What is the purpose of potassium tellurite in tellurite medium?

Potassium tellurite serves a specific function in tellurite medium, primarily as an inhibitor of normal flora. By inhibiting the growth of many non-pathogenic bacteria, potassium tellurite allows for the selective growth of certain pathogens, particularly Staphylococcus aureus. This selective inhibition is crucial because it helps to isolate and identify the pathogens present in a sample without interference from the surrounding normal flora, which could otherwise complicate the diagnostic process.

The capacity of potassium tellurite to create a specific environment where only certain microorganisms can thrive is essential in microbiological studies, particularly in identifying pathogens that are of clinical significance. Thus, its role as an inhibitory agent is key to the intended use of the medium.