Decontamination of surgical instruments from prions. II. In vivo findings with a model system for testing the removal of scrapie infectivity from steel surfaces
The unusual resistance of agents causing transmissible spongiform encephalopathies (TSEs) to chemical or thermal inactivation requires special decontamination procedures in order to prevent accidental transmission of these pathogens by surgical instruments. In the search for effective, instrument-compatible and routinely applicable decontamination procedures, a previous study [Lemmer, K., Mielke, M., Pauli, G. & Beekes, M. (2004). J Gen Virol85, 3805–3816] identified promising reagents in an in vitro carrier assay using steel wires contaminated with the disease-associated prion protein, PrPSc. In the follow-up study presented here, these reagents were validated for their decontamination potential in vivo. Steel wires initially loaded with ≥3×105 LD50 of 263K scrapie infectivity were implanted into the brains of hamsters after treatment for decontamination and subsequently monitored for their potential to trigger clinical disease or subclinical cerebral PrPSc deposition within an observation period of 500 days. It was found that routinely usable reagents such as a commercially available alkaline cleaner (pH 12.2) applied for 1 h at 23 °C or for 10 min at 55 °C and a mixture of 0.2 % SDS and 0.3 % NaOH (pH 12.8) applied for 5 or 10 min at 23 °C achieved removal of 263K scrapie infectivity below the threshold of detection (titre reduction of ≥5.5 log10 units). The increasing use during the past few years of similar model systems by different research groups will facilitate comparison and integration of findings on the decontamination of steel surfaces from prions. Methods identified as highly effective in the 263K steel wire model need to be validated for human TSE agents on different types of instrument surfaces.
BeekesM.,
BaldaufE.,
DiringerH.1996; Sequential appearance and accumulation of pathognomonic markers in the central nervous system of hamsters orally infected with scrapie. J Gen Virol 77:1925–1934[CrossRef]
BeekesM.,
MielkeM.,
PauliG.,
BaierM.2004; Aspects of risk assessment and risk management of nosocomial transmission of classical and variant Creutzfeldt–Jakob disease with special attention to German regulations. In Prions. A Challenge for Science, Medicine and the Public Health System, Contributions to Microbiologyvol. 11 pp 117–135Edited byRabenauH. F.,
CiantlJ.,
DoerrH. W.
Basel: Karger;
BrownP.,
RohwerR. G.,
GajdusekD. C.1986; Newer data on the inactivation of scrapie virus or Creutzfeldt–Jakob disease virus in brain tissue. J Infect Dis 153:1145–1148[CrossRef]
DeleaultN. R.,
HarrisB. T.,
ReesJ. R.,
SupattaponeS.2007; Formation of native prions from minimal components in vitro . Proc Natl Acad Sci U S A 104:9741–9746[CrossRef]
KimberlinR. H.,
WalkerC. A.,
MillsonG. C.,
TaylorD. M.,
RobertsonP. A.,
TomlinsonA. H.,
DickinsonA. G.1983; Disinfection studies with two strains of mouse-passaged scrapie agent. Guidelines for Creutzfeldt–Jakob and related agent. J Neurol Sci 59:355–369[CrossRef]
LemmerK.,
MielkeM.,
PauliG.,
BeekesM.2004; Decontamination of surgical instruments from prion proteins: in vitro studies on the detachment, destabilization and degradation of PrPSc bound to steel surfaces. J Gen Virol 85:3805–3816[CrossRef]
LipscombI. P.,
PinchinH. E.,
CollinR.,
HarrisK.,
KeevilC. W.2006; Are surgical stainless steel wires used for intracranial implantation of PrPSc a good model of iatrogenic transmission from contaminated surgical stainless steel instruments after cleaning?. J Hosp Infect 64:339–343[CrossRef]
Schulz-SchaefferW. J.,
TschokeS.,
KranefussN.,
DroseW.,
Hause-ReitnerD.,
GieseA.,
GroschupM. H.,
KretzschmarH. A.2000; The paraffin-embedded tissue blot detects PrPSc early in the incubation time in prion diseases. Am J Pathol 156:51–56[CrossRef]
TaylorD. M.2004; Resistance of transmissible spongiform encephalopathy agents to decontamination. In Prions. A Challenge for Science, Medicine and the Public Health System, Contributions to Microbiologyvol. 11 pp 136–145Edited byRabenauH. F.,
CiantlJ.,
DoerrH. W.
Basel: Karger;
TaylorD. M.,
FraserH.,
McConnellI.,
BrownD. A.,
BrownK. L.,
LamzaK. A.,
SmithG. R.1994; Decontamination studies with the agents of bovine spongiform encephalopathy and scrapie. Arch Virol 139:313–326[CrossRef]
WeberP.,
GieseA.,
PieningN.,
MittereggerG.,
ThomzigA.,
BeekesM.,
KretzschmarH. A.2007; Generation of genuine prion infectivity by serial PMCA. Vet Microbiol 123:346–357[CrossRef]
YanZ. X.,
StitzL.,
HeegP.,
PfaffE.,
RothK.2004; Infectivity of prion protein bound to stainless steel wires: a model for testing decontamination procedures for transmissible spongiform encephalopathies. Infect Control Hosp Epidemiol 25:280–283[CrossRef]
Decontamination of surgical instruments from prions. II. In vivo findings with a model system for testing the removal of scrapie infectivity from steel surfaces