Chapter 9 Flashcards
removal or destruction of all microbes in or on object
sterilization
environment or procedure that is free of contamination by pathogens
aseptic
does not guarantee that all pathogens are eliminated
disinfection
- only used on inanimate objects
when used on living tissue or skin
antiseptic
- less concentrated than disinfectants
Washing hands are example of…
degerming
is the process of disinfecting places and
utensils used by the public to reduce the number of pathogenic
microbes to meet accepted public health standards
sanitization
5 is the use of heat to kill pathogens and
reduce the number of spoilage microorganisms in food
pasteurization
to indicate that a chemical or physical
agent inhibits microbial metabolism and growth but does
not necessarily kill microbes
suffix of stasis or static
refer to
agents that destroy or permanently inactivate a particular type of microbe
-icide or icidal
Identify the three most resistant groups of microbes
and explain why they are resistant to many antimicrobial
agents.
■ Bacterial endospores. The endospores of Bacillus
and Clostridium are the most resilient forms
of life. They can survive environmental extremes of temperature,
acidity, and dryness and can withstand many
chemical disinfectants. For example, endospores have
survived more than 20 years in 70% alcohol, and scientists
have recovered viable endospores that were embalmed
with Egyptian mummies thousands of years ago.
■ Species of Mycobacterium. The cell walls of members of this genus, such as Mycobacterium tuberculosis, contain a large amount of a waxy lipid.
The wax allows these bacteria to survive drying and protects
them from most water-based chemicals; therefore, medical
personnel must use strong disinfectants or heat to treat whatever
comes into contact with tuberculosis patients, including
utensils, equipment, and patients’ rooms.
■ Cysts of protozoa. A protozoan cyst’s wall prevents entry
of most disinfectants, protects against drying, and shields
against radiation and heat.
Effect of temperature on efficacy of an antimicrobial chemical
more effective at a higher temperature
Describe five types of physical methods of microbial
control.
Physical methods of microbial control include exposure of the
microbes to extremes of heat and cold, desiccation, filtration, osmotic
pressure, and radiation.
consists of a pressure chamber, pipes to introduce
and evacuate steam, valves to remove air and control
pressure, and pressure and temperature gauges to monitor the procedure
Autoclave
another name for drying
desiccation
a technique
combining freezing and drying, to preserve microbes
lyophilization
