Antimicrobial Resistance Flashcards
What are the 3 ways of physical sterilization?
Heat
Radiation
Filter
What “metric” quantitfies antimicrobial effectiveness?
- Decimal Reduction time - time it takes to reduce microbial population by 90%
- D = -t / log Nf - log No
- T = Tfinal - Tinitial
- What is the most widely used method of controlling microbial growth?
- How does this method work against microbes?
- Heat sterilization
- High temperatures denature macromolecules
What are some things you can’t kill/sterilize in an autoclave?
- spores
- Anything you want to keep living
- Scrubs, electronics, etc.
How does an autoclave work?
- Sealed device that use steam under pressure
- allows temps of water to get above 100 C
- Pressure doesnt kill, but high temperature does.
What is pasteurization?
Is pasteurization a form of sterilization?
- process of using precisely controlled heat to reduce the microbial load in heat-sensitive liquids
- Does not kill all organisms - so technically it is not sterilization.
What types of surfaces can/can’t be affected by UV radiation?
- Can
- tops of surfaces
- Can’t
- solid, opaque, or light-absorbing surfaces
Is radiation sterilization approved by the WHO for the decontamination of foods susceptible to microbial contamination?
Yes
What is filter sterilization good for?
- Allow liquid and gas to fit through but catches very small microbes
- Good for heat sensitive things that need to be sterilized.
Most bacteria are [] - [] microns long, but HEPA filters catch anything greater than [] um….
- 3-5 microns
- >.3 um
What is the MAIN target for most antimicrobials?
essential proteins and cell membrane
What species of bacteria make 2/3 of the useful antibiotics?
Streptomyces species
What are the 3 main compounds produced to stop the growth of microbes?
Antibacterials
Antivirals
Antifungus
What is the minimum inhibitory concentration?
- Smallest amount of an agent needed to inhibit growth of a microorganism
- Varies between organism, not real precies
How are viable cell counts used to quantify chemical growth control of microbes?
What is the draw back to viable cell count?
- Gives information about bacteriostatic / cidal /lytic
- since you actually look at the plates and shit
- Can be used to calculate decimal reduction times
- However, can be very laborious