Lecture 7 Flashcards Preview

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Flashcards in Lecture 7 Deck (105):
1

name a solid culture medium

agar plate

2

name a liquid culture medium

broth

3

name an alive culture medium

host

4

what is a culture medium

what the organism is growing on

5

what is culture?

the mass of organisms

6

do bacteria form colonies in broth?

no, they just make the broth cloudy

7

define inanimate media

media that is not alive

8

Give synonym for non-synthetic media

complex

9

Define non synthetic media

at least one ingredient in the media is not chemically defined

10

what are autotrophs?

grow their own food through photosynthesis and/or chemosynthesis

11

what are heterotrophs?

organisms which need organic media for food

12

what is another word for hypotrophs?

obligate parisites

13

what are hypotrophs?

organisms which need something alive on which to grow

14

Give an synonym for complex media

non-synthetic media

15

what are facilitative heterotrophs?

organisms which can grow on both alive and dead material

16

What is natural media?

you take your media directly from the environment

17

is natural media appropriate for laboratory work?

no

18

is natural media appropriate for commercial work?

yes

19

name 3 examples of natural media

Milk
dead branch
soil

20

What are the disadvantages to natural media?

not chemically defined
not sterile
not suitable for research

21

what are the advantages to natural media?

might be the only media that the organism grows on (such as truffles)

22

Name 2 examples of non synthetic media

natural media
infusional hot water extracts (teas)

23

What does BHI stand for?

brain heart infusions

24

What type of media is BHI?

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