title: The interpretation of disease phenotypes to identify TSE strains following murine bioassay: characterisation of classical scrapie.
abstract: Mouse bioassay can be readily employed for strain typing of naturally occurring transmissible spongiform encephalopathy cases. Classical scrapie strains have been characterised historically based on the established methodology of assessing incubation period of disease and the distribution of disease-specific vacuolation across the brain following strain stabilisation in a given mouse line. More recent research has shown that additional methods could be used to characterise strains and thereby expand the definition of strain "phenotype". Here we present the phenotypic characteristics of classical scrapie strains isolated from 24 UK ovine field cases through the wild-type mouse bioassay. PrPSc immunohistochemistry (IHC), paraffin embedded tissue blots (PET-blot) and Western blotting approaches were used to determine the neuroanatomical distribution and molecular profile of PrPSc associated with each strain, in conjunction with traditional methodologies. Results revealed three strains isolated through each mouse line, including a previously unidentified strain. Moreover IHC and PET-blot methodologies were effective in characterising the strain-associated types and neuroanatomical locations of PrPSc. The use of Western blotting as a parameter to define classical scrapie strains was limited. These data provide a comprehensive description of classical scrapie strain phenotypes on isolation through the mouse bioassay that can provide a reference for further scrapie strain identification.
authors.affiliation: Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey KT15 3NB, United Kingdom. John.Spiropoulos@ahvla.gsi.gov.uk.
authors.forename: Katy E
authors.initials: KE
authors.lastname: Beck
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Vickery
authors.forename: Richard
authors.initials: R
authors.lastname: Lockey
authors.forename: Thomas
authors.initials: T
authors.lastname: Holder
authors.forename: Leigh
authors.initials: L
authors.lastname: Thorne
authors.forename: Linda A
authors.initials: LA
authors.lastname: Terry
authors.forename: Margaret
authors.initials: M
authors.lastname: Denyer
authors.forename: Paul
authors.initials: P
authors.lastname: Webb
authors.forename: Marion M
authors.initials: MM
authors.lastname: Simmons
authors.forename: John
authors.initials: J
authors.lastname: Spiropoulos
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D058889:Molecular Typing / Q000379:methods; D016612:Paraffin Embedding / Q000379:methods; D018620:PrPSc Proteins / Q000145:classification* / Q000235:genetics; D012608:Scrapie / Q000235:genetics / Q000378:metabolism*; D012756:Sheep
chemical_list: D018620:PrPSc Proteins