Journal of Hospital Infection A cold water, ultrasonic activated stream efficiently removes proteins and prion-associated amyloid from surgical stainless steel

Secker, Thomas.J.; Leighton, Timothy.G.; Offin, Douglas.G.; Birkin, Peter.R.; Hervé, Rodolphe.C.; Keevil, Charles.W.

BACKGROUND: Sterile Service Department decontamination procedures for surgical instruments struggle to demonstrate efficient removal of the hardiest infectious contaminants, such as prion proteins. A recently designed novel system, which utilises a low pressure ultrasonic activated, cold water stream, has previously demonstrated efficient hard surface cleaning of several biological contaminants. AIM: To test the efficacy of an ultrasonically activated stream for the removal of tissue proteins, including prion-associated amyloid, from surgical stainless steel (SS) surfaces. METHODS: Test surfaces were contaminated with 22L, ME7 or 263K prion infected brain homogenates. The surfaces were treated with the ultrasonically activated water stream for contact times of 5 and 10 seconds. Residual proteinaceous and amyloid contamination were quantified using sensitive microscopic analysis, and immunoblotting was used to characterize the eluted prion residues before and after treatment with the ultrasonically activated stream. FINDINGS: Efficient removal of the different prion strains from the surgical SS surfaces was observed, and reduced levels of protease sensitive and resistant prion protein was detected in recovered supernatant. CONCLUSIONS: This study demonstrated that an ultrasonically activated stream has the potential to be a cost-effective solution to improve current decontamination practices and has the potential to reduce hospital acquired infections.