CLED is preferable to Mac Conkey's bile-salt lactose medium for the culture of coliform and other bacteria from infected urine. Like McConkey medium, it distinguishes between lactose-fermenting (yellow) and lactose non-fermenting (blue, grey or green) colonies, inhibits the swarming of proteus and shows the greenish colour, matt surface and rough periphery of pseudomonas colonies. However, it has the advantage of suppoing the growth of ceain staphylococci, streptococci and candidas that fail to grow on MacConkey. Ref: Practical Medical Microbiology by Mackie McCaney; 14th edition