LESOON 12: CULTURE MEDIA Flashcards

1
Q

Usually confirmed by isolating and
culturing microorganisms in artificial media.

A

Laboratory diagnosis of an infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bacteria and fungi are cultured in either
liquid (broth) or on solid (agar) artificial media.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pioneered the use of
agar as a base for culture media as suggested by Fannie Eilshemius Hesse, the wife
of Walther Hesse, one of Koch’s a assistance

A

Robert koch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Developed the Petri dish (plate), a container for solid culture.

A

Richard Petri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

developed the pour plate method and was the first to use solid culture media
for culture of bacteria.

A

Robert Koch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A nutrient material prepared for the growth of microorganisms in a
laboratory is called a

A

culture medium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When microbes are introduced into a culture medium to initiate growth,
they are called an

A

Inoculum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The microbes that grow and multiply in or on a culture medium are referred
to as

A

Culture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

: is the process of growing microorganisms in culture by taking bacteria
from the infection site (i.e. in vivo environment)
bacteria culture within the living

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

some means of specimen
collection and growing them in the artificial environment of the laboratory (i.e. the in
vitro environment)
bacteria culture growth outside laboratory

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

a laboratory culture containing a single species of organism.

A

Pure culture: a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Bacterial cultivation has three main purposes :

A

i. To grow and isolate all bacteria present in an infection.

ii. Infection and contaminants or colonizers:
To determine which of the bacteria that
grow are most likely causing infection and which are likely contaminants or
colonizers.

iii. Identification and characterization:
To obtain sufficient growth of clinically relevant
bacteria to allow identification and

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ingredients of Culture Media
Some of the components of culture media are as follows:

A
  1. water
  2. agar
  3. peptone
  4. Yeast Extract
  5. malt Extract
  6. Blood And Serum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

often suitable for culture media, particularly if it has a low
mineral content, however glass-distilled or demineralized water

A

Tap water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Prepared from a variety of seaweeds and is now universally used for preparing solid media.
Agar does not add to the nutritive
properties of a medium and is not affected by the growth of bacteria.

A

Agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

the nutritive properties of a medium and is not affected by the growth of bacteria. The melting and solidifying points of agar solutions.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

At the concentrations
normally used,
most bacteriological agars melt at about 95°C and solidify only when
cooled to about 42°C.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Another almost universal ingredient of common media

A

peptone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

It is a complex mixture of partially digested proteins.

A

Peptone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The important constituents are
peptones, proteoses , amino acids, a variety of inorganic salts including phosphates, potassium and magnesium, and certain accessory growth factors such as nicotinic
acid and riboflavin.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Commercially available peptones or digest broth can be used.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Is also available commercially and is known as LabLemco.

A

Meat Extract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

It contains a wide range of amino acids, growth factors and
inorganic salts.

A

Yeast Extract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Used mainly as a comprehensive source of growth factors and may be substituted for meat extract in culture media.

A

Yeast Factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

It consists mainly of maltose (about 50%), starch, dextrins and
glucose, and contains about 5 percent of proteins and protein breakdown products, and a wide range of mineral salts.

A

Malt extract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

These are used for enriching culture media

A

blood and serum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Usually 5-10 percent blood is used and the most usual
concentration is 10 percent.

Serum is used in certain media

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

CLASSIIFICATION OF MEDIA :

A

A. PHASES OF GROWTH MEDIQ
B. BASED ON NUTIRIONAL FACTORS
C. DEFINED MEDIA
D. SPECIAL MEDIA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

A. PHASES OF GROWTH MEDIA

A
  1. LIQUID (BROTH) MEDIA
  2. SOLID (AGAR) MEDIA
  3. SEMISOLID MEDIA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The earliest culture media were liquid. The original media used by Louis Pasteur were liquids such as urine or meat broth.

A

LIQUID MEDIA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In broth media nutrients are dissolved in water, and bacterial growth is indicated by a change
in broth’s appearance from clear to turbid, (i.e. cloudy).

A
33
Q

Uses
(I) for obtaining
bacterial growth from blood or water when large volumes have to be tested
(ii) for preparing bulk cultures of antigens or vaccines.

A
34
Q

Are made by adding a solidifying agent to
the nutrients and water.

A

SOLID (AGAR) MEDIA

35
Q

Is the most common solidifying agent.

A

AGAROSE

36
Q

The Petri dish containing the agar is referred to as

A

AGAR

37
Q

provide isolated colonies that can be quantified and identified.
Some genera and species can be recognized on the basis of their colony
morphologies.

A
38
Q

Clones of cells originating from a single bacterial cell.

A

COLONIES

39
Q

Derived from a single colony or clone are considered “pure”.

A

BACTERIAL CULTURES

40
Q

Prepared by adding 2% agar to nutrient broth is the simplest and most
common medium used routinely in diagnostic laboratories.

A

NUTRIENT AGAR

41
Q

Other examples of solid
media include blood agar, chocolate agar, MacConkey agar, etc

A
42
Q

For special purposes where agar is added to media in concentrations that are too low to solidify them.

A

SEMISOLID

43
Q

At 0.2 to 0.5 percent it yields a
semisolid medium through which motile, but not non motile, bacteria may spread.

