NR AXYJ
AU Vulin,J.; Biacabe,A.G.; Arsac,J.N.; Baron,T.G.M.
TI Identification of CH1641-like Isolates in Sheep during the Monitoring for BSE in Small Ruminants in France (2002-2006)
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Natural and Experimental Strains P02.41
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
Since 2002, the surveillance of TSE in small ruminants in the EU has been increased and routinely involved molecular discrimination of scrapie from a possible BSE infection. In this context, we developed a discriminatory BSE-scrapie Western Blot method that has been approved at the EU level. Between 2002 and 2006, 777 sheep were detected as positive for TSE during the active surveillance. 246 (31.7%) were classified as Nor98-like with the confirmatory Western blot. 29 samples (3.7%) could not be characterized. The 502 other samples showed a classical three bands pattern of PrPres (non Nor98-like) and were subsequently tested using our method. In addition, 192 TSE positive and non Nor98-like cases detected in TSE infected flocks were also analysed. Most of the classical isolates (497 (99 %) index cases and 189 (98.4%) from TSE-infected flocks) had PrPres with a higher molecular weight of the unglycosylated PrPres than a cattle BSE control, as well as strong labelling with the N-
terminal P4 antibody. Large variations of the molecular weights (1.2 kDa) were however observed among these samples, although these were consistently higher than the cattle BSE control. On the other hand, we found 5 (1 %) index cases and 3 (1.6 %) cases from TSE-affected flocks presenting patterns with some molecular similarities to ovine BSE (lower molecular weight than the BSE control and low signal with P4). However, with regard to the glycoform profiles, the molecular patterns presented more similarities to the CH1641 experimental isolate, since these samples all displayed lower proportions of the diglycosylated PrPres band. Three of these CH1641-like samples were transmitted to TgOvPrP4 ovine transgenic mice, that confirmed more similarities to CH1641 than to ovine BSE. These data suggest the presence of a(some) scrapie strain(/s) producing unusual PrPres phenotype in sheep, that should be further investigated.
AD J. Vulin, A.-G. Biacabe, J.-N. Arsac, T. Baron, AFSSA (Agence Française de Sécurité Sanitaire des Aliments), France
SP englisch
PO Schottland