Coliforms,Enterobacteriacaeable to ferment lactose (lactose positiveEnterobacteriacae), are bacteria present not only in human and warm blooded animals intestinal flora but also 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 ofEscherichia coliand thermotolerantKlebsiella. Strict regulations exist forE. coli/coliform presence in water samples.
This can be explained by the importance of these germs in determining drinking water safety and process efficiency of treatment, storage and distribution.