CH6 Primary Inoculation (MEDIA)

What are the 7 Standard Medium Types?

1. Nonselective

2. Selective

3. Differential

4. Differential + Selective

5. Enriched

6. Enrichment BROTH

7. Broth MEDIA

What does Nonselective Media support growth for?

Most NON-FASTIDIOUS organisms:

Staph and Strep

non-fastidious = no es fastidioso, does not need much to grow.

What are 2 types of Nonselective Media?

1. Sheep Blood Agar

2. TSA +5% SHEEP BLOOD

What does Selective Media support the growth of?

ONE TYPE of organism and NOT another one

Such as growing only gram positive and killing gram negative VICE VERSA

What is one type of Selective Media?

Columbia Nalidixic Acid (CNA) agar

Columbia is SELECTIVE for which students get in

What kind of bacteria does CNA agar favor?

Gram POSITIVE

Staphylococcus

streptococcus

enterococcus

What does Differential Media support the growth of?

It allows for organisms to be distinguished by their VISIBLE GROWTH CHARACTERISTICS

such as different hemolysis

What is an example of a Differential Media?

Sheep Blood Agar - shows the different hemolysis

TSA +5% Sheep Blood

What does Enriched media support the growth of?

SAME AS NONSELECTIVE but with ADDED growth factors

What is an example of an Enriched media?

Chocolate agar:

FASTIDOUS organisms

Fastidiosos want chocolate

Haemophilus influenza and Neisseria spp.

What does Enrichment Broth support the growth of?

Enhances SPECIFIC ORGANISM while REDUCING competing flora

What is an example of an Enrichment Broth and what does it enhance the recovery of?

Lim Broth enhances recover of GROUP B Streptococcus

Which BROTH is used for Group B streptococcus enrichment?

Lim Broth

What do the Selective + Differential mediums do?

SELECT one group and DIFFERENTIATES members within the group

Which is the main example of a Selective + Differential Media?

MacConkey Agar - differentiate based on LACTOSE FERMANTATION

Which medium SELECTS Gram-Negative organisms and DIFFERENTIATES lactose fermentation?

MacConkey Agar

What is the main purpose of Broth Medium?

Help recover SMALL NUMBERS and also supports VARYING OXYGEN needs

What is an example of a Broth Medium?

Thioglycolate broth - aerobes, anaerobes, facultative organisms

Why might a LARGE-VOLUME sterile body fluid be CENTRIFUGED before culture?

To concentrate organisms that may be present in low numbers

What are the 2 methods of isolation?

1. Isolation 4 quadrant streak

2. Quantitative Isolation - Streak DOWN CENTER

For which specimen are Quantitative Isolations MOST USED FOR ?

Urine Cultures

What is the purpose of Isolation streaks (4 quadrant)?

To create ISOLATED COLONIES

The 4 quadrant is to dilute (most colonies on the final streak)

What are Quantitative Isolations mostly used for?

Urine and it is to COUNT COLONIES (concentration)

What to Capnophilic organisms prefer?

CO2

What do Microaerophilic organisms prefer?

DECREASED O2 levels

What do Anaerobic organisms prefer?

NO O2