Microbial Control Flashcards
What is sterilization
The killing or removal of ALL viable organisms ( including endospores)
Is clean and sterilized is the same
Hands can be clean, but not sterile
The cloth coming from autoclave can be dirty, but sterile
What is inhibition
Effectively limit microbial growth. We are not necessarily killing them. We just stop them from multiplying
What is decontamination
The treatment of an object to make it safe to handle ( removing food from the table)
What is disinfection
Directly targets the removal of all pathogens, not necessarily all microorganisms
Physical methods for antimicrobial control
Heat
Radiation
Filtration
Chemical methods for killing microbes are also called
Antimicrobes
What antimicrobes are used on external surfaces and internally
External: sterilants,disinfectants, antiseptics
Internally: antibiotics,antiviruls,antifungals
What is the most widely used physical control for controlling microorganisms
Heat
High temperatures ___ macromolecules
Denature
What is decimal reduction time?
Amount of time required to reduce viability tenfold ( from 100% to 10%)
The decimal reduction time is ___ correlated with the temperature
Inversely
The time necessary to kill a defined fraction is dependent of ____
The initial cell concentration
What will be the difference in decimal reduction time between mesophile and thermophile
Mesophile will have lower decimal time at lower temperatures, comparing to thermophile
What is the thermal death time
the time needed to kill all cells at a given temperature.
Thermal death time depends on
The population size of the microorganism tested, so you need to standardize the starting number of cells to be able to compare the sensitivity of different microorhanisms
What is the issue with endospores
They can resist the temperatures that will kill microorganisms. 5 min in boiling water for a decimal reduction
What is the autoclave
A sealed device that uses steam under pressure. it allows temperature of water to get above 100 C without boiling
What is the time and temperature for sterilization in autoclave
121 C in 10-15 minutes
What kills the microorganism in the autoclave
Not the pressure, but the temperature
What should you remember with autoclave and big objects
The object is a little colder than the environment and thus more time is required
What is Pasteurization
The process of using precisely controlled heat to reduce the microbial load in heat-sensitive liquids. It does not kill all microorganisms
What is the purpose of pasteurization?
Reduces the microbial load, increases the shelf life of the product
Pasteurization reduces what kinds of pathogens
Listeria monocytogenes Salmonella enterica Campylobacter E.coli Mycobacterium