What is the most appropriate screening media for Staphylococcus aureus in the nursery department?

Mannitol salt agar is the most appropriate screening media for Staphylococcus aureus in a nursery department due to its selective and differential properties. This medium contains a high concentration of sodium chloride, which inhibits the growth of most other bacteria, allowing for the isolation of salt-tolerant organisms like Staphylococcus.

Furthermore, mannitol salt agar contains mannitol, a sugar alcohol that Staphylococcus aureus can ferment, producing acid and leading to a color change in the medium. This distinctive color change—from red to yellow—indicates the presence of Staphylococcus aureus, making it not only selective but also useful for differentiating it from other Staphylococcus species that do not ferment mannitol.

This characteristic is particularly relevant in a nursery setting, where Staphylococcus aureus could be a concern for infections, and the ability to rapidly identify and confirm its presence is essential for effective infection control measures. Other media listed may support the growth of various bacteria, but they do not provide the same level of specificity for Staphylococcus aureus as mannitol salt agar does.