Mannitol Salt Broth is recommended for selective isolation of presumptive pathogenic Staphylococci. Pathogenic staphylococci ferment mannitol and produce a yellow coloured medium. Most coagulase-negative species of Staphylococci and Micrococci do not ferment mannitol and therefore the medium remains red in colour. Presumptive Staphylococcus showing yellow coloured medium should be further tested for production of coagulase.
1. Leifson, 1933, J. Bact., 25:329. 2.MacFaddin J., 1985, Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria, Vol. I, Williams and Wilkins, Baltimore