Session 9-16 Flashcards
What does growth mean for unicellular organisms
Growth for unicellular organisms means there is an increase in the number
What do you need for successful microbe cultivation
You need to know the nutritional requirements of the microbe. So a source of energy, mineral nutrients, and certain growth factors
What is a culture medium?
It is a solid or liquid substance that has the substances required for microbes to grow. It has water, a source of energy, mineral nutrients, and certain growth factors
What are the classes of culture media
Defined medium, complex or undefined medium, and differential culture medium
What is a differential culture medium?
It has an indicator that is normally a dye that will detect particular chemical reactions that happen during culture growth
What are some other factors that affect culture growth?
pH, temperature, and light
What is a liquid medium
It is a culture growth environment where all the things a microbe needs are inside a solvent. Microbes can grow super fast but it hard to identify them
What is a solid medium
It is an environment where all the things the microbe needs are in a liquid medium that has solidified Agar is a solidifying substance used in solid mediums
What is a solid medium
It is an environment where all the things the microbe needs are in a liquid medium that has solidified Agar is a solidifying substance used in solid mediums
What is Agar
Agar is a solid medium solidifier that is mixed into a liquid at high temperature then poured into sterile container where it solidifies the medium
What is a CFU and what does it stand for?
CFU stands for Colony Forming Unit which is the total number of microbial cells in a sample a cell is noted by the number of colonies on the culture
What’s the difference between pure culture and contaminated culture
A pure culture has one type of microbe in it while contaminated has multiple microbes on there
What is a biosafety cabinet
It protects the worker from the microbes being used as well as keeping the microbes inside the cabinet free from any other microbes so it can remain a pure culture
What are storage methods for microbial cultures
There are short term storages like laboratory fridges, and long term freeze-drying
What are the two microbes that cant grow on synthetic cultures
Viruses, and prions
If viruses cant be cultivated in synthetic cultures how are they cultivated
A host cell is first cultured then infected with viruses so that the viruses can replicate. When the host cell bursts the viruses that come out from it will form clusters known as plaques
What is decontamination
Decontamination is when materials have been rid of any microbes so that the materials are safe to handle
What is sterilization
Sterilization is killing all microbes present on an object
What is disinfection
Disinfection is killing some but not all microbes on a surface
What is pasteurization
It is when heat is used to kill microbes in milk to make it safe for ingesting
What are factors that affect microbial growth control
The surface or environment to which the microbes are on the meaning you won’t use the same decontamination tool for different surfaces and another would be the type of microbe ou are treating
What are the two categories of controlling microbe growth
Physical measures and chemical measures
What are the physical microbial control methods
Heat(dry heat, wet heat, incineration), radiation,
filtration,
What’s the difference between dry heat sterilization vs wet heat sterilization
Dry heat uses a lot of heat in a chamber to kill the microbes while wet heat is where microbes in an autoclave which uses steam and penetrate the microbes killing them
Why is pressure important in autoclaves
It allows for the temperature to reach that 100 degrees celsius as well as it causes the steam to penetrate the cellular structure of the microbes
What is incineration
Incineration is using very high temperatures that can reach up to 1000 degrees celsius used specifically for tools in contact with prions
What is radiation and what is it used for and what are its limitations?
Radiation refers to UV light or energy that is able to destroy genetic material. It is often used to decontaminate surfaces. It has low penetration power which is why its only used for surfaces
What is filtration
Filtration is when things are passed through a filter with pores too small for microbes to pass through to a certain target environment
What is cold sterilization
Cold sterilization is a form of chemical decontamination it uses deadly gases to sterilize objects
What are self disinfecting surfaces
They are surfaces made out of certain metals like copper and silver that can kill pathogens. Copper is able to react with oxygen radicals that can damage microbe DNA while silver can bind with cell walls destroying the cells.
What do static, lytic, and cidal refer to
They are suffixes for antimicrobial agents. Static is a drug that will inhibit the growth of the microbes so the population is static. Lytic suffix refers to the killing of microbial cells by degrading them. Cidal refers to the cells dying but the structure remains intact,
What are tetracyclines
They are antimicrobial drugs with 4 carbon rings
What is the mode of action of actinomycin
It makes sure the mRNA isn’t long enough for the cell to use it
What are growth factor analogs and what is an example
Growth factor analogs are similar to growth factors but do not function inside the cells it’s like eating fake food. Isozainid is an example of a growth factor analog that only works in mycobacteria
What are growth factor analogs and what is an example
Growth factor analogs are similar to growth factors but do not function inside the cells it’s like eating fake food. Isozainid is an example of a growth factor analog that only works in mycobacteria
What is the purpose of culturing microorganisms?
Since microorganisms normally can’t be studied in their natural habitat they need to be cultured to be studied more effectively
What are interferons
Interferons are proteins that stimulate antiviral proteins in uninfected cells
What are some things that antifungal drugs target?
Things like the fungal version of cholesterol (ergosterol), we can target the cell wall since human cells dint have a cell wall,
What is minimum inhibitory concentration
This is the minimum drug needed in order to inhibit the growth of the microbe
What is a zone of inhibition?
It is the space that is clear around the antimicrobial disc to where there are no microbes near so the greater the better
What are the short term solutions for antibiotic resistance
Using antimicrobial drugs only when they are needed, better education of physicians to properly prescribe drugs, combining drugs,
What is an example of a drug combination
B lactamase is a drug that some staphylococcus have grown resistant to because they have an enzyme that renders the drug useless so lactamase is combined with something that destroys the enzyme so that lactamase can affect the bacteria again
What are the long term solutions for drug resistance
Developing new antimicrobial drugs which are time-consuming and expensive or the less expensive solution of modifying current antimicrobial
What are bioinformatic tools
There are tools that can be used to design molecules to interact with specific microbial structures
What is nanotechnology
This is when drugs are put inside very small particles that wouldn’t be able to enter the microbe without the particle
What do bacteriophages have to do with drug resistance?
With some drug-resistant bacteria, bacteriophages can be used to kill those bacteria.
