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Flashcards in Control of Microbial Population Deck (46)
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What is Ebers Papyrus

ancient document showing that people of ancient times were interested in how to treat diseases

document had tx for everything under the sun


Who is Paul Ehrlich

popularized the concept of magic bullet and also invented first tx for syphilis thereby initiating and naming the concept of chemotherapy


Who is Alexander Fleming

rediscovered penicillin

left petri dishes over night and noticed where fungi was growing, there was no bacteria


Who is Gerhard Domagk

red azo dyes --> compound will kill bacteria

prontonsil --> first antibiotic


what are the two methods of microbial control

physical and chemical


difference between physical and chemical methods for microbial control

physical: high temp (moist heat, pasteurization, dry heat), low temp, radiation, filtration, ethylene oxide gas

chemical: food preservatives, disinfectants, antiseptics, antibiotics, antifungals, antivirals


what roadmap does one use to go about deciding how to control microbes

what is it?
where is it?
what do you need to achieve?


Given streptococcus pyogenes as an example, use the roadmap to decide how you would go about controlling it

what is it? - streptococcus pyogenes
where is it? - living tissue (soft tissues of arms)
what do you need to achieve? - inhibition of growth


what microbe is most resistant to disinfectant and antiseptic agents

bacterial spores


what agent is successful at killing all the microbes which includes bacteria, virus, fungus, bacterial endospores, mycobacteria

formaldehyde and glutaraldehyde


difference between disinfectants and antiseptics

disinfectants tends to be used on hard surfaces while antiseptics can be used on living tissue like our skin and such


what agent can be used as both a disinfectant and an antiseptic

iodophors and alcohol

hence these two can be used on hard surfaces and living tissue


what microorganism is resistant to a lot of antiseptics and disinfectants

bacterial spores


what does it mean that bacterial spores have inherent resistance

endospore formation of a biofilm or a structural component of cell such as a waxy coating or outer membrane is where these microorganisms get their resistance from (AKA their resistance is not acquire rather it is innate)


what is meant by acquired resistance

microorganism building a resistance to an antiseptic or disinfectant agent due to multiple exposure (AKA it is not innate)


most resistant microorganisms

prions --> endospores --> mycobacteria


most susceptible microorganisms

enveloped virus --> gram pos bacteria --->large non enveloped viruses


NOT SURE HOW IMPO THIS IS but list the organisms from most resistant to most susceptible

prion --> endospores --> mycobacteria --> small non enveloped viruses --> fungal spores --> gram neg viruses --> vegetative fungi --> large non enveloped viruses --> gram pos bacteria --> enveloped viruses



what does the number of microorganisms influence

tx type, duration, conc etc


what is the difference in time of inactivation in a bacteria vs. a bacterial endospore

it takes longer to kill those with an endospore and might take a higher conc of tx and even possibly a diff tx


give an example of a gram neg and a gram pos bacteria

gram neg - E. coli
gram pos - S. aureus


how does the MIC (minimum inhibitory concentration) differ in E. coli vs. S. aureus?

since E. coli is a gram neg bacteria, it takes higher MIC to inhibit its growth


what are some goals to achieve when it comes to microbes

-reducing microbial numbers to sanitary/acceptable levels
-slow down or inhibit microbial growth
-kill microorganism
-prevention vs. treatment


what is used to reduce microbial numbers to sanitary/acceptable levels



what is the process called when killing microorganisms



what is difference in prevention vs. treatment

in prevention, antiseptics and disinfectants are used

in tx, therapeutic antibiotics are used


most effective liquid sterilant available

peracetic acid


why is peracetic acid considered so effective

kills endospores and viruses in 30 mins
kills bacteria and fungi in less than 5 mins
kills most microorganisms


what are some advantages of peracetic acid

no toxic residue
minimally affected by organic matter


what is peracetic acid actually used for

high level disinfection for eg heat or steam sensitive instruments for invasive procedures