Brilliant Green Agar w/ Phosphates

Principle And Interpretation

Salmonella species cause many types of infections, from mild self-limiting gastroenteritis to life threatening typhoid fever. The most common form of Salmonella disease is self-limiting gastroenteritis with fever lasting less than 2 days and diarrhoea lasting less than 7 days.(8) This medium contains peptic digest of animal tissue, meat extract and yeast extract as sources of carbon, nitrogen, vitamins, amino acids and essential nutrients. The 2 sugars, namely lactose and sucrose serve as energy sources. Fermentation of lactose and / or sucrose in the medium results in the formation of acidic pH which is detected by phenol red indicator. This medium is formulated as per the recommendation of Rijks Institute Voorde Volksgezondheld (National Institute for Public Health), Utrecht (1,2). It is widely accepted and used in ISO Standards (3,4,5) because of its improved performance with respect to recovery of smaller numbers of Salmonella species, inhibition of Escherichia coli Proteus species and Pseudomonas species (6). The medium can be further supplemented with sulphacetamide (1 g/l) and sodium mandelate (0.25 g/l) to inhibit contaminating microorganisms when the sample is suspected to be containing large number of competing organisms along with Salmonella species (7).