Question

You are a clinical scientist in a hospital lab who has been given two clinical isolates from a patient. One of the isolates was initially identified as Staphylococcus aureus and the other one as Staphylococcus epidermidis. Which of the following media would you choose to confirm whether the initial identification is correct?

Answer 1

Mannitol Salt Agar (MSA)

Step-by-step explanation:

To confirm the initial identification of the two isolates, you would choose an identification medium that contains a combination of nutrients that are specific to Staphylococcus aureus and Staphylococcus epidermidis. The most common medium used for this purpose is Mannitol Salt Agar (MSA). MSA contains a 7.5% sodium chloride concentration and mannitol, which is a sugar that only Staphylococcus aureus can ferment. The presence of a yellowish-green color indicates the presence of Staphylococcus aureus, while the presence of a colorless halo indicates the presence of Staphylococcus epidermidis.