Description
The formulation of Sorbitol MacConkey Agar, AM 128, is identical to that of MacConkey Agar No. 3, AM 97, with the exception that the lactose component of the latter has been replaced by the carbohydrate sorbitol, allowing non-sorbitol fermenting enteric organisms to be detected.
This formulation is based on that of Rappaport and Henig1 who used the medium as a means of differentiating between sorbitol and non-sorbitol fermenting enteric bacteria, a method followed by March and Ratnam2 who demonstrated that use of the medium was suitable as a relatively simple, inexpensive means of screening for the presence of Escherichia coli O157:H7 in faeces and in food samples.
