MUG Sorbitol Agar

MUG Sorbitol Agar is used for the isolation and identification of enteropathogenic Escherichia coli associated with infant diarrhea by fluorogenic method. This medium is used for detecting or differentiating enteropathogenic E. coli (EPEC) in water by a fluorogenic method. Sorbitol degrading microorganisms produce pink to red colonies while sorbitol negative colonies are colourless. MUG (4-Methyl-umbellifery ß-D-Glucuronide) is converted into a fluorescent product 4-Methyl-umbelliferone by the ß-D glucuronidase-producing organisms. However enteropathogenic E. coli (in contrast to commensal E. coli strains) does not synthesize this enzyme and thus when its colonies are exposed to long wave UV light, no fluorescence is observed. It has reported that some Enterobacteriaceae and Pseudomonas aeruginosa are inhibited on this medium when incubated in a CO2-enriched atmosphere.