Description
Amyl Aesculin Bile Salt Agar, AM 62, is a modification of the formula developed by Swan1, who suggested that the use of a medium containing bile salts and aesculin could be used as an alternative method to serological testing for the provisional identification of enterococci and Group D streptococci..
Beef extract and peptones derived from casein and gelatin, provide adequate nutrition for the more fastidious Group D streptococci which, together with enterococci, enables them to grow and exhibit tolerance to the substances present in ox gall, inhibitory to most other gram positive bacteria. These organisms, together with some members of the enterobacteiaceae, also have the capacity to hydrolyse the glycoside aesculin producing dextrose and aesculitin, the latter substance reacting with ferric ions to form a dark brown to black precipitate, thereby indicating aesculin hydrolysis.
