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29 Cards in this Set
- Front
- Back
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Physical agent that destroys most microbial life and reduces contamination on inanimate surfaces. Destroys or removes vegetative pathogens but not bacterial endospores. Can be toxic in the amount required to be effective. Remove harmful toxins of microorganisms from materials. Example: 5% bleach. Boiling water
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Disinfection
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Is the same as disinfection, except living surface is involved. Chemicals applied to body surfaces (skin, wound or surgical incision) to destroy or inhibit vegetative pathogens. Example: Used in preparation of surgery: iodine, hydrogen peroxide, germicidal soap.
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Antisepsis
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A process that destroys or removes all viable microorganisms, including viruses. It is used on inanimate objects.
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Sterilization
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The # of microorgansims; The nature of microorgansims in the population; The temperature & pH; concentration of agent; How it kills or inhibits organism (mode of action); The presence of solvents, interfering organic matter and inhibitors.
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Influences on Microbial Agents
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Cell wall, Cell membrane, Cellular synthetic processes (DNA, RNA), proteins
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Antimicrobial Agents Mode of Action
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Detergents that work as microbicidal agents because they lower the surface tension of cell membranes.
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Surfactants
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Air with a low moisture content that has been heated from a flame or electric heating coil; temperatures range from 160 C and up.
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Dry Heat
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Occurs in the form of hot water, boiling water, or steam; temperatures range from 60 C to 135 C.
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Moist Heat
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Which is better, dry heat or moist heat, and why?
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Moist Heat; achieves sterilization in less time
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A disinfection technique in which heat is applied to liquids to kill potential agents of infection.
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Pasteurization
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What is UHT?
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Ultrahigh Temperature
134 ̊C – for 1 to 2 seconds; sterile milk is processed at this temperature. |
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When the bonds that maintain the secondary and tertiary structure of the protein are broken.
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Denaturation
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Placing organisms at 4°C is which?
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Bacteriostatic
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This effect, slows growth of cultures and microbes in food during processing and storage; it merely retards the activities of most microbes.
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Cold Treatment
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Vegetative cells directly exposed to room temperature gradually become dehydrated.
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Desiccation
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Gamma rays (High energy)
X-rays (Intermediate energy) Cathode rays (least energy) |
Ionizing Radiation
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Ultraviolet Rays
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Nonionizing Radiation
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Radiation that ejects orbital electrons from an atom, it causes ions to form.
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Ionizing Radiation
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Radiation that excites atoms by raising them to a higher energy state. Excitement leads to the formation of abnormal bonds within molecules such as DNA and is a source of mutations.
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Nonionizing Radiation
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Radiation enters a cell, strikes molecules and excites them. The effect on DNA is a mutation by formation of abnormal bonds.
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Nonionizing Radiation
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Radiation penetrates a solid barrier, bombard a cell, enter it, and dislodge electrons from molecules. Breakage of DNA creates massive mutations and damage to proteins prevents them from repairing it.
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Ionizing Radiation
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Fluorine, Bromine, Chlorine & Iodine
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Halogen microbial agents
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Halogen Microbial Agent that denatures enzyme due to disrupt HS-SH (thiols) causing permanent denaturation; Drinking water and swimming pool; Less effective with light, Alkaline ph
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Chlorine
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Halogen Microbial Agent that denatures protein; Interfere with H-Bonds and disulfide bonds; topical antiseptic; Not affected by pH and organic matter
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Iodine
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An agent that is effective against anaerobic microbes.
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Hydrogen Peroxide
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An agent that forms hydroxyl free radicals that are highly toxic and reactive to cells.
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Hydrogen Peroxide
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An agent that is effective against spores.
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Ethylene Oxide
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An agent that can sterilize and disinfect plastic materials and delicate instruments in hospitals and industries.
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Ethylene Oxide
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An agent that can sterilize prepackaged medical devices, surgical supplies, syringes, and deposable Petri dishes. It disinfects sugar, spices, dried foods and drugs.
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Ethylene Oxide
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