These transmissible prions believed to be the cause of bovine spongiform encephalopathy (BSE), the technical name for mad cow disease, as well as the human and sheep versions, called Creutzfeldt-Jakob disease and scrapie, respectively are highly resistant to degradation, says Dr. Jason Shih, professor of biotechnology and poultry science at NC State. But the new research, which tested the effects of a bacterial enzyme keratinase on brain tissues from cows with BSE and sheep with scrapie, showed that, when the tissue was pretreated and in the presence of a detergent, the enzyme fully degraded the prion, rendering it undetectable.
The research was published in the Dec. 1 edition of The Journal of Infectious Diseases.
Shih's colleagues in the research study included first author Jan Langeveld, Dick Van de Wiel, Jan Garssen and Alex Bossers from the Central Institute for Animal Disease Control in Lelystad, The Netherlands; and Giles Shih and Jeng-Jie Wang from BioResource International, which is located on NC State's Centennial Campus.
The researchers now plan another study to test the effectiveness of the enzyme on the treated BSE prions in mice. The two-year study begins in January 2004 and is funded with $190,000 from the National Cattleman's Beef Association.
"Our work has been done in vitro, or in test tubes, and we've reduced the prion to undetectable levels," Jason Shih says. "Our work with mice will show whether these undetectable levels of prion are indeed non-infectious."