| abstract |
A solid growth plating medium in which Shigella organisms will grow and form colonies in the medium, and substantially, other microorganisms are inhibited or their colonies are differentiated from Shigella organisms. In one embodiment of the invention, colonies produced by Shigella appear with the color of the plating medium, usually a clear off-white color, that can be readily observed. In another embodiment, the fact that Shigella boydii and Shigella sonnei produce the enzyme alpha-galactosidase, but most Shigella dysenteriae and Shigella flexneri strains do not, is utilized with a chromogenic substrate to produce colonies of these microorganisms of a distinguishing color. |