Flashcards in Lecture 7 Deck (105):
name a solid culture medium
name a liquid culture medium
name an alive culture medium
what is a culture medium
what the organism is growing on
what is culture?
the mass of organisms
do bacteria form colonies in broth?
no, they just make the broth cloudy
define inanimate media
media that is not alive
Give synonym for non-synthetic media
Define non synthetic media
at least one ingredient in the media is not chemically defined
what are autotrophs?
grow their own food through photosynthesis and/or chemosynthesis
what are heterotrophs?
organisms which need organic media for food
what is another word for hypotrophs?
what are hypotrophs?
organisms which need something alive on which to grow
Give an synonym for complex media
what are facilitative heterotrophs?
organisms which can grow on both alive and dead material
What is natural media?
you take your media directly from the environment
is natural media appropriate for laboratory work?
is natural media appropriate for commercial work?
name 3 examples of natural media
What are the disadvantages to natural media?
not chemically defined
not suitable for research
what are the advantages to natural media?
might be the only media that the organism grows on (such as truffles)
Name 2 examples of non synthetic media
infusional hot water extracts (teas)
What does BHI stand for?
brain heart infusions
What type of media is BHI?
infusional hot water extract (tea)
how do you make BHI?
boil cow brains and hearts until everything is soluble, then evaporate the liquid, powder the solid that is left behind after evaporation
Is BHI sterile?
yes once autoclaved
is BHI suitable for scientific studies?
What bacteria can be grown on BHI?
What are the advantages to BHI?
can be used for clinical isolates
can be used in antibiotics research
What are the disadvantages of BHI?
some organisms won't grow on it becuase you cooked it
is not chemically defined
What do you use teas for?
to isolate clinical pathogens in clinical labs
Define synthetic media
all chemical components are completely defined and quantified
What can you add to media as an organic source of nitrogen?
What can you add to media as an inorganic source of nitrogen?
ammonium or potassium nitrate
What organism needs nitrogen?
What kind of organism needs inorganic nitrogen?
What are the advantages to synthetic media?
pure culture can be grown
What are the disadvantages of synthetic media?
not suitable in clinical setting
not all organisms will grow on it
What is the goal of isolation medium?
to isolate an organism from its natural environment and grow it on a medium
What can you use as an isolation medium for a human pathogen?
BHI and sheep's blood
What is the goal of using differentiation media?
looking for a specific reaction or a way to tell that a specific organism is present
Name examples of differentiation media
blood agar plate
mannitol salt agar
eosin methylene blue agar
which differentiation media is used to find staphylococcus aureus?
Which differentiation media is used to find streptococcus pneumoniae?
Which differentiation media is used to find choliforms?
eosin methylene blue agar
What are the three possible reactions to blood agar called?
What is a gamma reaction?
when there is no change in color of the blood agar media around the colony
What is beta hemolysis?
complete breakdown of the blood in the blood agar medium as shown by a clear area around each colony (where the blood was broken down)
What is alpha hemolysis?
Partial breakdown of the blood in the blood agar medium as shown by a greenish color around the colony
may or may not be pathogenic
What organism shows beta hemolysis?
What organism shows alpha hemolysis?
What organism is used for mannitol salt agar?
What is mannitol?
a sugar alcohol that staph. aureus can digest
What happens when Staph. aureus digests mannitol?
What color does the mannitol salt agar turn for a positive result?
What color does mannitol salt agar turn for a negative result?
What is the reactive ingredient in MacConkey's agar?
What does MacConkey's agar do?
What are choliforms?
bacteria in your poop and GI tract
What does a positive result on MacConkey's agar look like?
the colony will turn pink
What does Eosin methylene blue agar test for?
What does a positive result in eosin methylene blue agar look like?
Name three selective media
Mannitol salt agar
eosin methylene blue agar
What is selective media?
Favors the growth of a specific organism while inhibiting the growth of others
What makes mannitol salt agar selective?
high salt concentration
What does mannitol salt agar favor and what does it inhibit?
favors staphylococcus aureus
What makes macconkey's agar selective?
bile which emulsifies lipids
What does macconkey's favor and why?
G- bacteria because of their lipo-poly-saccharride outer membrane
What makes eosin methylene blue selective?
What does EMB favor and what does it inhibit?
What is enriched media?
extra ingredients are added to promote the growth of certain organisms
Name some enriched media
BHI with sheeps blood
Enriched BHI is to promote the growth of what?
louenstein jensen is an enriched media to grow what?
Chocolate agar is an enriched medium to grow what?
Is BHI with sheeps blood selective? why?
no, it doesn't inhibt the growth of an organism
Is BHI with sheeps blood an isolation medium? why?
yes, because it isolates strep pneumo from it's natural environment
Is BHI with sheeps blood differential? why?
yes because depending on how an organism reacts with the blood you can tell what kind of organism you have
Is BHI with sheeps blood enriched? why?
yes it is, it is BHI which has been enriched by sheeps blood to better grow strep pneumo
Is louenstein jensen an isolation medium?
Is louenstein jensen a differential medium?
Is louenstein jensen an enriched medium? why?
yes, TB won't grow on BHI alone and it needs the lounestein jensen to grow
Is louenstein jensen a selective medium? why?
yes, it inhibits G+ firmicutes and favors actinobacteria
Is chocolate agar an isolation medium?
Is chocolate agar a differential medium?
Is chocolate agar an enriched medium?
Is chocolate agar a selective medium?
How do you make chocolate agar?
heat up blood agar plate to 100 degrees and the hemoglobin will break down turning the blood brown
What should you use thayer martin selective agar to grow?
What is VCA?
what does vancomycin do?
inhibits G+ bacteria
What does colistin do?
inhibits G- rods
What does Nystatin do?
What should you use VCA to grow?
Name a liquid medium
How do you make BHI broth?
BHI powder and water
What temperature does BHI agar melt at?
What temperature do you autoclave at?
What temperature is molten agar?
45 to 50 degrees
At what temperature does BHI agar solidify?
What is BHI agar?
BHI and 1.5% agar
What is the difference between a solid medium and a liquifyable solid medium?
you cannot remelt a solid medium
Name some solid mediums
blood agar plate
At what temperature does a blood agar plate become a chocolate agar plate?