L-BSE experimentally transmitted to sheep presents as a unique disease phenotype.
Apart from prion protein genotype, the factors determining the host range and susceptiblity for specific transmissible spongiform encephalopathy agents remain unclear. It is known that bovine atypical L-BSE can transmit to a range of species including primates and humanised transgenic mice. It is important, therefore, that there is as broad an understanding as possible of how such isolates might present in food animal species and how robust they are on inter- and intra-species transmission to inform surveillance sytems and risk assessments. This paper demonstrates that L-BSE can be intracerebrally transmitted to sheep of several genotypes, with the exception of ARR/ARR animals. Positive animals mostly present with a cataplectic form of disease characterized by collapsing episodes and reduced muscle tone. PrP accumulation is confined to the nervous system, with the exception of one animal with lymphoreticular involvement. In Western blot there was maintenance of the low molecular mass and glycoform profile associated with L-BSE, irrespective of ovine host genotype, but there was a substantially higher N-terminal antibody signal relative to the core-specific antibody, which is similar to the ratio associated with classical scrapie. The disease phenotype was maintained on experimental subpassage, but with a shortened survival time indicative of an original species barrier and subsequent adaptation. Passive surveillance approaches would be unlikely to identify such cases as TSE suspects, but current statutory active screening methods would be capable of detecting such cases and classifying them as unusual and requiring further investigation if they were to occur in the field.
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK. marion.simmons@apha.gsi.gov.uk.
Marion M
0000-0003-3870-6079
MM
Simmons
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
Melanie J
MJ
Chaplin
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.|Animal Sciences Unit, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
Timm
T
Konold
Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta Sede Centrale di Torino, via Bologna, 148, 10154, Turin, Italy.
Cristina
C
Casalone
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
Katy E
KE
Beck
Department of Virology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
Leigh
L
Thorne
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
Sharon
S
Everitt
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
Tobias
T
Floyd
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.|Animal Sciences Unit, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
Derek
D
Clifford
Department of Pathology, APHA Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK.
John
J
Spiropoulos
D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D001921:Brain / Q000473:pathology; D002417:Cattle; D016643:Encephalopathy, Bovine Spongiform / Q000175:diagnosis / Q000473:pathology / Q000635:transmission*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D010641:Phenotype; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis / Q000401:mortality / Q000473:pathology / Q000635:transmission*