The infectious agent shown in the picture below are best killed by?
A. Autoclaving at 121°C.
B. 5% formaline.
C. Sodium hydroxide.
D. Sodium hypochloride.
The infectious agent shown in the picture above are prions.
- A prion is an infectious agent composed entirely of protein material, called PrP (short for prion protein).
- They are suspected to be the cause of transmissible spongiform encephalopathies.
- The infectious agent responsible for the transmission of prion diseases is a misfolded conformer of the prion protein, PrPSc, a pathogenic isoform of the host-encoded, cellular prion protein,PrPC.
- Prions are best killed by Sodium hydroxide.
- Incineration is apparently the only way of disinfecting prion-contaminated materials or tissues.
- Boiling or irradiation have no effect and even routine autoclaving (at 121°C) is not reliable. Therefore, where there is a risk of exposure, surgeons use disposable instruments.
- To sterilize reusable instruments, WHO currently recommends combined use of a strong solution of sodium hydroxide and extended autoclaving at 134°C.
“Autoclaving at 134°C for 5 hrs or treatment with 2 N NaOH for several hours is recommended for sterilization of prions”.