Ch.7 The Control Of Microbial Growth Flashcards
The control of microbial growth can prevent — and ——
- Infections
- Food Spoilage
— refers to bacterial contamination
Sepsis
— is the absence of significant contamination
* ——— prevent the microbial contamination of wounds
- Asepsis
- Aseptic Surgery Technique
Sterilization: — and — all microbial life
* Used on ——
- Removing & Destroying
- Inanimate Objects
Commercial Sterilization: killing —— Endospores from canned goods, kills all spore but doesn’t turn to mush
Clostridium Botulinum
Disinfection: destroying harmful microorganisms on a ——
Nonliving surface
Antisepsis: destroying harmful microorganisms on ——
Living tissue
Degerming: the — removal of microbes from a ——
- Mechanical
- Limited area
Sanitization: lowering —— on eating utensils to safe levels
Microbial Counts
Biocide (germicide): treatments that ——
Kill microbes
Bacteriostasis: —, not — microbes
- Inhibiting
- Killing
The Rate of Microbial Death:
~ Effectiveness of treatment depends on:
* — of microbes: the more microbes there are to begin, the — it takes to — the entire populations
- Number
- Longer
- Eliminate
The Rate of Microbial Death:
~ Effectiveness of treatment depends on:
* —: — are difficult for — to reach effectively
- Environment (organic matter, temperature, biofilms)
- Biofilms
- Biocides
The Rate of Microbial Death:
~ — of —: chemical anti microbial often require extended exposure to affect more-resistant microbes or —
- Time of Exposure
- Endospore
Actions of Microbial Control Agents:
~ Alteration of membrane —:
* The susceptibility of the plasma membrane is due to its — and — components
* Certain ——— damage the plasma membrane by altering its permeability
- Permeability
- Lipids & Proteins
- Chemical Control Agents
Actions of Microbial Control Agents:
~ Damage to —(—)
* Some microbial control agents damage cellular proteins by breaking —— and ——
~ Damage to ——
- Proteins (Enzymes)
- Hydrogen Bonds & Covalent Bonds
- Nucleic Acids
Heat:
~ Heat is frequently used to — microorganisms
~ Moist heat kills microbes by ——
- Kill
- Denature Enzymes
Thermal Death Point (TDP): — temperature at which all cells in a liquid culture are killed in — minutes
- Lowest
- 10
Thermal Death Time (TDT): — time for all bacteria in a liquid culture to be killed at a particular temperature
Minimal
Decimal Reduction Time (DRT): Minutes to kill —% of a population at a given temperature
90%
Moist Heat Sterilization:
~ Moist heat ——
~ Boiling kills many vegative cells and viruses within 10 minutes
~ Large containers require — sterilization times
~ Test strips are used to indicate —
- Denatures Proteins
- Longer
- Sterility
Moist Heat Sterilization:
~ Autoclave: — under —
* —C at — psi for — minutes
* Kills all — and —
* Steam must contact the item’s —
- Steam under Pressure
- 121 C at 15 psi for 15 minutes
- Organisms & Endospores
- Surface
Heat:
~ — reduces spoilage organisms and pathogens. It also lowers microbial numbers, which prolongs milk’s good quality
* High Temperature short time (HTST): — C for — seconds, most milk
* Thermoduric (——) organisms survive, but these are unlikely to cause disease or causes refrigerated milk to spoil
~ Ultra-high-temperature (UHT): — C for — seconds on the small contains of coffee creamers
- Pasteurization
- 72 C for 15 seconds
- Heat-Resistant
- 140 C for 4 seconds
Dry Heat Sterilization:
~ Kills by —
* —
* —
* ———: the longer period and higher temperature (relatively to moist heat) are required because the heat in water is more readily transferred to a cool body than is the heat in air.
- Oxidation
- flaming
- Incineration
- Hot-air Sterilization
Filtration:
~ Passage of substance through a screen-like material
~ Used for —— materials
~ ————— remove microbes >0.3 um
~ —— remove microbes > 0.22 um
- Heat-sensitive
- High Efficiency Particulate Air (HEPA) filters
- Membrane Filters
Physical Methods of Microbial Control:
~ Low Temperature has a — effect
* —, ——, —
~ — pressure denatures proteins
~ Desiccation: — of — prevents metabolism
~ Osmotic pressure uses salts and sugars to create — environment; causes —
- Bacteriostatic
- Refrigeration, deep-freezing, lyophilization (freeze drying)
- High
- Absence of water
- Hypertonic
- Plasmolysis
Radiation:
~ Ionizing Radiation ( ——, ——, ——)
* Ionizes water to create reactive ——
* Damages DNA by causing lethal —
- X rays, gamma rays, electron beam
- Hydroxyl radicals
- Mutations
Radiation:
~ Nonionizing Radiation (—,— nm)
* Damages DNA by creating ——
- UV, 260 nm
- Thymine Dimers
Radiation:
~ Microwaves kill by —, not especially —
- Heat
- Antimicrobial
Principles of Effective Disinfection:
~ — of —
~ ——
~ —
~ —
- Concentration of Disinfectant
- Organic Matter
- pH
- Time
Phenol and Phenolics:
~ Injure — of plasma membranes, causing —
- Lipids
- Leakage
Bisphenol:
~ Contain two — groups connected by a —
~ — and —
~ Disrupt ——
- Phenol
- Bridge
- Hexachlorophene & Trisclosan
- Plasma Membrane
Halogens:
~ Iodine:
* Tincture: solution in ——
* Iodophor: combined with — molecules
* Impairs —— and alters —
- Aqueous Alcohol
- Organic
- Protein Synthesis
- Membranes
Halogens:
~ Chlorine
*——; shut down cellular enzyme systems
* Bleach: ——
* Chloramine: —+—
* Can be added to drinking water to remove potential —
- Oxidizing Agent
- Hypochlorous Acid (HOCl)
- Chlorine + Ammonia
- Pathogens
Alcohols:
~ Denature — and dissolves —
~ No effect on — and ——
~ — and —
* Require Water
- Proteins
- Lipids
- Endospores
- Non-enveloped Viruses
- Ethanol & Isopropanol
Heavy Metals & Their Compounds:
~ Oligodynamic Action: very — amount exert ——
~ — proteins
~ —,—,—,—
- Small
- Anti microbial Activity
- Denature
- Ag, Hg, Cu, Zn
Chemical Food Preservatives:
~ —— prevents wine spoilage
~ Organic Acids
* Inhibit —
* Sorbic acid, benzoic acid, and calcium propionate prevents — in acidic foods
~Nitrites and nitrates prevent ——
- Sulfur Dioxide
- Metabolism
- Molds
- Endospore Germination
Aldehydes:
~ Inactivate proteins by —— with functional groups
~ Used for preserving — and in ——
* formaldehyde and Ortho-phthaladehyde
* Glutaraldehyde is one of the few liquid chemical sterilizing agents
- Cross-linking
- Specimens
- Medical Equipment
Chemical Sterilization:
~ Gaseous sterilants cause —, replacing hydrogen atoms of a chemical group with a ——
~ Cross-links —— and —
~ Used for —— materials
* Ethylene Oxide
- Alkylation
- Free Radical
- Nucleic Acids & Proteins
- Heat-sensitive
