Salt Agar, Modified

Salt Agar, Modified is recommended for isolation and differentiation of the enterococcal group D Streptococci from non enterococcal group D Streptococci based on salt tolerance. Medium containing 6.5% sodium chloride is used to differentiate Enterococci by determining salt tolerance of bile esculin positive and catalase negative cocci. High salt content of this medium acts as a differential and selective agent by interfering with membrane permeability and osmotic equilibrium. Enterococcal group D Streptococcus species (Enterococcus faecalis, Enterococcus faecium, Enterococcus durans and Enterococcus avium) can be easily differentiated from the non-enterococcal species like Streptococcus bovis, Streptococcus equines, by the 6.5% sodium chloride tolerance test.