Exam 2 Controlling Microbial Growth in the Environment Flashcards
Removal or destruction of ALL microbes, including viruses and bacterial endospores, in or on an object
Sterilization
An environment or procedure that is free of contamination by pathogens
Aseptic
Use of physical or chemical agents known as disinfectants; DOES NOT guarantee all pathogens are eliminated
Disinfection
When a chemical is used on skin or other tissue
Antisepsis/antiseptic
Removal of microbes from a surface by scrubbing
Degerming
Process of disinfecting places and utensils used by the public
Sanitization
Use of heat to kill pathogens and reduce the number of spoilage microorganisms in food and beverages
Pasteurization
-stasis/-static
Chemical or physical agent inhibits microbial metabolism and growth
-cide/-cidal
Agents that destroy or permanently inactivate a particular type of microbe
Permanent loss of reproductive ability under ideal environmental conditions
Microbial death
Measurement of efficacy of an antimicrobial agent
Microbial death rate
What are the 2 main actions of antimicrobial agents?
Alteration of cell walls and membranes
Damage to proteins and nucleic acids
Characteristics of ideal antimicrobial agents
Inexpensive
Fast
Stable
Selective toxicity
Control microbial growth but harmless to humans, animals, and objects
Selective toxicity
These are the most resistant microorganisms to kill
Prions and endospores
These bacteria are the easiest to kill
Gram (+) bacteria
Why are Gram (-) bacteria more resistant than Gram (+)?
They have 2 layers in the cell
More r plasmids (resistance)
This level of germicide kills ALL pathogens, including endospores (sterilization)
High-level
This level of germicide kills fungal spores, protozoan cysts, viruses, and pathogenic bacteria (disinfect instruments)
Intermediate-level
This level of germicide eliminates vegetative bacteria, fungi, protozoa, and some viruses (disinfect skin)
Low-level
What are the ideal conditions for antimicrobial?
Warm acidic conditions
What are 4 methods of moist heat?
Boiling
Autoclaving
Pasteurization
Ultrahigh-temp sterilization
Endospores, prions, protozoan cysts, and some viruses can survive this method of moist heat
Boiling
This is the best method of moist heat for sterilization
Autoclaving (pressure applied which prevents steam from escaping)
This method of moist heat is used for milk, ice cream, yogurt and fruit juices but does not sterilize
Pasteurization
This method of moist heat allows treated liquids to be stored at room temperature and has a shelf life of 6-9 months until open
Ultrahigh-temperature sterilization
This is the ultimate means of sterilization
Incineration
What are 2 methods of dry heat?
Hot air
Incineration
This halts the growth of most pathogens with the exception of Listeria and Yersinia
Refrigeration
Drying inhibits growth due to removal of water
Dessication
Used for long-term preservation of microbial cultures
Lyophilization (freeze drying)
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 foods to inhibit growth
Osmotic pressure
Fungi have greater ability than bacteria to survive what type of osmotic conditions?
Hypertonic conditions
This form of radiation is effective at killing but does not penetrate well
Electron beams
This form of radiation penetrates well but requires hours to kill microbes; also prevents overripening of foods
Gamma rays
This is a form of non-ionizing radiation that does not penetrate well but is suitable for disinfecting air, transparent fluids, and surfaces of object
UV light
This method of microbial control is often more effective against enveloped viruses and vegetative cells of bacteria, fungi, and protozoa
Chemical methods
Chemical method that is an intermediate-low level disinfectant such as Lysol and pine-sol
Phenol and phenolics
Chemical method that is an intermediate level disinfectant that is more effective than soap in removing bacteria from hands
Alcohols
Chemical method that is an intermediate-level antimicrobial chemical including iodine, chlorine, bromine, fluorine
Halogens
This halogen is used in preparation for surgery and is also in combination with a detergent
Iodophores (betadine)
This chemical method is a high-level disinfectant including peroxides, ozone, and peracetic acid
Oxidizing agents
Why should we not use hydrogen peroxide in wound care?
Cytotoxic to healthy cells and granulating tissues
What should we use to clean wounds?
Normal saline
Commercial wound cleansers
This chemical method includes soap and detergents
Surfactants
These are good at degerming agents but not antimicrobial
Soap
These are low-level disinfectants that include Quats
Detergents
How should we disinfect adjusting tables?
Clean excess dirt first
Wipe surface
Must be visibly wet for 4 minutes
Let air dry
