Recently identified atypical scrapie cases in sheep represent an emerging TSE of which little is known. Incidence in EU countries seems to vary between 3 and 11 per 10,000 tested animals. However, because there is probably a lack of sensitivity in screening tests towards this particular TSE, this value is likely to be an underestimation. There is no consistent information concerning the abnormal PrP or infectivity distribution in peripheral tissues of atypical cases. This absence of data, combined with the involvement of ARR/ARR (genotype most resistant to BSE) animals that were believed to be resistant to TSE, represent a major concern with regards to the efficiency of the current food protection policy against TSE.
This project will establish distribution of abnormal PrP using various tools including Immunohistochemistry, and infectivity (using transgenic mice model) in sheep tissues such as blood, muscle, central nervous system(CNS) and milk. The research will give consideration to the fact that atypical cases could be either a spontaneous affection from CNS origin or an acquired infectious disease resulting from an oral contamination.
- Andréoletti, O., Orge, L., Benestad, S.L., Beringue, V., Litaise, C., Simon, S., Le Dur, A., Laude, H., Simmons, H., Lugan, S., Corbière, F., Costes, P., Morel, N., Schelcher, F. & Lacroux, C. (2011) Atypical/Nor98 scrapie infectivity in sheep peripheral tissues. Published online PLoS Pathogens 7: e1001285