88 notecards = 22 pages (4 cards per page)
___________ is rapidly becoming the most popular team in the hospital. Who does it include?
Infection control team
acquired in the hospital
What is the worst method for washing one’s hands?
Waterless, alcohol based hand wipes
What actually removes the bacteria while washing your hands?
The friction of you moving your hands back and forth.
The destruction or removal of all microbial life, including endospores.
Any treatment used on inanimate objects to kill or inhibit the growth of microorganisms; removing pathogens. Doesn't kill spores.
The removal of microorganisms from eating utensils and food preparation areas.
to make (an object or area) safe for unprotected personnel by removing, neutralizing, or destroying any harmful substance, as radioactive material or poisonous gas
We wish to control microbes under these two conditions
1. Destroy and reduce the transmission of pathogens
the removal of microorganisms from an area
infected with a toxic or pathogenic organism in the blood or tissue, especially in respiratory or urinary tracts
free from pathogenic organisms (especially on skin) that cause disease or infection
2 main chemical disinfecting agents that kill microorganisms or inhibit their growth
1. - cides
agents which kill microbes
Stops microbes from growing but do not kill them. The microbes are there and if you take the treatment away, they can resume growth.
kill microorganisms and viruses, but not necessarily endospores
Alcohol kills microbes best at what %?
protective structure to endure environmental stress
Most resistant organism to being killed
Microbes are considered to be dead when ______
they are unable to reproduce in conditions that normally support their reproduction
How do microbes die?
When you spray down a counter top, they're not all killed immediately.
The population will be reduced by the same fraction in each time interval
Decimal reduction value. Also called D process.
1 D-process reduces the number of microbes by ______
Where you set up microbes in liquid culture and add to that culture different concentrations of your test disinfectant. Determine MIC or MBC.
Minimum inhibitory concentration. What is the minimum dose we need to have to prevent microbial growth> Doesn’t tell you one particular aspect: did we kill the microbes or did we just stop them from growing?
After MIC, the second step you can do as an add on is take the cultures that don’t look like they have microbes growing in them and dilute them into fresh media so its been diluted down to where the disinfectant is not going to work and we will see if the microbe grows back. Then we can determine the concentration we need to kill the microbes. Not just make sure it slows down and stops growing but gets killed.
how much can you dilute it?
5 disinfectant considerations
1. Dilution factor
Time of exposure
How long does it take for you to kill off the microbes? If you have to wipe down the counter for 30 minutes, its not useful.
Target of microbes
Making sure it kills the microbes you care about.
Surfaces of interest
Making sure it doesn’t degrade or have nasty effects on to whatever surface.
We use the size of that zone of inhibition to compare how effective different disinfectants are on killing any one microbe.
2 chemical control agents
2 gas control agents
3 liquid control agents
3 methods of mechanical control
2 types of filtration sterlization
2 physical control agents
2 types of radiation control agents
2 types of heat control
uses x-rays and gamma rays to sterilize
How does ionizing radiation work?
strips electrons from atoms
what two byproducts does ionizing radiation produce?
1. Superoxide free radicals
uses UV rays to disinfect
2 forms of dry heat control
2 types of moist heat control
1. sterilization (steam under pressure)
2 physical removal agents
breaks water surface tension
Emulsifies all hydrophobic lipids and fats so that you can physically remove the microbes from hands.
"savior of mothers"
He wore to surgery:
4 methods using heat and moisture
1. autoclave - true sterilization
Autoclave used to sterilize using pressurized steam
Autoclave achieves sterilization at ___°C and ___psi in ____minutes
Pasteur developed to avoid spoilage of wine
(High temperature short-term – HTST)
ultra high temperature pasteurization
Not as effective as moist heat
Oxidizes cell to ashes
Why is UV radiation limited to surface sterilization?
Limited to surface sterilization because UV radiation does not penetrate glass, dirt films, and other substances
99.9-99.99% effective against E. coli on leafy greens
ionizing radiation is used for sterilizing what?
Gamma radiation used for sterilization and pasteurization of antibiotics, hormones, sutures, plastic disposable supplies, and food
nonionizing radiation is used for what?
Used to destroy microbes in air, drinking water and surfaces
main sterilizing gas
How does sterilizing gas work?
Destroys microbes including endospores and viruses
What is sterilizing gas used to sterilize?
Used to sterilize heat- or moisture- sensitive materials
what is the down side to using sterilizing gas?
Mutagenic and potentially carcinogenic
What are the vital targets for chemical microbial killing? (5)
1. Proteins (enzymes) - target its function, denature
3 main chemical methods of killing
1. disruption of plasma membrane
How do phenols work?
Act by denaturing proteins and disrupting cell membranes
Examples of phenols
4 main types of protein denaturation
How does alcohol work as a chemical method of killing microbes?
Solutions of 60% - 80% isopropyl or ethyl alcohol kill vegetative bacteria and fungi. effective against mycobacteria.
2 limitations to using alcohol as a chemical method of killing microbes
1. Evaporates quickly, limiting contact time
How do heavy metals work as a chemical method of killing microbes?
e.g. Ions of mercury, silver, arsenic, zinc, and copper
How does ammonia work as a chemical method of killing microbes?
It denatures proteins. Common in hospitals as detergent and denaturant. Pseudomonas bacteria causes infections in burn patients and in contact lens wearers. This bacteria has developed resistance against ammonia compounds.
2 main types of oxidation used in chemical microbial killing
1. halogens (iodine and chlorine)
How does hydrogen peroxide function as a chemical microbial killing agent?
Powerful oxidizing agent
transfers electrons from one to another to break down physical components
How halogens work at killing microbes
Oxidize proteins and other cell components
How is iodine used as a chemical microbial killer?
Kills vegetative cells but not reliable with endospores
How is chlorine used as a chemical microbial killer?
8 points to consider in choosing a chemical microbial killer
1. Highly effective - Fast acting, even when dilute, have a broad range of activity over various environmental conditions, soluble and active in both water and oils