MSA

Question 1

MSA stands for what?

Answer 1

Mannitol Salts Agar

Question 2

What does MSA selectively culture?

Answer 2

Staphylococci bacteria

Question 3

What does MSA differentiate?

Answer 3

Staphylococci aureus

Question 4

What is the selective ingredient?

Answer 4

High salt concentration

Question 5

What are the different ingredients?

Answer 5

Mannitol and penal red

Question 6

Explain how mannitol and phenol red react to create a differentiating property

Answer 6

Mannitol is only fermented by S. aureus. When it’s fermented it is broken down and releases acidic by-products in the process, these acids react with phenol red. When acids are released phenol red changes from a red to yellow color.