How do you make agar MSA?
- Suspend 111 grams of Mannitol Salt Agar in 1000 ml of distilled water.
- Boil to dissolve the medium completely.
- Sterilize by autoclaving at 15 lbs.
- If desired, sterile Egg Yolk Emulsion (E7899) can be added to a final concentration of 5% v/v after autoclaving.
Similarly, it is asked, what does MSA agar test for?
Mannitol Salt Agar (MSA) is used as a selective and differential medium for the isolation and identification of Staphylococcus aureus from clinical and non-clinical specimens. It encourages the growth of a group of certain bacteria while inhibiting the growth of others.
Likewise, what Bacteria grows on MSA? Most pathogenic staphylococci, such as Staphylococcus aureus, will ferment mannitol. Most non-pathogenic staphylococci will not ferment mannitol. The Staphylococcus aureus ferments mannitol and turns the medium yellow. The Serratia marcescens does not grow because of the high salt content.
Similarly, it is asked, which organisms did not grow on MSA plate?
Expected colony characteristics of organism in Mannitol Salt Agar
- Escherichia coli: Does not grow.
- Staphylococcus epidermidis: Colorless to pink colonies.
- Staphylococcus aureus: Yellow colonies; may have yellow halo around colonies.
What chemical ingredient makes MSA selective?
Mannitol salt agar is selective due to the presence of 7.5% sodium chloride (NaCl).