Elimination of transmissible spongiform encephalopathy infectivity and decontamination of surgical instruments by using radio-frequency gas-plasma treatment.
It has now been established that transmissible spongiform encephalopathy (TSE) infectivity, which is highly resistant to conventional methods of deactivation, can be transmitted iatrogenically by contaminated stainless steel. It is important that new methods are evaluated for effective removal of protein residues from surgical instruments. Here, radio-frequency (RF) gas-plasma treatment was investigated as a method of removing both the protein debris and TSE infectivity. Stainless-steel spheres contaminated with the 263K strain of scrapie and a variety of used surgical instruments, which had been cleaned by a hospital sterile-services department, were examined both before and after treatment by RF gas plasma, using scanning electron microscopy and energy-dispersive X-ray spectroscopic analysis. Transmission of scrapie from the contaminated spheres was examined in hamsters by the peripheral route of infection. RF gas-plasma treatment effectively removed residual organic residues on reprocessed surgical instruments and gross contamination both from orthopaedic blades and from the experimentally contaminated spheres. In vivo testing showed that RF gas-plasma treatment of scrapie-infected spheres eliminated transmission of infectivity. The infectivity of the TSE agent adsorbed on metal spheres could be removed effectively by gas-plasma cleaning with argon/oxygen mixtures. This treatment can effectively remove 'stubborn' residual contamination on surgical instruments.
Baxter
H C
HC
School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3JJ, UK.
Campbell
G A
GA
School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3JJ, UK.
Whittaker
A G
AG
School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3JJ, UK.
Jones
A C
AC
School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3JJ, UK.
Aitken
A
A
School of Biological Science, University of Edinburgh, Darwin Building, Edinburgh, UK.
Simpson
A H
AH
Department of Orthopaedics and Trauma, University of Edinburgh, Edinburgh, UK.
Casey
M
M
Sterile Services Department, Royal Infirmary of Edinburgh, Little France, Edinburgh, UK.
Bountiff
L
L
Moredun Research Institute, Penicuik, Bush Loan, Edinburgh, UK.
Gibbard
L
L
Moredun Research Institute, Penicuik, Bush Loan, Edinburgh, UK.
Baxter
R L
RL
School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3JJ, UK.
D000818:Animals; D001128:Argon; D006224:Cricetinae; D004195:Disease Models, Animal; D004203:Disinfection / Q000379:methods*; D005260:Female; D005740:Gases; D010100:Oxygen; D017096:Prion Diseases / Q000517:prevention & control*; D011328:Prions; D011846:Radio Waves; D013193:Stainless Steel; D013525:Surgical Instruments
D005740:Gases; D011328:Prions; D013193:Stainless Steel; D001128:Argon; D010100:Oxygen