NR AXAH
AU Nicholson,E.M.; Richt,J.A.; Rasmussen,M.A.; Hamir,A.N.; Lebepe-Mazur,S.; Horst,R.L.
TI Exposure of sheep scrapie brain homogenate to rumen-simulating conditions does not result in a reduction of PrPsc levels
QU Letters in Applied Microbiology 2007 Jun; 44(6): 631-6
PT journal article
AB AIMS: Experiments were designed to evaluate the potential of rumen-simulating conditions to reduce PrPsc levels. METHODS AND RESULTS: Scrapie-positive brain material was incubated under rumen-simulating conditions. Time points were taken over a 24-h period and PrPsc levels were analysed by Western blot. No loss of PrPsc was observed over a 24-h time period. CONCLUSIONS: Our results indicate that a fully developed rumen fermentation does not provide significant protection against prion infection via the oral route. Developmental changes including senescence of immune system function or other developmental changes in the gastrointestinal tract are potential mechanisms by which relative bovine spongiform encephalopathy (BSE) susceptibility might vary with age. SIGNIFICANCE AND IMPACT OF THE STUDY: Epidemiology of the BSE outbreak in the United Kingdom indicates that younger animals were at higher risk of infection. The rumen undergoes pronounced developmental changes early in life, coinciding with the introduction of fibre into the diet. The timeframe of highest risk of infection overlaps the time in life prior to full rumen development. This work indicates that a fully developed rumen does not provide significant protection against prion infection via the oral route of infection. This result implicates other developmental changes that are responsible for the age-dependent susceptibility of cattle to BSE.
IN Nicholson et al. mischten gleich große Proben von PrPsc aus Hirnhomogenat Scrapie-kranker Schafe mit Magensaft einer Kuh und inkubierten die Proben, 0, 1, 2, 4 oder 24 Stunden bei 38°. Danach verglichen sie die PrPsc-Konzentrationen per Western blot und stellten keine Abnahme des PrPsc mit zunehmender Inkubationsdauer fest.
MH Animals; Blotting, Western; *Brain Chemistry; Cattle; Cell Extracts/chemistry; PrPsc Proteins/*analysis/metabolism; Rumen/*chemistry/*microbiology; Scrapie/*immunology; Sheep, Domestic
AD Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA 50010, USA. enicholson@nadc.ars.usda.gov
SP englisch
PO England