Important ingredients: 6.5% salt, dextrose, bromcresol purple
Differential/Selective: used to test for salt tolerance and can be used to identify enterococcal group D streptococci. NaCl is a selective agent and those organisms that can grow in higher salt concentrations also ferment the dextrose in the media. This causes acid formation causing the bromcresol purple indicator to turn yellow.
(A) Entercoccus faecalis: Color change from purple to yellow indicating fermentation of the dextrose and salt tolerance.
(B) Streptococcus bovis: No color change or growth.