Exam 1 - Ch. 9 - Controlling Microbial Growth in the Environment. Flashcards
Removal or destruction of ALL microbes, including viruses and bacterial endspores, in or on an object.
sterilization
An environment or procedure that is free of contamination by pathogens.
aseptic
Us of physical or chemical agents known as disinfectants to inhibit or destroy microorganisms.
disinfection
Does disinfection guarantee that ALL pathogens are eliminated?
NO
In microbial control, when a chemical is used on skin or other tissue, the process in known as ____?
antisepsis
The chemical used on the skin to control microbes is called what?
antiseptic
Removal of microbes from a surface by scrubbing.
Degerming
Process of disinfecting places and utensils used by the public to reduce the number of pathogenic microbes to meet accepted health standards.
Sanitization
Use of heat to kill pathogens and reduce the number of spoilage microorganisms in food and beverages.
Pasteurization
Suffixes to indicate that a chemical or physical agent inhibits microbial metabolism and growth.
-stasis, -static
Suffix that refers to agents that destroy of permanently inactivate a particular type of microbe.
-cide, -cidal
Permanent loss of reproductive ability under ideal environmental conditions.
Microbial death
Measurement of efficacy of an antimicrobial agent.
Microbial death rate
Tow main categories of actions of antimicrobial agents
Alteration of cell walls and membranes.
Damage to proteins and nucleic acids.
What two factors affect the efficacy of antimicrobial methods.
Site to be treated.
Relative susceptibility of microorganisms.
Which organisms are harder to kill?
Prisons, endospores
Which organisms are easiest to kill - least resistant?
Gram + bacteria.
Which gram bacteria is more resistant to antibiotics?
Gram (-)
Why are Gram (-) more resistant to antibiotics?
Has a thinner phospholipids but has two of them and have more R plasmids
Is moist heat more effective than dry heat in controlling microbes?
YES
What are the methods of moist heat in microbial control?
Boiling
Autoclaving
Pasteurization
Ultra-high temperature sterilization
What is important when using boiling for microbial control?
Boiling time is critical
What can survive boiling?
Endospores, prions, protozoan cysts, and some viruses.
What is autoclaving?
Pressure applied, prevents steam from escaping.
Is pasteurization sterilization?
NO
What is the ultimate means of sterilization?
Incineration
Does dry heat require higher temperature and longer times than moist heat?
YES
What type of microbes can multiply in refrigerated foods?
Psychrophilic microbes
Method of microbial control that decreases microbial metabolism, growth, and reproduction.
Refrigeration and freezing.
What are notable exceptions to the refrigeration method?
Listeria, yersinia
What is it called when using drying to inhibit growth due to removal of water?
dessication
What is used for long-term preservation of microbial cultures?
lyophilization (freeze drying)
Lyophilization prevents formation of what?
Ice crystals
Passage of a fluid through a sieve designed to trap particles and separate them from the fluid.
filtration
High concentrations of salt or sugar in food to inhibit growth of microbes.
Osmotic pressure
What have a greater ability to survive hypertonic solutions than bacteria?
fungi
What are two types of ionizing radiation used in control of microbes?
electron beams and
Gamma rays
Ionizing radiation that is effective at killing but does not penetrate well.
Electron beams
Ionizing radiation that penetrates well but requires hours to kill microbes.
Gamma rays
Non - ionizing radiation that does not penetrate well.
UV light
What is nonionizing radiation suitable for?
Disinfecting air,
Transparent fluids
Surface of objects
Lysol and pine-sol are what types of chemical methods of microbial control?
Phenol and phenolic
Phenol and phenolics have a disagreeable ____ and are _____ to _____ disinfectants.
Odor
Intermediate
Low-level
Intermediate level disinfectant (chemical) that is more effective than soap. Example: rubbing alcohol, ethanol.
alcohols
Chemical disinfectant. Intermediate level using iodine, chlorine, bromine, fluorine.
Halogens
Examples of Halogens.
Bleach, iodophores (betadine), chlorine
What halogen is used in preparation for surgery?
Betadine (iodophor)
High level disinfectants. Ex: peroxides, ozone, peracetic acid.
Oxidizing agents
Why do you not want to use hydrogen peroxide for wound care?
It is cytotoxic to health cells and granulating tissues.
What to use to clean wounds?
Normal saline
Commercial wound cleanser
Why use saline for wound cleaning?
It is physiologic and will always be safe.
Soaps and detergents are an example of what kind of chemical microbial control?
surfactants
What do you want to use on your tables in the office?
QUATS - quaternary ammonium compounds
Are soaps antimicrobial?
No, but good for degerming..
How many wipe should you use to clean tables?
Enough to visibly wet for four minutes
What are low level bacteriostatic and fungistatic agents?
Heavy metals
What causes blindness in babies?
N. gonorrheoaea
What did they used to prevent blindness in babies?
1% silver nitrate
What was used in vaccines but replaced in 1999.
Thimerosal
Compounds containing terminal -CHO groups in chemical methods of microbial control.
aldehydes
What is used in embalming?
Formalin - formaldehyde + water
What aldehyde is used to disinfect and sterilize labs, hospitals, and dental offices?
Glutaraldehyde
What are some gaseous agents used in closed chambers to sterilize items?
Ethylene oxide
Where is ethylene oxide used?
Dental offices and hospitals
What are disadvantages of gaseous agents?
Can be hazardous to people
Often highly explosive
Extremely poisonous
Potentially carcinogenic
Enzymes that act against microorganisms are called?
Antimicrobial enzymes
Example of a antimicrobial enzyme.
lysozyme and prionzyme
What is used to reduce the number of bacteria in cheese?
lysozyme
What are typically used for treatment of disease. Ex: antibiotics
Antimicrobials
Antimicrobial soaps should be reserved for limited applications:
Handling food
care of newborns and high-risk patients by healthcare workers
CDC recommends washing hand in soap for how long?
10-15 seconds
Which ingredient do you want to avoid in antibacterial soaps?
triclosan
What is a good method to use when you don’t want to use chemicals?
Steam cleaners
How do steam cleaners work?
Heating up water to temperatures of about 248 degrees F- kills about 99% of bacteria, viruses, mold, and household dust mites.
