MUG Nutrient HiCynth™ Agar

Principle And Interpretation

Escherichia coli is the member of faecal coliform group, presence of which in water indicates faecal contamination. These bacteria possess the enzyme ß-glucuronidase and are capable of cleaving the fluorogenic substrate 4-Methylumbelliferyl beta-D-Glucuronide (MUG) with the release of the corresponding fluorogen, 4-Methylumbelliferone (1). Therefore incorporation of MUG and subsequent fluoroscense is confirmatory for presence of E.coli with no further confirmation required (2). MUG Nutrient Agar is recommended for detection of E.coli in water and food samples by a fluorogenic method. Presumptive E.coli in the samples can be directly inoculated into the medium. MUG Nutrient HiCynth™ Agar is prepared by completely replacing animal peptones or vegetable peptones with chemically defined peptones to avoid BSE/TSE risks associated with animal peptones.

HiCynth™ Peptone No.1 and HiCynth™ Peptone No.5 provide nitrogenous compounds, carbanaceous compounds, long chain amino acids, vitamin B complex and other growth nutrients. MUG is cleaved by the enzyme beta-glucuronidase of E.coli to release 4-methylumbelliferone which produces visible green-blue fluorescence under long wave UV light (1). Some strains of Salmonella and Shigella species also produce glucuronidase (3).