Coliforms, Enterobacteriacae able to ferment lactose (lactose positive Enterobacteriacae), are bacteria present in human and warm blooded animals intestinal flora, in the soil and water. Coliforms are proof of organic, environmental or faecal contamination. Faecal contamination, due to coliforms coming from animal waste, consists mainly of Escherichia coli and thermotolerant Klebsiella.
Strict regulations exist for E. coli/coliform presence in water and food samples. This can be explained by the importance of these germs in determining water and food safety. E. coli can contaminate drinking water when the water treatment system is inadequate or during periods of very high rainfalls. Monitoring of food and water production is essential. High contamination may lead to suspension of the water supply and food recall by supermarkets.
In the U.S.A. the EPA recommendations through the Total Coliform Rule (TRC) are:
• <1.000 CFU/100 mL for a fishing and boating water quality.
• <100 CFU/100 mL for a body-contact recreation water quality.
• <1 CFU/100 mL for a drinking water quality.
1. Simultaneous detection and differentiation: CHROMagar™ ECC allows simultaneous detection and differentiation between E. coli and coliform in one medium! This is helpful to determine if there is organic contamination (coliforms) or faecal contamination (E. coli). The use of this technique involves less work in comparison with traditional methods (MI Agar).
2. Easy to read thanks to the high colour contrast between colonies. There is no mixing of both colors (unlike some other chromogenic media on the market). Colonies are either mauve or blue (no metallic blue nor purple).