Module 5 - Control of Micro-Organisms Flashcards
(35 cards)
Explain sterilization vs disinfection
Sterilization is the removal of all viable organisms, spores, and acellular entities such as viruses. Disinfection kills, inhibits, or removes microorganisms, but not spores.
How does sanitization differ from sterilization or disinfection
It reduces microbial populations to safe levels based on public health standards, usually for living tissues
What is chemotherapy
Use of chemical agents to kill or inhibit the growth of microorganisms within host tissue
What are Cidal Agents
Kill pathogens, bactericide, fungicide, viricide, etc.
What are static agents
Prevent growth when present, bacteriostatic, fungistatic
How does antisepsis differ from sterilization and disinfection
Agents that prevent infection, while destroying or inhibiting microorganisms on living tissues. Can be used on tissues
What is a bacterial endospore
Dormant stage that provides protection against numerous conditions such as heat, radiation, chemicals, and desiccation
Explain the pattern of microbial death
Microbial populations are not killed instantly, but rather exponentially
What is decimal reduction time (D)
Time required to kill 90% of microbes/spores under specified conditions
What is the Z value
The measure of the temperature sensitivity of an organism
Name the 3 types of physical control methods
-Heat (dry / moist)
-Filtration (air / liquid)
-Radiation
Name the 3 types of chemical control methods
-Disinfectants
-Antiseptics
-Chemotherapy
What is an autoclave
A machine that sterilizes using very hot steam under pressure
What is pasteurization
Used for milk, beer, and other beverages. Kills pathogens and reduces load of organisms, but does not sterilize.
Flash - 15 seconds at 72C
Ultrahigh - 3 seconds at 150C
How does low temperature affect microorganisms
Stops reproduction (no water)
Some killed by ice crystals
Slows cell growth
How does dry heat sterilization differ from moist
Requires higher temperatures and longer exposure times, but it prevents corrosion
What is ethylene oxide used for
Used for disposable, heat sensitive materials
Explain types of dosage and the related ratio
Therapeutic - Level required for clinical
Toxic - Level at which drug becomes toxic
Therapeutic Index - Ratio of toxic dos to therapeutic dose
Explain two types of drug spectrum
Narrow - attacks a few different pathogens
Broad - attack many different pathogens
Explain two types of action agents
Cidal - kills microbes
Static - inhibits growth of microbes
Name a protein inhibitor and a cell wall inhibitor and explain how they work
Penicillin - prevent cross-linking of peptidoglycan
Aminoglycosides - inhibit a step in protein synthesis, bind to 30S ribosomal subunit
Name 6 types of drug resistance
- Alteration of enzyme or organelle
- Inactivation of drug by degradation
- Inactivation or drug by modification
- Pump out drug
- Prevent cell entry
- Use alternate pathways to increase production of target metabolite
What materials can be sterilized by filtration
Liquids, gasses, and heat sensitive
What materials can be sterilized by UV
ONLY DISINFECTION Surface treatment of work stations, water treatment
NOT glass
