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One up shot of the mutation to the Beta sheet configuration by the PrPsc protein is that the molecule becomes much more sturdy, and nearly indestructible. Numerous tests have been carried out on infected meat to try and discover some way to destroy the infective agent with a view to creating a cure, or a method of cleaning the meat for consumption, but to no avail. Scientists have tried using chemical disinfectants (including domestic bleach), acids, Ultra violet light, ionising and gamma radiation, potassium permanganate and chlorine dioxide all of which would be mortally toxic to most small animals and bacteria. Also tried were DNAase and RNAase, two substances that are specialised in the breaking down of the different types of nucleic acid, but which had no effect on the TSE agent; this is one of the reasons why many scientists now favour the Prion Theory of a nucleic-acid free infective agent. Various Proteinases were also experimented with, including ones taken from the guts of animals, but these also caused no reduction in the infectivity of the TSE agent.
The only two practices that were found to cause any reduction in TSE infection were the use of strong acid (a 1 molar solution of Sodium Hydroxide), and prolonged heating at very high temperatures (over 18 minutes at above 135 degrees Celsius). Though the infective agent was still present in significant amounts afterwards, even after heating at 360C for 1 hour! Burial in 'wild' soil was even shown to have little effect after 3 years, even though most of the biological matter of the infected sample had decayed away the infective agent remained, almost unchanged. The same happened when samples were incinerated: the sample was reduced to ash, but the agent survived in an infective form none the less.
This nature of indestructibility has grave repercussions for the
disposal of infected meat, for a disease's agent
that does not need to respire or feed and is not totally broken
down by environmental forces or any artificial means can theoretically
survive indefinitely between victims. If this is true then burial
sites of infected carcasses could in future become centres for
reinfection of a herd if the infected soil returned to ground
level and the Prions were consumed
by cattle along with the harmless grass.
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