Wilson Blair Agar w/ BG

Wilson Blair Agar w/ BG is recommended for isolation and preliminary identification of Salmonella typhi from clinical specimens. Brilliant green dye inhibits all gram-positive bacteria. Dextrose is the fermentable carbohydrate. Ferrous sulphate is an indicator of H2S production. Bismuth is a heavy metal which is inhibitory to most gram-negative enteric bacilli other than Salmonella. Ferrous sulphate is reduced by Salmonella species in presence of bismuth sulphite and dextrose to form iron sulphide, indicated by black coloured colonies.