Staphylococcus Selective Agar Culture Media

Microbiological Grade

Room Temperature

This medium contains lithium chloride and tellurite to inhibit the growth of accompanying microbial flora, whereas pyruvate and glycine selectively stimulate the growth of staphylococci.
Staphylococcus colonies show two characteristic features when grown in this opaque medium (opaque, because of its egg-yolk content)
a) characteristic zones and rings are formed as a result of lipolysis and proteolysis,
b) reduction of tellurite to tellurium produces a black coloration.
The egg-yolk reaction and tellurite reduction are usually found to occur together with a positive coagulase reaction and can thus serve as an index for the latter.
Stadhouders et al. (1976) recommend that egg-yolk should be replaced with blood plasma, if coagulase-positive staphylococci are to be detected directly. Smith and Baird-Parker (1964) recommend the addition of sulfamethazine to suppress the growth and swarming of Proteus species.

Culture Media; Media-Microbiological