Term
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Definition
| Removal or destruction of all harmful microbes. |
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Term
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Definition
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Term
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Definition
| Use of physical or chemical agents to remove orgs from inanimate or nonliving objects (disinfectants) |
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Term
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Definition
| Removal of orgs from living tissues (ex: alcohol) |
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Term
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Definition
| Removal of microbes by scrubbing |
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Term
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Definition
| Disinfecting public places and utensils by reducing # of pathogens to safe levels (steam, hot water, scrubbing, etc.) |
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Term
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Definition
| Use of heat to kill pathogens and reduce spoilage microbes in food and beverages. (milk, fruit juices, wine, beer) |
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Term
| -static vs. -cidal agents |
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Definition
-static inhibit microbes
-cidal kill them |
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Term
| Factors Affecting Microbial Control |
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Definition
- nature of sites to be treated.
- susceptibility of microbes
- environmental conditions |
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Term
| Methods for Evaluating Disinfectants and Antiseptics |
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Definition
1. Phenol Coefficient
2. Use-Dilution
3. Disk-Diffusion Method (Kirby-Bauer)
4. In-Use Test |
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Term
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Definition
| Divide amount of agent that kills by Amount of phenol that kills |
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Term
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Definition
| Standard - dip metal cylinders into broth cultures 1 min. Immerse into various dilutions of disinfectant for 10 min, rinse, and add to sterile broth and incubate 48 hrs then look for growth |
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Term
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Definition
| Used in Lab - Kirby-Bauer method - Soak sterile paper disk in agent, place on swabbed agar plate, compare zones of inhibition. Must compare diffusion constants! |
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Term
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Definition
| Swabs taken from objects before and after disinfection then placed onto growth media to determine effectiveness. |
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Term
| Physical Methods of Microbial Control |
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Definition
1. Heat
2. Refrigeration and Freezing
3. Dessication and Lyophilization
4. Filtration
5. Radiation |
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Term
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Definition
Moist Heat - Boiling (everything but endospores) Autoclaving - 15 psi for 15 min 121 *C. Pasteurization - Batch (30 min 63*C), Flash (15s 72*C) Ultrahigh (134C for 1s). Ultrahigh Temp - 140C for 1s then cooled
Dry Heat - Powders 171C 1hr 160c 2hr |
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Term
| Refrigeration and Freezing |
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Definition
Refrigeration slows metabolism and growth 0-7C Psychrophiles
Freezing Ice crystals puncture cell membrane - slow is better (-30 to -80C storage of microbes with glycerol) |
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Term
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Definition
| (drying) remove water to stop metabolism (ex: jerky) |
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Term
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Definition
| Freeze drying - freezes then uses vacuum to remove water |
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Term
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Definition
| passage of fluid through membrane with small pores |
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Term
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Definition
| High concentration of salt/sugar inhibit growth by creating hypertonic solutions and causing water to leave cells. Molds aren't inhibitied - spores! |
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Term
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Definition
| beams, rays, cause electrons to be ejected from atoms, disrupting H bonding, oxidizing double bonds, creating hydroxl ions. DNA easily damaged leading to mutations. |
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Term
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Definition
| excite electrons and cause to chemical bonds to be formed, damaging proteins and NA's. UV light-260nm not very penetrating-thymine dimers block transcription and DNA replication. |
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Term
| Chemical Methods of Microbial Control |
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Definition
| Used more- act on proteins, membranes or DNA. Effects vary with temp, time of exposure, concentration, freshness, amnt of organic matter present. |
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Term
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Definition
| Chemical - denature proteins and disrupt cell membranes, effective in presence of organic matter (advantage). Disadvantages: odor and side effects |
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Term
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Definition
| everything but spores. isopropanol and ethanol common. Combined with other chem - tinctures. Most effective with water-Both polar and nonpolar effected. No mess but doesn't stay on long enough. |
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Term
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Definition
| I, Cl, Br. Used alone or combined. Organic/inorganic forms are used. I-releases slowly, non-staining, non-irritating. Cl-Treat water. May be gas. Can produce carcinogens in water. Br-Used in hot tubs slow evaporate, protects from herpes. |
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Term
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Definition
| Anaerobes. Damage DNA. h2o2- inanimate objects. neutralized by catalase from damaged skin cells. Chems overcome. O-zone - exposing 02 to electricity, expensive. Peracetic Acid - Sporocide, sterilize med. equipment |
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Term
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Definition
| "surface active agents" - loosens molecules. Soaps - break up oils. Detergents- + charged, "quats"-quaternary Ammonium compound, Mouthwashes, disrupt cell membrane, not effective against envelope viruses or spores. |
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Term
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Definition
| As, Zn, Hg, Ag, Cu. Denatures proteins. Silver-surgical dressings, burn creams, catheters. Copper-Interferes with Chlorophyll synthesis (algae), pathogens don't have chlorophyll tho!! |
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Term
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Definition
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Term
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Definition
| Used to control mildew in paint - mercurochrome, merthiolate |
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Term
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Definition
| end in "-CHO" denature proteins, Gluteraldehyde-2% used to kill bacteria, fungi, viruses, 10 min. 10 hr-sterilizes. safer, less irritating than Formaldehyde-37% used for embalming, disinfection. Irritates mucous membranes, and carcinogenic. |
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Term
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Definition
| Sterilize heat sensitive items, highly reactive, sporocidal, very effective, but many hrs. Ethylene oxide-Chambers in hospitals and dentists, explosive, poisonous. Propylene oxide-Same. Beta-propiolactone-same, carcinogenic |
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Term
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Definition
| Antimicrobial enzymes can kill microbes. (ex:lysozyme (tears), prionzyme (mad cow) |
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Term
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Definition
Antibiotics-chem produced by microbes that kill other microbes.
Semisynthetics-Chem modified antibiotic |
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Term
| Development of Resistant Microbes |
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Definition
| Overuse of disinfectants? like Triclosan. Never see resistance to ones that destroy cell membranes |
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