Lecture 7 Flashcards
1
Q
name a solid culture medium
A
agar plate
2
Q
name a liquid culture medium
A
broth
3
Q
name an alive culture medium
A
host
4
Q
what is a culture medium
A
what the organism is growing on
5
Q
what is culture?
A
the mass of organisms
6
Q
do bacteria form colonies in broth?
A
no, they just make the broth cloudy
7
Q
define inanimate media
A
media that is not alive
8
Q
Give synonym for non-synthetic media
A
complex
9
Q
Define non synthetic media
A
at least one ingredient in the media is not chemically defined
10
Q
what are autotrophs?
A
grow their own food through photosynthesis and/or chemosynthesis
11
Q
what are heterotrophs?
A
organisms which need organic media for food
12
Q
what is another word for hypotrophs?
A
obligate parisites
13
Q
what are hypotrophs?
A
organisms which need something alive on which to grow
14
Q
Give an synonym for complex media
A
non-synthetic media
15
Q
what are facilitative heterotrophs?
A
organisms which can grow on both alive and dead material
16
Q
What is natural media?
A
you take your media directly from the environment
17
Q
is natural media appropriate for laboratory work?
A
no
18
Q
is natural media appropriate for commercial work?
A
yes
19
Q
name 3 examples of natural media
A
Milk
dead branch
soil
20
Q
What are the disadvantages to natural media?
A
not chemically defined
not sterile
not suitable for research
21
Q
what are the advantages to natural media?
A
might be the only media that the organism grows on (such as truffles)
22
Q
Name 2 examples of non synthetic media
A
natural media
infusional hot water extracts (teas)
23
Q
What does BHI stand for?
A
brain heart infusions
24
Q
What type of media is BHI?
A
infusional hot water extract (tea)
non synthetic
inanimate
25
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
26
Is BHI sterile?
yes once autoclaved
27
is BHI suitable for scientific studies?
yes
28
What bacteria can be grown on BHI?
Streptococci pneumoniae
29
What are the advantages to BHI?
sterile
can be used for clinical isolates
can be used in antibiotics research
30
What are the disadvantages of BHI?
some organisms won't grow on it becuase you cooked it
| is not chemically defined
31
What do you use teas for?
to isolate clinical pathogens in clinical labs
32
Define synthetic media
all chemical components are completely defined and quantified
33
What can you add to media as an organic source of nitrogen?
amino acids
34
What can you add to media as an inorganic source of nitrogen?
ammonium or potassium nitrate
35
What organism needs nitrogen?
staphylococcus aureus
36
What kind of organism needs inorganic nitrogen?
autotrophs
37
What are the advantages to synthetic media?
chemically defined
sterile
pure culture can be grown
38
What are the disadvantages of synthetic media?
not suitable in clinical setting
expensive
not all organisms will grow on it
39
What is the goal of isolation medium?
to isolate an organism from its natural environment and grow it on a medium
40
What can you use as an isolation medium for a human pathogen?
BHI and sheep's blood
41
What is the goal of using differentiation media?
looking for a specific reaction or a way to tell that a specific organism is present
42
Name examples of differentiation media
blood agar plate
mannitol salt agar
macconkey's agar
eosin methylene blue agar
43
which differentiation media is used to find staphylococcus aureus?
blood agar
| mannitol salt
44
Which differentiation media is used to find streptococcus pneumoniae?
blood agar
45
Which differentiation media is used to find choliforms?
macconkey's agar
| eosin methylene blue agar
46
What are the three possible reactions to blood agar called?
gamma reaction
beta hemolysis
alpha hemolysis
47
What is a gamma reaction?
when there is no change in color of the blood agar media around the colony
no hemolysis
no reaction
nonpathogenic
48
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)
pathogenic
49
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
50
What organism shows beta hemolysis?
staphylococcus aureus
51
What organism shows alpha hemolysis?
streptococcus pneumoniae
52
What organism is used for mannitol salt agar?
staphylococcus aureus
53
What is mannitol?
a sugar alcohol that staph. aureus can digest
54
What happens when Staph. aureus digests mannitol?
produces acid
55
What color does the mannitol salt agar turn for a positive result?
yellow
56
What color does mannitol salt agar turn for a negative result?
red
57
What is the reactive ingredient in MacConkey's agar?
lactose
58
What does MacConkey's agar do?
isolates choliforms
59
What are choliforms?
bacteria in your poop and GI tract
60
What does a positive result on MacConkey's agar look like?
the colony will turn pink
61
What does Eosin methylene blue agar test for?
choliforms
62
What does a positive result in eosin methylene blue agar look like?
purple colonies
63
Name three selective media
Mannitol salt agar
MacConkeys agar
eosin methylene blue agar
64
What is selective media?
Favors the growth of a specific organism while inhibiting the growth of others
65
What makes mannitol salt agar selective?
high salt concentration
66
What does mannitol salt agar favor and what does it inhibit?
favors staphylococcus aureus
| inhibits streptococci
67
What makes macconkey's agar selective?
bile which emulsifies lipids
68
What does macconkey's favor and why?
G- bacteria because of their lipo-poly-saccharride outer membrane
69
What makes eosin methylene blue selective?
dyes
70
What does EMB favor and what does it inhibit?
favors G-
| inhibits G+
71
What is enriched media?
extra ingredients are added to promote the growth of certain organisms
72
Name some enriched media
BHI with sheeps blood
Louenstein jensen
Chocolate agar
73
Enriched BHI is to promote the growth of what?
streptococcus pneumoniae
74
louenstein jensen is an enriched media to grow what?
Mycobacterium
75
Chocolate agar is an enriched medium to grow what?
haemophillus influenzae
| neisseria gonorrhea
76
Is BHI with sheeps blood selective? why?
no, it doesn't inhibt the growth of an organism
77
Is BHI with sheeps blood an isolation medium? why?
yes, because it isolates strep pneumo from it's natural environment
78
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
79
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
80
Is louenstein jensen an isolation medium?
yes
81
Is louenstein jensen a differential medium?
no
82
Is louenstein jensen an enriched medium? why?
yes, TB won't grow on BHI alone and it needs the lounestein jensen to grow
83
Is louenstein jensen a selective medium? why?
yes, it inhibits G+ firmicutes and favors actinobacteria
84
Is chocolate agar an isolation medium?
no
85
Is chocolate agar a differential medium?
no
86
Is chocolate agar an enriched medium?
yes
87
Is chocolate agar a selective medium?
no
88
How do you make chocolate agar?
heat up blood agar plate to 100 degrees and the hemoglobin will break down turning the blood brown
89
What should you use thayer martin selective agar to grow?
neisseria
90
What is VCA?
vancomycin
colistin
nystatin
91
what does vancomycin do?
inhibits G+ bacteria
92
What does colistin do?
inhibits G- rods
93
What does Nystatin do?
inhibits yeast
94
What should you use VCA to grow?
neisseria
95
Name a liquid medium
BHI broth
96
How do you make BHI broth?
BHI powder and water
97
What temperature does BHI agar melt at?
100 degrees
98
What temperature do you autoclave at?
121.5 degrees
99
What temperature is molten agar?
45 to 50 degrees
100
At what temperature does BHI agar solidify?
40 degrees
101
What is BHI agar?
BHI and 1.5% agar
102
What is the difference between a solid medium and a liquifyable solid medium?
you cannot remelt a solid medium
103
Name some solid mediums
blood agar plate
| Silica
104
At what temperature does a blood agar plate become a chocolate agar plate?
100 degrees
105
What is hemolysis?
the breaking open of red blood cells and the release of hemoglobin into the surrounding fluid
