Microbial Control Flashcards
Joseph Lister (1827-1912)
He promoted the idea of ? in surgery using ? acid (phenol) as an antiseptic.
In which other settings do we need MICROBIAL CONTROL?
? transmission
? spoilage
Joseph Lister (1827-1912)
He promoted the idea of sterilization in surgery using carbolic acid (phenol) as an antiseptic.
In which other settings do we need MICROBIAL CONTROL?
Disease transmission
Food spoilage
Factors that influence the microbial control:
▪ ? of microorganisms
▪ ? of microorganisms
▪ ? of agent
▪ Presence of ? material (easier to kill when lesser organic material)
▪ ? of the material
▪ ?
▪ Temperature
▪ pH
▪ ?
Factors that influence the microbial control:
▪ number of microorganisms
▪ type of microorganisms (so a gram negative bacteria will be more susceptible for control than a gram + ? while gram + more susceptible than mycoacteria BUT ENDOSPORE HARDEST TO CONTROL - highest resistant or configuration of cell.)
▪ concentration of agent (Now working with bleach of 0.02% versus 20% of bleach)
▪ Presence of organic material (easier to kill when lesser organic material e.g. bleach will not do anything to kill pathogen)
▪ composition of the material (We will have different options for the steel and for the plastic less.)
▪ time
▪ Temperature
▪ pH
▪ biofilms
ORDER: Hardest to kill to easiest to kill
BACTERIAL spores
protozoa with cysts
mycobacteria
non-enveloped viruses
fungi
vegetative bacteria
enveloped viruses (coronavirus) -> envelope eaisly breaks; sensitive bacteria
Outcomes of microbial control:
▪ Sterilization: eradication of all viable microorganisms including ?
▪ Disinfection: eradiation of ? microbial life (reduce the numbers… except ?)
▪ Antisepsis: disinfection of living ? (kills or inhibits growth of ?)
▪ Decontamination: treatment of ? surface to make it safe to handle
Outcomes of microbial control:
▪ Sterilization: the eradication of all viable microorganisms including spores
▪ Disinfection: eradication of most microbial life (reduce the numbers… except ?)
▪ Antisepsis: disinfection of living tissue (kills or inhibits growth of bacteria)
▪ Decontamination: treatment of inanimate (not alive) surface to make it safe to handle
STERILIZATION:
Process to * ? * microorganisms and their pathogenic products (including ** ? **), usually on equipment and for surgical procedures.
? (moist heat)
?
?
? flame
? irradiation
?-light (UV-C)
? sterilization
? filtration
STERILIZATION
Process to eliminate or kill all forms of living microorganisms and their
pathogenic products (including spores), usually on equipment and for surgical procedures.
Autoclaving (moist heat)
Dry heat
Incineration
Alcohol flame
Gamma irradiation
UV-light (UV-C)
Chemical sterilization
Membrane filtration
AUTOCLAVING
Steam (moist) under pressure (121 degree C, 15 min) Sterilization of culture media (solid and liquid), ? items, and ? equipment.
(note cant use autoclave if need to keep sum dry as its gets moist for e.g. a ? -> w/ humid gets damaged)
Hot air oven (dry heat)
High temperature (160 degree C, 2-4h) Sterilization of ?-resistant equipment and ? glassware. Sterilization of ? and ?
(note: here opposite than autoclaving then here it will be dry so cannot use sum that has to stay in liquid form)
Incineration
Ultrahigh temperature (1000 degree C) -> used for sum that we need to discard
Destroy contaminated materials
Flaming
Sterilization of ? utensils. Alternative is dipping of objects in 70% ethanol and briefly touch open burner flame
AUTOCLAVING
Steam (moist) under pressure (121 degree C, 15 min) Sterilization of culture media (solid and liquid), laboratory items and surgical equipment.
(note cant use autoclave if need to keep sum dry as its gets moist for e.g. a membrane -> w/ humid gets damaged)
Hot air oven (dry heat)
High temperature (160 degree C, 2-4h) Sterilization of heat-resistant equipment and dry glassware. Sterilization of oils and powders
(note: here opposite than autoclaving then here it will be dry so cannot use sum that has to be stay in luquid form)
Incineration
Ultrahigh temperature (1000 degree C) -> used for sum that we need to discard
Destroy contaminated materials
Flaming
Sterilization of small utensils Alternative is dipping of objects in 70% ethanol and briefly touch open burner flame
Heat kills living things by denaturing these essential proteins.
As the temperature rises, the ? bonds that keep protein structures together start to break, followed by the ? bonds with rising temperatures.
Extreme environmental (temp., pH) disrupt protein ? and ?.
Heat kills living things by denaturing these essential proteins.
As the temperature rises, the weakest bonds that keep protein structures together start to break, followed by the stronger bonds with rising temperatures.
Extreme environmental (temp., pH) disrupt protein shape and function.
STERILIZATION WITH CHEMICALS
Gamma irradiation (ionizing radiation) kills living organisms by breaking down ?, inhibiting ?. It can penetrate ? structures (thickness dependence).
UV light (UV-C) breaks down certain chemical bonds and scrambles the structure of ?, ? and ?, causing a microorganism to be unable to ?.
STERILIZATION WITH CHEMICALS
Gamma irradiation (ionizing radiation) kills living organisms by breaking down DNA, inhibiting division. It can penetrate inanimate structures (thickness dependence)
- gamma is the most powerful on the electromagnetic spectrum (highest energy)
UV light (UV-C specificially) with time breaks down certain chemical bonds and scrambles the structure of DNA, RNA and proteins, causing a microorganism to be unable to multiply
- UV rays falls between ionizing and non-ionizing radiation but still v close to ionizing
Then we have chemical sterilization can be with GASES or by LIQUID:
Gaseous sterilization commonly used:
ethylene oxide
formaldehyde
nitrogen dioxide
ozone.
