Nor98 in a sheep from New Zealand. Other parts of the brain either tested negative or very weak positive in ELISA-2 and in WBs, or tested with negative results by histopathology and immunohistochemistry. It appears that sheep no. 1512 is a case of atypical scrapie/Nor98 in which the abnormal prion protein was detected mainly in the cerebellum. This case emphasizes the need to retain brainstem, and cerebral and cerebellar tissues, as frozen and fixed materials, for conclusive confirmatory testing. Furthermore, consideration should be given to which screening method to use.
authors.affiliation: Investigation and Diagnostic Centre Wallaceville, Biosecurity New Zealand, Ministry of Agriculture and Forestry, PO Box 40742, Upper Hutt 5140, New Zealand. Reinhold.Kittelberger@maf.govt.nz
authors.forename: Reinhold
authors.initials: R
authors.lastname: Kittelberger
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Chaplin
authors.forename: Marion M
authors.initials: MM
authors.lastname: Simmons
authors.forename: Ana
authors.initials: A
authors.lastname: Ramirez-Villaescusa
authors.forename: Lachlan
authors.initials: L
authors.lastname: McIntyre
authors.forename: Stuart C
authors.initials: SC
authors.lastname: MacDiarmid
authors.forename: Michaela J
authors.initials: MJ
authors.lastname: Hannah
authors.forename: Judy
authors.initials: J
authors.lastname: Jenner
authors.forename: Rudolfo
authors.initials: R
authors.lastname: Bueno
authors.forename: Daniele
authors.initials: D
authors.lastname: Bayliss
authors.forename: Hugh
authors.initials: H
authors.lastname: Black
authors.forename: Clive J
authors.initials: CJ
authors.lastname: Pigott
authors.forename: Joseph S
authors.initials: JS
authors.lastname: O'Keefe
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005060:Europe; D009520:New Zealand / Q000453:epidemiology; D012608:Scrapie / Q000145:classification* / Q000453:epidemiology; D012756:Sheep