B. The complete destruction of all living forms of life. Includes bacteria, spores, fungi, and viruses
D. The use of agent to lower the number of growing microorganisms. Does not provide sterility, as spores and some viruses may survive
D. An agent which lowers the count of viable microorganisms; usually applied to inanimate objects.
C. An agent which lowers the count of viable microorganisms; usually applied to patients (e.g. skin).
What function does the killing of bacteria follow at low and high concentrations of bacteriocidal agent is used?
- High concentrations killing is logarithmic
- Low concentrations killing is sigmoidal
What are the autoclave temperatures, pressures, and cycle times?
- 121 degC 15 psi 15-20 mins
- 134 degC 30 psi 4-5 mins
What are the differences between biologic indicators, process indicators, and dosage indicators?
- Biologic (best) – tests with bacillus spores to be sure spores are killed
- Process (worst) – dye changes according to temperature
- Dosage – dye changes according to temperature and time of exposure
What are the benefits of Ortho-phthalaldehyde (OPA)?
- • Requires no activation
- • Not known to irritate the eyes or nose
- • Stable over a wide pH range
- • Does not require exposure monitoring
- • Barely perceptible odor
- • Faster sterility than glutaraldehyde
What is Triclosan?
- • Bacteriostatic activity against gram-negatives and gram-positives
- • Increasingly found in personal care and consumer products
- – Additive to some cosmetics, lotions, hand soaps, toothpastes
- – Impregnated in plastics (e.g. cutting boards), polymers, textiles, implantable medical devices
What are some Ethylene Oxide advantages and disadvantages?
- • Advantages:
- – High capacity for penetration
- – Does not damage heat-labile materials
- – Evaporates without leaving a residue
- – Suitable for materials that cannot be exposed to moisture
- • Disadvantages:
- – Slow, requires very long cycle times
- – Retained in liquids and rubber material for prolonged intervals
- – Causes tissue irritation if not well aerated
- – Requires special "spark-shield"; explosion potential
What is Chlorine Dioxide?
- • Relatively new sterilization agent
- • Not yet routinely used but may replace ethylene oxide and/or chemical vapor
- • Has been used to sterilize buildings contaminated with anthrax spores (e.g. 2001) and will inactivate prions
What is the optimum UV light band to kill bacteria?
What is Hydrogen Peroxide gas plasma?
- • Also relatively new sterilization agent
- • Relatively free of toxic residuals, compatible with many medical device materials
- • Not used for liquids, certain adhesives
- • Has been used to disinfect hospitals undergoing outbreaks of carbapenem-resistant Klebsiella pneumoniae (e.g. 2012)