EC(Eschirichia coli)broth

The original formulation described by Perry and Hajna¹ with Tryptose as the nitrogen source was subsequently substituted for Tryptone . The medium has been shown to be a reliable medium producing dependable results in 24 to 48 hours².

EC Broth is a selective medium for the differentiation of faecal coliforms and the confirmatory test for Escherichia coli from food and environmental samples^3,4. It is also suitable for the enumeration of presumptive E. coli in milk and milk products using the most probable number technique².

Escherichia coli is a common Gram-negative micro-organism which may be present in food and water samples. The presence of E. coli cells may be indicative of faecal contamination, although their ingestion does not necessarily have adverse effects on health. Nevertheless, certain strains are responsible for diarrhoeal disease and can also lead to more serious forms of illness.

The presence of E. coli in water is also regarded as a specific indicator of faecal pollution, but lack of rapid identification methods means that the non-specific group – faecal coliforms – is also used as the indicator of such pollution. In this regard, it is important to differentiate between coliforms of faecal origin and those from other sources.

The identification criterion for E. coli and faecal coliforms is the fermentation of lactose to acid and gas within 24-48 hours at 44-45.5°C, is dependent upon which method and/or material is used: