9. Culture Media

8/3/2019 9. Culture Media

1/23

Culture Media


2/23

Culture Media

is a solid or gel based

substance facilitating thegrowth of

micro organisms or tissues.


3/23

Culture media can be usedin three forms

1.Solid2.Semisolid

3.Fluid


4/23

Basic type of Culture

media

Bacterial Culture media.

Viral Culture media.

Tissue Culture media.


5/23

Common ingredients of

Culture media

Peptone

Meat extracts

Yeast extracts Mineral salts


6/23

Carbohydrates

Agar Water


7/23

Main types of culture

media Basic

Enriched and enrichment Selective

Differential

Transport


8/23

Basic media

a simple media such as

nutrient agar or broth

do not have specialnutritional requirements


9/23

Is often used

1.in preparation of enrichedmedia

2.maintain stock culture ofcontrol strains of bacteria

3.For subculturingpathogens fromdifferential or selective

media


10/23

Enriched media

provide additional nutrientsor growth stimulants

are required for culture of

1. H. influenzae

2. Pathogenic Neisseria

3. Several Streptococcusspecies


11/23

are enriched with

whole blood

lyzed blood

serum

Extra peptones

Special extracts orvitamin


12/23

Examples

1.Blood agar

2.Chocolate agar etc


13/23

Enrichment media

Fluid medium that increasesthe numbers of a pathogen by

containing enrichments, andor substances that

discourage the multiplicationof unwanted bacteria.


14/23

Example:

Selenite F broth is used anenrichment media for

Salmonellae in faeces orurine prior to subculturing

on xylose lysinedeoxycholate agar or other

enteric selective medium.


15/23

Selective media

Facilitate the growth of

some pathogenicorganisms

Prevent or slow down the

growth of other organisms


16/23

Examples

1. SS agar Facilitate growth of

salmonella and shigella Inhibite growth of

many faecalcommensals (bycontaining Bile salt)


17/23

2.Modified New York City

(MNYC) medium Used to isolate

N. gonorrhoeaefromurethral specimens


18/23

3. Butzler medium to isolate

Compylobacter sppfromfaeces

Available for isolating most

of important organisms


19/23

Differential (indicator)

mediacontain some indicators,

dyes, other substanceshelp to differentiate

microorganisms


20/23

Examples

1.TCBS agar Indicator bromothymol

blue Differentiate sucrose

fermenting from nonfermenting Vibrio spp


21/23


22/23

Transport media

Mostly a semisolid media

Prevent the overgrowth ofcimmensals

Ensure the survival of

aerobic and anaerobicpathogens


23/23

Used to transport the

microbial specimens Examples

1.Amies transport medium

2.Cary-Blair medium

Documents

9. Culture Media