Rapid detection of Escherichia coli in urine samples by a new chromogenic beta-glucuronidase assay.

A new compound, indoxyl-beta-D-glucuronide, was assessed as a substrate for the rapid detection of Escherichia coli in urine. Incorporation of this compound into MacConkey agar allowed the direct differentiation of E. coli as deep blue colonies distinct from lactose and nonlactose fermenters. The sensitivity was 88 to 90%, and the specificity was 100%.