Liquid sterilization commonly used:
(hydrogen peroxide
Glutaraldehyde
hypochlorite)
Appropriate for heat-sensitive materials like plastics, fiber optics, and biological specimens. It is crucial to ensure that the materials undergoing sterilization are compatible with the chemical being used.
Treated Articles need to undergo a process of desorption to remove the toxic residual wastes. (if immerse in liquid then will have to deal it with later on as contaminants stays in that luquid)
Filtration is unique among sterilization techniques in that it ?, rather than ?, microorganisms.
The primary mechanisms involved in filtration are ?, ?, and ? within the matrix of the filter.
Filtration is unique among sterilization techniques in that it removes, rather than destroys, microorganisms.
The primary mechanisms involved in filtration are sieving, adsorption, and trapping within the matrix of the filter.
(Penetration or yeah of those living things is really is for instance the example of the liquid media or medium that contains meant plenty of amino acid. So you can sterilize that with this and put it in the autoclave because maybe it’s too much for the composition of the medium.
So you can filter very easily and rapidly with a vacuum, a liquid just put it on top and a few seconds after you pass it through the membrane, the filter.
Prions
The term “prions” refers to abnormal, pathogenic proteins that are transmissible and can induce abnormal folding of specific normal cellular proteins, most abundantly in the BRAIN.
The functions of these normal prion proteins are still not completely understood.
Prions are not considered a ? organism.
” Transmissible Spongiform encephalopathy “
encephalopathy means brain disease (brain tissue looks like a sponge after biopsy)
v rare to see prions these days (mad cow disease: cannibalism; Papau and Guinea cannabalism resistant to this)
living organism
Rare disease but still protocols put to eliminate PRIONS
** Special sterilization procedures: **
* ? (NaOH, 1N) immersion + ? (121° C)
* high-temperature autoclaving of #?° C for ? hour/s
* High-temperature autoclaving of #?° C for ? minutes.
Current guidelines recommend that only critical items that will be in contact with * ? * (e.g., brain, spinal cord, eye tissue) should undergo special ? ? sterilization procedures.
Rare disease but still protocols put to eliminate PRIONS
** Special sterilization procedures: **
* Sodium hydroxide (NaOH, 1N) immersion + autoclaving (121° C)
* high-temperature autoclaving of 132° C for 1 hour.
* High-temperature autoclaving of 134° C for 18 minutes.
Current guidelines recommend that only critical items that will be in contact with * neurologic tissue * (e.g., brain, spinal cord, eye tissue) should undergo special prion inactivation sterilization procedures.
DISINFECTION
Disinfection involves the destruction of microorganisms, but not usually ?, on inanimate surfaces or objects. Disinfection is not ?.
Both disinfection and sterilization remove pathogens. The key to distinguishing the two techniques is the bacterial spore. Removing pathogens but leaving endospores is considered ?, while destroying both spores and pathogens is considered ?.
SO boiling water 100 degree C would only disinfect and not kill spores so NOT sterilization
UV light, less time or type “ A and B “, which are less powerful as well, etc. (C is more powerful than A and B)
THUS BOILING WATER, UV A & B, CHEMICAL DISINFECTION, MEMBRANE FILTRATION -> all will only lead to disinfection and not STERILIZATION!
DISINFECTION
Disinfection involves the destruction of microorganisms, but not usually spores, on inanimate surfaces or objects. Disinfection is not STERILIZATION!
Both disinfection and sterilization remove pathogens. The key to distinguishing the two techniques is the bacterial spore. Removing pathogens but leaving endospores is considered disinfection while destroying both spores and pathogens is considered STERILIZATION
SO boiling water 100 degrees C would only disinfect and not kill spores so NOT sterilization
UV light, less time or type “ A and B “, which are less powerful as well, etc. (C is more powerful than A and B)
PASTEURIZATION
This process kills the heat-susceptible organisms. This process is used very commonly for milk.
Pasteurization:
High temperature (72 C, 25 sec)
Rapidly heating liquids (food) to slow microbial growth. Taste of food remains the same!
Ultra-high temperature pasteurization 138°C for 2 sec. Eliminates a large proportion of potential spoilage organisms and thus extend shelf-life
High heat-resistance spores may survive the treatment but spores will survive as not enough time (2 secs)
PASTEURIZATION
This process kills the heat-susceptible organisms. This process is used very commonly for milk.
Pasterurization:
High temperature (72 C, 25 sec)
Rapidly heating liquids (food) to slow microbial growth. Taste of food remains the same!
Ultra-high temperature pasteurization 138°C for 2 sec. Eliminates a large proportion of potential spoilage organisms and thus extends shelf-life
High heat-resistance spores may survive the treatment.
ANTISEPSIS
Antisepsis is defined as the ? or ? of micro-organisms on living tissues, thereby limiting or preventing the harmful results of ?.
Different types of microbial control methods
PHYSICAL:
heat, ?, desiccation, ?, filtration
cold and desiccation -> freezing and ? respectively ** prevent multiplication but do not remove ? **
CHEMICAL:
gases
? (animate, inanimate)
(the blue sign means that its the maximum temprature it can reach etc.)
Maximum outcomes of microbial control: Sterilization
Disinfection
Antisepsis
Decontamination
Antisepsis is defined as the destruction or inhibition of micro-organisms on living tissues, thereby limiting or preventing the harmful results of infection.
