Steralization Flashcards
What is steralization?
Complete destruction or physical removal of all microbes including resistant forms such as spored and mycobacterio/ nonenveloped viruses and fungi.
Moist heat
Saturated Steam under pressure (121-132 fro 15 minutes or more!)
Most commonly used kills bacteria and spores!
How can prions be destroyed?
Boil in 1N NaOH for 10 minutes followed by extended autoclaving.
Is boiling a steralization method?
NO!
It is a method of disinfection.
What does dry heat eliminate?
Kills spores but may not eliminate pyrogens.
Only to be used for materials that can be damaged by moist heat or where moist heat cannot penetrate.
Kills microbes by irreversibly denaturing proteins, single strange DNA breaks and compromising membrane integrity.
How does ethylene oxide gas work?
Used for heat and moisture sensitive medical devices without deleterious effects on the material used.
Kills by alkylating protein, DNA, RNA within cells preventing normal cellular metabolism and replication.
How does irradiation work?
UV irradiation used in lab safety cabinets.
UV irridation and ionizing gamma rays.
Used to sterilize heat sensitive pre packed single use plastic items includin syringes and catheters.
Gamma ray ionizing radiations.
Kills by elliciting DNA damage through free radical formation.
How do aldehydes work?
Used as a disinfectant as well as a sterilizing agent by alkylating the amino and sulfhydryl groups of proteins and ring nitrogen atoms of purine bases.
Peracetic acid
Oxidizes with non-toxic end products. Removes surface contaminants on medical surgical, and dental instruments chemically.
What is disinfection?
Process of removing or killing microbes but not all of them.
More resilient organisms may survive these procedures.
Glutaraldehyde, oxidizing agents such as peracetic acid, hydrogen peroxide and bleach are all examples of…
High level disinfectants used for devices that cannot be sterilized.
Alcohols, iodine containing compounds and phenolic compounds are all examples of…
All examples of intermediate level disenfectants that are used on semi-critical instruments that are unlikely to be infected by spores.
Quaternary ammonium compounds are examples of
Low level disinfectants such as stethoscopes, blood pressure cuffs and electrocardiogram electrodes.
What are antiseptics?
Agents used to lower the number of microorganisms on the skin surfaces. Non of them kill spores but are all efficacious against vegatative bacteria.
how does alcohol disinfect?
Kills most microbes but not spores mostly through denaturation of bacterial proteins and inhibition of metabolite synthesis.
Most effective in the presence of water (70% alcohol more effective than 95%) but not as effective as iodine compounds.
How do phenolic compounds work?
These penetrate and disrupt the cell wall in high concentrations.
Denature proteins and lipids in the cytoplasmic membrane and lyse cells.
How do Iodine containing solutions work?
Most effective antiseptic used.
Kill organisms but not spores.Penetrate the cell wall of microorganisms and cause disruption of proteins and nucleic acid structure and synthesis.
Tincture of iodine
2% solition of iodine and potassium iodide in alcohol. Good for skin with blood culture.
Iodophors
Combination of iodine and stabilizing agent or carrier. Providone iodine is best known and most commonly used.
How does Chlorhexidine work?
Antiseptic with broad activity but slower rate of killing than alcohol.
Better antiseptic for skin preventing bloodstream infections with patients that have central lines compared to providone iodine.
How do quaternary ammonium compounds work?
These attack energy producing enzymes, denature cell proteins and disrupt cellular membranes.
are not effective against many organisms.
How does triclosan work?
Found in antiseptics and hand soaps as well as some tooth pastes.
Does not kill bacterial spores but inhibits lipid synthesis and disrupts cell membrane at high concentrations.
What is pasteurization?
The process of healing liquids to a specific temeprature to destroy harmful microbes
doesnt kill all microbes just systematically reduces there numbers.
