Abstract
A membrane filter-Endo agar method for enumerating Escherichia coli as distinct from other coliforms in drinking water was developed. Membranes containing coliform colonies are transferred to nutrient agar containing 4-methyl umbelliferyl-.beta.-D-glucuronide (MUG) and incubated at 3.degree. C for 4 h. The MUG is hydrolyzed by the glucuronidase of E. coli and the fluorogenic product is visualized. The method recovered 98% of E. coli without false positives and is proposed as an additional test in routine water examination for the detection of pollution.