Microbial Control Physical Methods Flashcards
what is sterilization
removal or destruction of ALL microbes, including viruses and bacterial endospores, in or on an object
what is aseptic
an environment or procedure that is free of contamination by pathogens
what is disinfection
use of physical or chemical agents known as DISINFECTANTS to inhibit or destroy microorganisms
DOES NOT guarentee that ALL pathogens are eliminated
what is Antisepsis/antiseptic
when a chemical is USED ON SKIN OR OTHER TISSUE the process is called ANTISEPSIS and the chemical is called ANTISEPTIC
what is degerming
removal of microbes from a surface by SCRUBBING
what is sanitization
process of disinfecting places and utensils USED BY THE PUBLIC to reduce the number of pathogenic microbes to meet accepted health standards
what is pasteurizaiton
use of heat to kill pathogens and reduce the number of spoilage microogranisms in FOOD AND BEVERAGES
what is stasis/static
suffixes to indicate that a chemical or physical agent INHIBITS microbial metabolism and growth
what is cide/cidal
refers to agents that DESTROY OR PERMANENTLY INACTIVATE a particular type of microbe
what is microbial death
PERMANENT LOSS OF REPORDUCTIVE ABILITY under ideal environmental conditions
what are the 2 actions of antimicrobial agents
alteration of cell walls and membranes
damage to proteins and nucleic acids
what are the factors affecting the efficiency of antimicrobial agents
where u need to treat it, and the susceptibility of microorganisms
Most resistant to microbial agents
prions and bacterial endospores
Least resistant to microbial agents
enveloped viruses, most gram-positive bacteria
why are Gram - bacteria more resistant to antimicrobials
they have a double phospholipid bilayer and have more R plasmids
whats more effective moist or dry heat?
Moist heat
Methods of moist heat?
boiling
autoclaving
pasteurization
ultrahigh-temperature sterilization
Time is critical and endospores, prions, protozoan cysts, and some viruses can survive this type of heat
Boiling
True or False Pasteurization is sterilization
FALSE, its not sterilization
Ultra temperature sterilization
treated liquids can be stored at room temperature, normal shelf life 6-9 months
facts of Dry heat
hot air and incineration
Requires higher temperatures for a longer time
incineration is ULTIMATE means of sterilization
what are the exceptions of bacteria that can live through refrigeration/ freezing
Listeria, Yersinia
what is dessication
drying inhibits growth due to removal of water
what is lyophilization
aka freeze drying. used for long term preservation of microbial cultures, prevents formation of damaging ice crystals
what is filtration
PASSAGE OF A FLUID THROUGH A SIEVE DESIGNED TO TRAP PARTICLES and seperate them from the fluid
what is osmotic pressure
HIGH CONCENTRATIONS OF SALT OR SUGAR in food to inhibit growth
Cells in hypertonic solution of salt or sugar lose wate and cell crenates
FUNGI HAVE GREATER ABILITY than bacteria to survive
what is ionizing radiation
Electron Beams- effective at killing but do not penetrate well
Gamma rays- penetrate well but require hours to kill microbes
what is nonionizing radiation
UV light, but does not penetrate well
how to increase shelf life of food achieved by….
Ionizing radiation (gamma rays) ex. strawberries
