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Exposure of sheep scrapie brain homogenate to rumen‐simulating conditions does not result in a reduction of PrP Sc levels
Author(s) -
Nicholson E.M.,
Richt J.A.,
Rasmussen M.A.,
Hamir A.N.,
LebepeMazur S.,
Horst R.L.
Publication year - 2007
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2007.02124.x
Subject(s) - rumen , scrapie , bovine spongiform encephalopathy , biology , microbiology and biotechnology , physiology , medicine , prion protein , fermentation , food science , disease
Abstract Aims: Experiments were designed to evaluate the potential of rumen‐simulating conditions to reduce PrP Sc levels. Methods and Results: Scrapie‐positive brain material was incubated under rumen‐simulating conditions. Time points were taken over a 24‐h period and PrP Sc levels were analysed by Western blot. No loss of PrP Sc 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.