A
44
Q

The simple or basal media include nutrient broth and peptone water, which form the basis.

A

Simple (basal) media:

45
Q

Is an example of a simple liquid medium that consists of peptone, meat extract, sodium chloride, and water. Addition of 0.5% glucose to nutrient broth makes it glucose broth.

A

■ Nutrient broth

46
Q

An example of a simple solid medium. The medium is
used routinely for isolation of many bacteria from clinical specimen

A

Nutrient agar

47
Q

Media that contain some ingredients of unknown chemical composition.
A complex medium contains a variety of ingredients such as meat juices and digested proteins.

A

Complex media:

48
Q

The complex media contain

A

(1) Water,
(2) Acarbon source such as glucose for bacterial growth,
(3) Various salts needed for
bacterial growth, and
(4) A source of amino acids and nitrogen (e.g., beef and yeast
extract).

49
Q

Is a synthetic kind of medium which contains known quantities of all
ingredients used but does not contain any animal, yeast, or plant tissue.

A

C. Defined Media

50
Q

These media consist of
(1) Trace elements and vitamins;
(2) A defined carbon source and
nitrogen source required by certain microbes.

Examples are glucose or glycerol and ammonium salts or nitrates respectively such as Dubos’ medium with Tween 80

A
51
Q

D. 6 Special Media

A
  1. Enriched media
    2 . Enrichment media
  2. Selective media
  3. Differential or indicator media
  4. Transport media
  5. Sugar media
52
Q

Invariably solid media that
facilitate growth of certain fastidious bacteria.

A

Enriched media

53
Q

These media are prepared by adding
substances like blood, serum, and egg to the basal media in order to meet the
nutritional requirements of more exacting and more fastidious bacteria. B

A
54
Q

Example of enriched media.

A

Blood agar,
chocolate agar
Loeffler’s serum slope
LJ medium

55
Q

an enriched medium in which nutritionally rich whole blood supplements constitute the basic nutrients.

A

Blood agar

56
Q

is enriched with heat-treated blood (80°C), which turns brown and gives the medium the color for which it is named.

A

Chocolate agar

57
Q

Are liquid media that stimulate the
growth of certain bacteria or suppress the growth of others for isolation of desired
pathogenic bacteria.

A

Enrichment media:

58
Q

In such situations, enrichment
media (such as selenite-F broth or tetrathionate broth) are used for the isolation of Salmonella typhi and Shigella spp.

A
59
Q

Solid media that contain substances that inhibit
the growth of all but a few bacteria but at the same time facilitate isolation of certain
bacteria.

A

Selective media

60
Q

Examples of selective media include:

A

(a) Thiosulfate citrate bile salt
sucrose agar (TCBS) selective for the isolation of Vibrio cholerae,
(b) Deoxycholate
citrate agar (DCA) selective for enteric bacilli, such as Salmonella spp. and Shigella
spp.,
(c) LJ medium selective for Mycobacterium tuberculosis,
(d) Hektoen enteric
(HE) agar selective for Gram-negative bacteria,
(e) Mannitol salt agar (MSA)
selective for Gram-positive bacteria,
(f) Xylose lysine desoxycholate (XLD) agar
selective for Gram-negative bacteria,
(g) Buffered charcoal yeast extract agar
selective for certain Gram-negative bacteria, such as Legionella pneumophila.

61
Q

Examples:
(a) Eosin methylene blue (EMB), differential for lactose
and sucrose fermentation;
(b) MacConkey, differential for lactose fermentation;
(c) Mannitol salt agar (MSA), differential for mannitol fermentation; and
(d) X-gal plates, differential for lac operon mutants for detection of recombinant strains of bacteria for
study in molecular microbiology

A
61
Q

Distinguish one microorganism from another growing on the same media by their growth characteristics.

A

Differential or indicator media

61
Q

They typically contain only buffers and salt. They lack carbon, nitrogen, and organic growth factors, hence do not facilitate microbial multiplication.

A

Trasnport media

61
Q

used to maintain the viability of
certain delicate organisms in clinical specimens during their transport to the
laboratory.

A

Transport media

61
Q

Examples :
are Stuart’s transport medium for Neisseria gonorrhoeae.

A
62
Q

Basically contains 1% “sugar”, which in
microbiology denotes any fermentable substance, such as glucose, sucrose, lactose, and mannitol that is routinely used

A

Sugar media

63
Q

Preserving Bacterial Culture

A
64
Q

Can be used for the short-term storage of bacterial
cultures.

A

Refrigeration

65
Q

A process in which a pure culture of microbes is placed in a suspending liquid and quick-frozen at temperatures ranging from - 50º to -95°C.
The culture can usually be thawed and cultured even several years later.

A

Deep freezing

66
Q

A suspension of microbes is quickly frozen at temperatures ranging from -54º to -95ºC, and the water is removed by a high vacuum (sublimation).
The organisms can be revived at any time by hydration with a suitable liquid nutrient

A

Lyophilization (Freeze dying)

67
Q

A common method of preserving strains of bacteria.

A

Cold Storage

68
Q
A
68
Q
A
68
Q

A number of for drying suspensions of bacteria for preservation purposes have been developed.

A

Drying methods

69
Q
A
69
Q
A
70
Q
A
70
Q
A
70
Q
A