Difference Between Blood Agar and MacConkey Agar

The key difference between blood agar and MacConkey agar is that blood agar is an enriched differential medium used to isolate fastidious microorganisms and detect their hemolytic activity whereas MacConkey agar is a selective and differential medium used to differentiate between non-fastidious gram-negative bacteria ...

1. What is the major difference between blood agar and chocolate agar?
2. What is the use of MacConkey Agar?
3. What Bacteria grows on MacConkey Agar?
4. What does blood agar differentiate between?
5. What type of media is blood agar?
6. What type of bacteria grow on blood agar?
7. How do you interpret MacConkey Agar?
8. Is MacConkey Agar defined?
9. Why is MacConkey agar used for E coli?
10. What color is E coli on MacConkey Agar?
11. Will E coli grow on MacConkey Agar?
12. Can Streptococcus grow on MacConkey Agar?

What is the major difference between blood agar and chocolate agar?

Chocolate agar is used for the isolation of fastidious organisms, such as Haemophilus influenzae, when incubated at 35-37°C in a 5% CO2 atmosphere. The composition of chocolate agar and the Blood Agar is the same and the only difference is while preparing chocolate agar, the red blood cells are lysed.

What is the use of MacConkey Agar?

MacConkey Agar (MAC) is a selective and differential medium designed to isolate and differentiate enterics based on their ability to ferment lactose. Bile salts and crystal violet inhibit the growth of Gram positive organisms.

What Bacteria grows on MacConkey Agar?

Altogether, MacConkey agar only grows gram-negative bacteria, and those bacteria will appear differently based on their lactose fermenting ability as well as the rate of fermentation and the presence of a capsule or not.

What does blood agar differentiate between?

Blood agar is a general purpose enriched medium often used to grow fastidious organisms and to differentiate bacteria based on their hemolytic properties.

What type of media is blood agar?

Blood agar is an enriched, bacterial growth medium. Fastidious organisms, such as streptococci, do not grow well on ordinary growth media. Blood agar is a type of growth medium (trypticase soy agar enriched with 5% sheep blood) that encourages the growth of bacteria, such as streptococci, that otherwise wouldn't grow.

What type of bacteria grow on blood agar?

Blood Agar is used to grow a wide range of pathogens particularly those that are more difficult to grow such as Haemophilus influenzae, Streptococcus pneumoniae and Neisseria species. It is also required to detect and differentiate haemolytic bacteria, especially Streptococcus species.

How do you interpret MacConkey Agar?

Result Interpretation on MacConkey Agar

Lactose fermenting strains grow as red or pink and may be surrounded by a zone of acid precipitated bile. The red colour is due to production of acid from lactose, absorption of neutral red and a subsequent colour change of the dye when the pH of medium falls below 6.8.

Is MacConkey Agar defined?

MacConkey Agar is a selective medium, Is it also a defined or an undefined medium? Why is that formulation desirable? Undefined, it's beneficial because it gives a wide variety of growth ability. ... Only gram-negatives will grow on MacConkey, so you always want to streak to something that you know it will grow on.

Why is MacConkey agar used for E coli?

Sorbitol MacConkey agar is a variant of traditional MacConkey agar used in the detection of E. coli O157:H7. ... This is important because gut bacteria, such as Escherichia coli, can typically ferment lactose, while important gut pathogens, such as Salmonella enterica and most shigellas are unable to ferment lactose.

What color is E coli on MacConkey Agar?

coli was made based on its characteristic morphology colony on the selective medium MacConkey agar. Rapid lactose fermenting colonies of E. coli appear dry, donut shaped and dark pink in color and are surrounded with dark pink area of precipitated bile salts.

Will E coli grow on MacConkey Agar?

Selective and Differential Media

MacConkey agar not only selects for Gram-negative organisms by inhibiting Gram-positive organisms and yeast but also differentiates the Gram-negative organisms by lactose fermentation. ... Escherichia coli and other lactose ferments will produce yellow or orange colonies.

Can Streptococcus grow on MacConkey Agar?

Streptococcus pneumoniae (S. ... Hence, it does not grow on MacConkey agar (MA) due to the absence of blood as well as due to the presence of high concentration of bile in the medium which is inhibitory to the growth of S. pneumoniae.