Medical MicrobiologyMedical Microbiology

Chapter 67 - PrionsChapter 67 - Prions

PrionsPrions Proteinaceous infectious particles with no Proteinaceous infectious particles with no

known genetic material!known genetic material! Diseases – Box 67-1Diseases – Box 67-1 These are all neurodegenerative diseasesThese are all neurodegenerative diseases These all have very long incubation periods These all have very long incubation periods

(up to 30 years for the human diseases)(up to 30 years for the human diseases) These proteins elicit no immune These proteins elicit no immune

response, are extremely resistant to response, are extremely resistant to inactivation by heat, disinfectants, and inactivation by heat, disinfectants, and radiation.radiation. Formaldehyde, UV radiation, heat up to 80Formaldehyde, UV radiation, heat up to 80ºº C C

PrionsPrions Infection cycle – Figure 67-1Infection cycle – Figure 67-1 Transmission:Transmission:

InjectionInjection Transplanted tissueTransplanted tissue Contaminated medical devicesContaminated medical devices FoodFood

Box 67-3Box 67-3 Stories of kuru and vCJDStories of kuru and vCJD Box 67-4Box 67-4