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27 Cards in this Set
- Front
- Back
Disinfection
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Reducing the number of pathogenic organisms on objects or in materials so that they pose no threat of disease
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Disinfectants
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Agents that are typically applied to inanimate objects; most disinfectants do not kill spores
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Antiseptics
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Agents that are applied to living tissues; chemical agent. Destroys or inhibits growth of microorganisms.
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Sterilization
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The killing or removing of ALL micro-organisms in a material or on an object. No living organisms on an object.
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Bacteriostatic agent
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inhibits growth of bacteria
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Germicide
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capable of killing microbes rapidly; some effectively kill certain microorganisms but only inhibit the growth of others
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Bactericide
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kills bacteria; most do not kill spores
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Viricide
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Inactivates viruses
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Fungicide
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kills fungi
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Sporocide
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kills bacterial endospores or fungal spores
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Principles of sterilization and disinfection
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-a definite proportion of organisms die at a given time
-the fewer the organisms present, the shorter the time needed to achieve sterility -microorganisms differ in their susceptibility to antimicrobial agents |
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Potency of chemical agents
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-time is key
-temperature accelerates death rate -pH can increase or decrease agents potency -increased concentration can increase the effects of the agent |
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Disinfectant Criteria
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-Fast acting
-Effective against all types of infectious agents without destroying tissues or being poisonous -Easily penetrate material to be disinfected without causing harm to material -Easy to prepare and stable when exposed to light, or other environmental factors -cheap -does not smell bad |
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Protein Denaturation
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Some antimicrobials denature or unfold DNA proteins so they don't function properly (ie:heat). This is done by physically or chemically altering primary, secondary, or tertiary structures
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Hydrolysis
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Acids such as boric acid, and strong alkalis destroy proteins by hydrolyzing it
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Oxidation
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Oxidizing agents (electron acceptors), such as hydrogen peroxide. and potassium permanganate, oxidize disulfide linkages or sulfhydryl groups. Agents containing halogens also sometimes act as oxidizing agents
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Attachment of atoms or chemical groups
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-Heavy metals attach to sulfhydryl groups.
-Alkylating agents, which contain methyl group donate this group to proteins -Halogens can be substituted for hydrogen in carboxyl, sulfhydryl, amino, and alcohol groups |
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Membrane Proteins
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can be denatured by various agents
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Membrane Lipid
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Can be disrupted by substances that dissolve lipids. Alcohols, detergents, and quaternary ammonium compounds dissolve lipids.
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Surfactants
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soluble compounds that reduce surface tension
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Phenols
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(alcohols) dissolve lipids and denature proteins
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Detergent Solutions
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(wetting agents) often used with other chemical agents to help the other agent penetrate fatty substances
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Nucleic Acids (reactions)
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Alkylating agents can replace hydrogen on amino or alcohol groups in nucleic acids
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Cell Wall (reactions)
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Dyes, such as crystal violet, can interfere with the cell wall formation
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Energy producing systems
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Lactic acid and propionic acid (end products of fermentation), inhibit fermentation and thus prevent energy production in certain bacteria, molds and some other organisms
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Physical Antimicrobial Agents
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Dry Heat, Moist Heat, Pasteurization
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Physical Antimicrobial Methods
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Refrigeration/freezing, Dessication, Freeze-drying, Radiation, Filtration, Osmotic Control
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