MYP HiVegâ„¢ Agar Base (Phenol Red Polymyxin HiVegâ„¢ Agar Base) is recommended to isolate, identify and enumerate Staphylococci and Bacillus cereus from food. Typical mannitol fermentors produce yellow colonies and lecithinase activity is indicated by opaque zone around the colony. This medium is prepared by replacing animal peptones with vegetable defined peptones to avoid BSE/TSE risks associated with animal peptones.