Saw this on the RB board.
Ozone sterilization shows potential for prion inactivation
by Bryan Salvage on 5/2/02 for www.meatingplace.com
Preliminary testing by the Canada's National Research Council in Winnipeg shows promise for an ozone sterilization process for prion inactivation, according to its manufacturer.
This potential will represent significant advancement in the fight against an incurable disease, Creutzfeld-Jakob Disease, and its latest variant (vCJD) sometimes referred to as the human version of mad cow disease, which occurs through an infectious protein called a prion (PrP).
"A further round of testing with a higher threshold limit is now required to demonstrate how efficient is the ozone sterilization process for prion inactivation", said Simon Robitaille, R&D director at TSO3 Inc. (Technologies of Sterilization with Ozone Inc.), the product's manufacturer.
What are prions?
Prion proteins are present in most cells of the body. In its normal form (PrP), the protein causes no harm, according to a news release. However, when a normal prion comes in contact with an infectious prion protein, it changes shape to become an infectious prion (PrPSc). When the prion proteins change shape, they tend to clump together to form plaques in the brain, leaving it with sponge-like holes, a disease called TSE, or transmissible spongiform encephalopathy.
Up to March 27, 117 cases of vCJD had been diagnosed in Britain, five in France, one in Italy, one in Ireland and one in Japan. There had been no cases reported in the United States until very recently, when a 22-year-old British citizen living in Florida was reported sick with vCJD on April 19.
Most victims of vCJD die within a few months of the onset of clinical symptoms. However, specialists say the disease may take up to 15 to 20 years to incubate before such clinical symptoms may be detectable. Since several million people may have ingested potentially tainted beef products, some people think the reported total of more than 100 deaths from vCJD in the UK might represent the start of an epidemic.
It is known that the agents causing transmissible spongiform encephalopathies (TSE) such as Creutzfeldt-Jakob disease in humans are remarkably resistant to standard inactivation processes used for conventional micoorganisms.
Potential to inactivate infectious prions
Recent testing with TSO3's sterilization process on an available animal prion model shows it to have the potential to inactivate infectious prions, according to a news release. These tests were conducted by the National Research Council Canada. The ozone sterilization process achieved the limit of detection with this first round of experiments on infectious prions.
"In terms of chemistry, these positive results can easily be explained; ozone has the potential to completely eliminate prions, since ozone is quite effective on proteins and prions are proteins. Ozone literally breaks the chemical bonds," said Professor Bernard Legube, chemist at the University of Poitiers, in France and specialist in ozone and other oxidation processes.
After succeeding in this first round of experiments, other tests are required to further evaluate the inactivation ability of ozone sterilization on prion proteins. The next round of testing will take place at the National Research Council Canada laboratory, in Winnipeg, in collaboration with the Department of Microbiology and Immunology at Universite de Montreal. The purpose of upcoming assay testing in September 2002 is to examine ozone sterilization capabilities with greater threshold limits. The results, expected to be available in six to seven months, are expected to show even further the efficiency of the ozone sterilization process for prion inactivation, thereby demonstrating whether ozone can significantly reduce the risk of retransmission of the disease. An amount of approximately $400,000 (Canadian) will be invested in this project by TSO3, mainly through a new round of financing currently in progress, according to the news release. |
