NR ATJM
AU Käsermann,F.; Kempf,C.
TI Different Mechanisms are Involved in the Decontamination of TSE by Sodium Hypochlorite and Sodium Hydroxide
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Decontamination DEC-19
PT Konferenz-Poster
AB
An important aspect in the prevention of prion disease transmission is the decontamination of potentially contaminated fluids, equipment and medical instruments. Sodium hypochlorite and sodium hydroxide solutions are commonly used as a disinfectant. They are known to inactivate a variety of pathogens. However, information about their effect on the agents causing transmissible spongiform encephalopathy (TSE) is sparse and contradictory.
Hamster or mouse scrapie brain homogenate, containing the, disease-associated form of the prion protein (PrPsc), was exposed to NaOCl and NaOH, respectively. Kinetic studies showed, that the titre of PrPres, the proteinase K resistant form of the prion protein, was reduced to background when treated with hypochlorite (100 ppm). This reduction is not due to the high pH of NaOCl, since no difference in kinetics was observed when the NaOCl solution was neutralised. NaOH in the millimolar range rapidly abolished the proteinase K resistant form of the prion protein (PrPres) from mouse (Me7) or hamster scrapie (263K). NaOH treatment converted Prpsc into a protease sensitive form either in solution or when adsorbed to a metallic surface.
Further studies with recombinant prion protein and other model proteins indicate, that treatment of brain homogenate with sodium hypochlorite, involves a different mechanism than the conformational rearrangement from the PK resistant form of PrP to the sensitive form when treated with sodium hydroxide. The reduction of the PrPres titre after NaOCI treatment is rather due to a decomposition of the prion protein.
Our results imply that a commonly used cleaning procedure for the decontamination of metal surfaces (treatment with bleach, NaOH or a combination of both), can substantially lower the risk of TSE cross-contamination.
AD Fabian Käsermann, Christoph Kempf, University of Bern and ZLB Behring, Switzerland
SP englisch
PO Deutschland