Microbiology Unit 3 Flashcards
Sterilization
Destruction or removal of all viable microorganisms (including endospores and viruses); absolute
Decontamination
Removal of organic matter off surfaces (Ex. wiping off the counter after eating)
Disinfection
killing, inhibiting, or removal of pathogenic microorganisms
Disinfectants
used on inanimate objects
Sanitization
reduction of microbial population to levels deemed safe (based on public health standards)
Antisepsis
prevention of infection of living tissue (can be seen on the back of hand sanitizers)
Antiseptics (germicides)
chemical agents that kill or inhibit growth of microorganisms when applied to tissue
Chemotherapy
use of chemicals to kill or inhibit growth of microorganisms within host tissue
Moist Heat
method of destroying bacteria, fungi, and viruses; better penetration power because it uses water
Boiling
part of Moist Heat; will not always destroy endospores so does not necessarily sterilize
Pasteurization
part of Moist Heat; controlled heating at temperatures well below boiling; used for wine, milk, and other beverages
Which moist heat method kills pathogens present and slows spoilage?
pasteurization
Autoclave
part of Moist Heat; effective against all types of microbes (sterilization)
What temperature, in degrees Celsius, must be reached in an autoclave to effectively sterilize?
121
True or False: Autoclave time for endospores is the same as for vegetative cells.
False
Dry Heat Sterilization
less effective than moist heat sterilization; requires higher temperatures and longer exposure times; items subjected to 160-170 degrees C for 2 to 3 hours
Flaming
a method of dry heat sterilization (used in lab)
Freezing
stops microbial reproduction due to lack of liquid water; some microorganisms can die by ice crystal disruption of the cell membrane
What temperature is generally required for the freezing method?
-20 degrees C
Refrigeration
slows microbial growth and reproduction
What temperature is generally required for refrigeration (slowing of microbial growth and reproduction)?
4 degrees C
Ultraviolet (UV) Radiation
non-ionizing radiation; causes thymine dimers in DNA; has poor penetrating power and is limited to disinfection of surfaces, air, and water
Ionizing Radiation
beta, gamma, X-rays; penetrates deep into objects
Filtration
reduces microbial populations; sterilization of heat-sensitive solutions; uses membrane filter with defined pore size and also used for air
Antimicrobial agent
natural or synthetic chemical that kills or inhibits growth of microbes
-cidal
suffix indicating a chemical agent that kills pathogens and many-nonpathogens, but not necessarily endospores
-static
suffix indicating a chemical agent that inhibits growth
Minimal Inhibitory Concentration (MIC)
`lowest concentration of drug that inhibits growth of pathogen
Minimal Lethal Concentration (MLC)
lowest concentration of drug that kills pathogen
Dilution Susceptibility Test
used to detect the smallest amount of agent needed to inhibit the growth of a test organism and the broth from which a microbe cant be recovered
In the Dilution Susceptibility Test, which concentration is in the first two tubes with minimum turbidity?
MIC
In the Disk Diffusion Tests, what does the line between growth and no growth mean?
MIC
What are the factors influencing the effectiveness of an antimicrobial agent?
population size, population composition, concentration or intensity of the agent, duration of exposure, temperature, and local environment
Kirby-Bauer Method
used to determine the effectiveness of certain antimicrobials; relationship between zone diameter and degree of microbial resistance
Antigen
any molecule or substance that stimulates the immune system to make antibodies against it and activates immune memory
Vaccine
substance given to a host (usually by injection) that induces artificial active immunity (acts as an antigen, but doesn’t cause disease)
Vaccination/Immunization
inoculation of a host with a vaccine to stimulate protective immunity; sometimes a booster is required to enhance/restore protection