Indicator organisms, such as coliform, Enterobacteriaceae, and generic Escherichia coli, are used extensively to indicate the potential presence of pathogenic organisms, as well as a failure in sanitation or process. This article reviews traditional and novel method for the detection of these indicator organisms as well as the detection of the various strains of pathogenic E. coli. The article emphasizes new rapid methods that can enhance, simplify, and allow for rapid results.