Infectivity of prion protein bound to stainless steel wires: a model for testing decontamination procedures for transmissible spongiform encephalopathies.
OBJECTIVE
To establish an animal model to study transmissible spongiform encephalopathy using hamsters and steel wires contaminated with infectious brain materials as transfer vehicles, and, based on this model, to test decontamination procedures against the infectious prion proteins on the steel wires as a near real situation bioassay.


METHODS
Infectious brain materials were given to healthy hamsters intracerebrally either as a suspension or as dried materials on the surface of steel wires. The animals were observed for 18 months. During this period, animals showing definitive clinical signs were euthanized. Decontamination studies were performed by reprocessing contaminated steel wires with different disinfection agents and procedures before implantation.


RESULTS
Pathological prion proteins were able to bind to the steel wires and caused disease after the contaminated wires were implanted in the brains of hamsters. When the contaminated wires were treated with different reprocessing procedures before implantation, infectivity was reduced, which was manifested directly by prolonged survival time of the test animals. These results show that this model can be used as a bioassay to validate reprocessing procedures for surgical instruments.


CONCLUSIONS
At the time of submission of this article, only the group of hamsters incubated with wires reprocessed with an alkaline detergent, followed by sterilization with a modified cycle in a hydrogen peroxide gas plasma sterilizer (4 injections), showed no clinical signs of disease and remained alive. Two animals from the group receiving sodium hydroxide followed by autoclaving (at 134 degrees C for 18 minutes) died. Furthermore, the tested enzymatic cleaning agent seemed to have no positive effect.
Yan
Zheng-Xin
ZX
SMP GmbH Pruefen Validieren Forschen, Tubingen, Germany.
Stitz
Lothar
L
Heeg
Peter
P
Pfaff
Eberhard
E
Roth
Klaus
K
D000818:Animals; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use*; D001921:Brain / Q000473:pathology*; D006224:Cricetinae; D003666:Decontamination / Q000379:methods*; D003902:Detergents / Q000627:therapeutic use*; D006861:Hydrogen Peroxide / Q000627:therapeutic use*; D017096:Prion Diseases / Q000517:prevention & control* / Q000635:transmission; D011328:Prions / Q000187:drug effects* / Q000472:pathogenicity; D013193:Stainless Steel
D000891:Anti-Infective Agents, Local; D003902:Detergents; D011328:Prions; D013193:Stainless Steel; D006861:Hydrogen Peroxide