Decontamination of prions, prion-associated amyloid and inefectivity from surgical stainless steel - implications for the risk of iatrogenic transmission of CJD

The physicochemical nature of the infectious agent in prion diseases creates a<br/>significant challenge for decontamination services. It has been shown to be both resistant to<br/>standard methods of decontamination, used to inactivate viruses and bacteria, and to associate<br/>avidly with surgical stainless steel. Moreover, the pathophysiology of the variant, iatrogenic<br/>and sporadic forms of Creutzfeldt-Jakob Disease (CJD) suggests deposition of the infectious<br/>agent across a wide range of extraneural, lymphoid tissues, as well as in the skeletal muscle<br/>and blood. Coupled with the potential for asymptomatic carriers, there is a significant risk of<br/>iatrogenic transmission of CJD through both neurosurgical procedures and standard surgery.<br/><br/>This PhD study was undertaken in order to improve methods of instrument<br/>decontamination and to evaluate prion detection techniques and their applicability for the<br/>assessment of prion inactivation and removal. The project has provided relevant, critical<br/>assessment of hospital decontamination procedures, in addition to guidance on how working<br/>protocols should be improved to provide a cleaner and safer end product for the patient.<br/>Moreover, laboratory studies have been performed to evaluate current methods of prion<br/>decontamination in the context of hospital procedures for instrument reprocessing. Challenges<br/>faced by sterile service departments, such as soil drying and surface degradation, have been<br/>addressed and their impact on the risk of iatrogenic transmission of prions has been<br/>investigated. Critically, the use of a fluorescent amyloid fluorophore for the detection of prionassociated<br/>amyloid as a marker for disease permitted the investigation of the role of amyloid<br/>in infectious disease under denaturing conditions. Correlation of this detection technique with<br/>the identification of PrPres by Western blot and infectious disease suggested that, whilst<br/>fluorescent detection of prion-associated amyloid was more sensitive than Western blot, PrPres<br/>detection was more specific relative to infectivity. Improved fluorophores, with greater<br/>sensitivity, have been evaluated which will enhance in situ detection of prions in the future.

Name dc:type.qualificationname

Ph.D.

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Southampton

Year dc:date.issued

2009

Author dc:creator

• Howlin, Robert

Advisor dc:contributor.advisor

• Keevil, C.W.