Lesion profiling at primary isolation in RIII mice is insufficient in distinguishing BSE from classical scrapie.
Primary isolation of bovine spongiform encephalopathy (BSE) in RIII mice generates a lesion profile believed to be reproducible and distinct from that produced by classical scrapie. This profile, which is characterized by peaks at gray matter areas 1, 4 and 7 (dorsal medulla, hypothalamus and septal nuclei), is used to diagnose BSE on primary isolation. The aim of this study was to investigate whether the BSE agent could be present in sheep diagnosed with classical scrapie, using lesion profiles in RIII mice as a discriminatory method. Sixty-two positive scrapie field cases were collected from individual farms between 1996 and 1999 and bioassayed in RIII mice. Fifty-five of these isolates transmitted successfully to at least one mouse. Of the 31 that produced adequate data to allow lesion profile analysis, 10 showed a consistent profile with peaks at brain areas 1, 4 and 7. All inocula for this subgroup were derived from sheep of genotype ARQ/ARQ. While the 1-4-7-scrapie profile exhibited similarities to BSE in RIII mice at primary isolation, it was distinguishable based on histopathology, immunohistochemistry and cluster analysis. We conclude that caution should be taken to distinguish this profile from BSE and that additional parameters should be considered to reach a final diagnosis.
Beck
Katy E
KE
Veterinary Laboratories Agency-Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK.
Chaplin
Melanie
M
Stack
Michael
M
Sallis
Rosemary E
RE
Simonini
Sarah
S
Lockey
Richard
R
Spiropoulos
John
J
D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D001923:Brain Chemistry; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000473:pathology; D016000:Cluster Analysis; D003937:Diagnosis, Differential; D016643:Encephalopathy, Bovine Spongiform / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*; D007150:Immunohistochemistry; D051379:Mice; D036421:Nerve Fibers, Unmyelinated / Q000737:chemistry / Q000473:pathology; D018620:PrPSc Proteins / Q000032:analysis* / Q000302:isolation & purification; D012608:Scrapie / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D016019:Survival Analysis
D018620:PrPSc Proteins