Antibacterial protocols 7.1 Flashcards
Antisepsis
Use of chemical agents on skin or other living tissue to inhibit or eliminate microbes; no sporicidal action is implied
Disinfection
Use of physical procedures or chemical agents to destroy most microbial forms; bacterial spores and other relatively resistant organisms (e.g., mycobacteria, viruses, fungi) may remain viable; disinfectants are subdivided into high-, intermediate-, and low-level agents
Germicide
Chemical agent capable of killing microbes; includes virucide, bactericide, sporicide, tuberculocide, and fungicide
High-level disinfectant
A germicide that kills all microbial pathogens except large numbers of bacterial spores
*disinfection can generally approach sterilization
Intermediate-level disinfectant
A germicide that kills all microbial pathogens except bacterial endospores
Low-level disinfectant
A germicide that kills most vegetative bacteria and lipidenveloped and medium-size viruses
*many microbes survive
Sterilization
Use of physical procedures or chemical agents to destroy ALL microbial forms, including resilient forms such as bacterial spores, mycobacteria, nonenveloped (non-lipid) viruses, and fungi
Autoclaves and sterilization requirement
Autoclaves are sealed heating devices that use steam under pressure to kill microorganisms
- 1.1 kg/cm2 (15 lb/in2) at 121°C for 15 minutes
- Bulky or large liquids require total heating times to be extended
Why is maintaining proper temperature for autoclaves important?
because a drop of 1.7° C increases the needed exposure time by 48%
IF you can’t achieve NO moisture for the autoclave, then the temperature must reach?
temperature must reach 160° C for dry heat sterilization
How do you test autoclaves?
commercial preparations of Bacillus stearothermophilus spores in the autoclave chamber monitor effectiveness of sterilization
*ran through atuoclave and then incubated at 37° C… IF sterilization is successful, the spores are killed and fail to grow
Explain sterilization via ultraviolet radiation?
Ultraviolet radiation between 220 and 300 nm is absorbed by DNA and causes mutations or other serious effects on DNA that lead to death of the exposed organism
UV radiation is widely used to decontaminate and disinfect?
the work surface of laboratory laminar flow hoods equipped with “germicidal” UV light AND disinfects air circulating in
hospital and food preparation rooms
UV radiation has very poor?
penetrating power, limiting its use to disinfection of exposed surfaces or air but not bulk objects such as canned foods or surgical clothing
Ionizing radiation is electromagnetic radiation of sufficient energy to produce?
ions and other reactive molecular species from molecules with which the radiation particles collide
