- What are prions?
• Answer: One might think that processed meat and bone meal from sheep or cows could not carry any kind of serious infection.
After all, carcasses are boiled as part of the process of “rendering” that ultimately converts the dead animals into feed for living creatures.
It is true that the high temperatures typical in that rendering process would be sufficient to kill most disease-bearing organisms.
However, the type of infectious agent that is responsible for BSE is very unusual. Unlike most illnesses that are caused by bacteria or viruses, BSE is caused by something called a prion (pronounced “pree-on”).
Prions are very resilient proteins that are particularly worrisome because they are resistant to most forms of disinfection.
They retain their infectivity even after normal sterilization procedures such as those using heat and ionizing radiation.
In fact, prions are not even destroyed by temperatures well above the boiling point.
In a laboratory test of the scrapie prion, some infectivity still remained after a full hour of exposure to dry heat at 680 degrees Farenheit. (360 degrees Celsius.).
Prions are also impervious to freezing and drying.
Much of the reason for their hardiness is no doubt related to their unusual composition.
Prions have no genetic material and consist entirely of protein.
They are composed of a complex combination of thousands of amino acids.
Since some sterilization processes—like ionizing radiation—work by destroying an organism’s genetic material, prions can not be harmed by these measures.
Source: Proof positive