LEC 5_Culture Media

Culture Media according to Use

Simple/ General Purpose / Supportive Media

Are routinely used in the laboratory and without added supplement

Simple/ General Purpose / Supportive Media

Are media that support the growth of most non-fastidious bacteria

Simple/ General Purpose / Supportive Media

These are made up of meat and soybean extracts

Enrichment Broth (Liquid-type Media)

It is used to propagate the growth of certain groups of organisms

Enrichment Broth (Liquid-type Media)

They contain specific nutrients

Enrichment Broth (Liquid-type Media)

It can also be used as supplement to agar plates to detect aerobes, anaerobes, and microaerophiles

Enrichment Broth (Liquid-type Media)

These media are incubated for a certain period and then subcultured to isolate the desired microorganisms

Enriched and Non-selective Media

These are media with added supplements such as blood (Type O), vitamins, and yeast extract, necessary for the growth of fastidious organisms

Non-selective Media

it allows the growth of all organisms including fastidious organisms (no inhibitory agents)

Blood Agar Plate (BAP)

the standard nonselective culture medium

Chocolate Agar Plate (CAP)

Agar Plate with horse blood is used for the isolation of Haemophilus wherein blood is lysed by heating

Hemin and nicotinamide adenine dinucleotide

growth requirement for Neisseria spp and Haemophilus spp

Differential Media

These media allow the visualization of metabolic differences between groups of bacteria

Differential Media

Media in which change in the phenotypic characteristics of the media

MacConkey Agar
lactose fermenters (pink colonies)
non-lactose fermenters (colorless colonies)

differentiates lactose fermenters from non-lactose fermenters; color indications

Blood Agar Plate (BAP)

differentiates hemolytic pattern of Streptococci

Eosin Methylene Blue (EMB)
E. coli (greenish metallic sheen)
other lactose fermenting bacteria (dark purple colonies)

differentiates (E. coli) greenish metallic sheen colonies from other lactose fermenting bacteria (dark purple colonies); color indications

Salmonella (bluish green with black centers)
Shigella (green)
Other coliforms (orange or salmon pink)

identifies the Salmonella and Shigella (bluish green colonies with black centers) from Shigella (green colonies) while the other coliforms appear orange or salmon pink colonies

CLED (Cystine Lactose Electrolyte Deficient) agar
Lactose-fermenting bacteria (yellow)
Lactose-non-fermenting bacteria (colorless/pale)

characterizes those bacteria that utilize lactose (both yellow colonies and medium), and it is recommended for urine culture

Selective Media

These are media incorporated with antibiotics, dyes, or chemicals to inhibit the growth of other organisms while promoting the growth of the desired organism

Selective Media

Has inhibitory substances that prevent the growth of other organisms and promote the growth of target organisms

Special Media

used to isolate bacteria with specific growth requirements

Löwenstein–Jensen medium; cauliflower-like colonies

has egg and malachite green that facilitates the growth of Mycobacterium tuberculosis; colony shape