NR ATJF
AU Lemmer,K.; Mielke,M.; Kratzel,C.; Joncic,M.; Kampf,K.; Borchers,U.; Pauli,G.; Beekes,M.
TI Prion-decontamination of surgical instruments: Comparison of in vivo and in vitro results - A follow up study
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Decontamination DEC-12
PT Konferenz-Poster
AB
The unusual chemical resistance, thermostability and tenacity of prions require special inactivation and decontamination procedures in order to prevent accidental transmission of prions by surgical instruments. Although bioassays provide the most sensitive method for the detection of prions, in vitro studies can contribute to substantially reduce the number of animals in biotitrations. In our experiments we screened and assessed the decontamination capacity of medical device cleaners and disinfectants, firstly in an in vitro assay using steel wires as PrPsc carriers and subsequently in an in vivo carrier assay, once the chemical has been found effective in vitro.
The wires were incubated with 263K scrapie brain homogenate from hamsters, dried and subsequently treated with potentially decontaminating chemicals. After extensive rinsing and treatment with or without proteinase K the wire and the decontamination solution after wire incubation were examined by Western blotting for residual PrPsc, or PrP27-30. The results provided information about the efficiency and the mechanism of decontamination achieved by the examined cleaner or disinfectant. Being primarily interested in the identification of products suitable for routine decontamination procedures of surgical instruments we examined an alkaline cleaner and mixtures of low concentrated chemicals like SDS/NaOH and peracetic acid (PAA)/NaOH. The high efficiency of the first two products observed in vitro could be confirmed so far in ongoing bioassays: After more than 300 days after stereotactical i.c. implantation the recipients did not show clinical disease. With PAA/NaOH, however, thorough decontamination of the wires from PrPsc suggested by the in vitro assay could not be confirmed by in vivo titration of infectivity.
In general, in vitro carrier testing had a high predictive value for subsequent in vivo titration, but bioassays appear to remain mandatory for the definite evaluation of candidate cleaners or disinfectants.
AD Karin Lemmer, Martin Mielke, Christine Kratzel, Marion Joncic, Kristin Kampf, Ulrich Borchers, Georg Pauli, Michael Beekes, Robert Koch-Institut, 13353 Berlin, Germany
SP englisch
PO Deutschland