NR AOVT
AU Lemmer,K.; Mielke,M.; Pauli,G.; Beekes,M.
TI Prion-decontamination of surgical instruments: In vitro studies on the destabilization, degradation and removal of surface-bound PrPsc
QU International Conference - Prion diseases: from basic research to intervention concepts - TSE-Forum, 08.10.-10.10.2003, Gasteig, München - Poster session - IV-02
PT Konferenz-Poster
AB
Background: The unusual chemical resistance, thermostability and surface binding capacity of the pathological prion protein PrPsc require special inactivation and decontamination procedures in the maintenance of surgical instruments in order to prevent iatrogenic transmission of prion diseases. Therefore, an in vitro model for the assessment and screening of the decontamination capacity of medical device cleaners and disinfectants on PrPsc attached to steel surfaces was evaluated.
Methods: Groups of 30 steel wires as carriers [Zobeley et al., Mol Med 5:240-3,1999; Flechsig et al., Mol Med 7:679-84,2001] were incubated with 263K scrapie brain homogenate from hamsters, dried, and subsequently treated with chemicals known to exert a range of high to none prion inactivating effects if applied in suspension. After extensive rinsing and treatment with and without proteinase K (PK) remaining prion proteins were visualized in a sensitive Western blot assay.
Results: Prion protein was no longer detectable after exposure i) to 1 M and 0.5 M sodium hydroxide or 2.5 % and 1 % sodium hypochlorite for 5 min or longer at 22 or 55 C, ii) to a mixture of 0.2 % SDS and 0.3 % NaOH for 5 min or longer at 25 C, and iii) to 5 % SDS for 16 h at 90 C in samples with or without PK treatment. Guanidine thiocyanate and a commercially available alkaline medical device cleanser showed PrPsc destabilizing effects. With urea only a very modest PrPsc reduction was observed, while peracetic acid had no eliminating effect.
Conclusion:The in vitro carrier model confirms and expands previous findings on "prioncidal" disinfectants and may serve as a screening test for the identification of chemicals or procedures effective in the inactivation or removal of prions from surgical instruments. However, any reduction of infectivity suggested by the loss of PrPsc in the in vitro assay needs to be validated in animal experiments.
Key words: Prion disinfection, steel wire, in vitro carrier model
AD Karin Lemmer, Martin Mielke, Georg Pauli, Michael Beekes, Robert Koch-Institut, Berlin, Germany
SP englisch
PO Deutschland