ABSTRACT
The group of thermotolerant coliforms, commonly called fecal coliforms, is a subgroup of the total coliform group and includes only members that are capable of fermenting lactose at 44.5°C to 45.5°C, with the production of gas. Escherichia coli is included both in the group of total coliforms as in that of thermotolerant coliforms. Its natural habitat is the intestinal tract of hot-blooded animals, although it may be introduced into foods via non-fecal sources. The classical method to perform total coliforms, thermotolerant coliforms and E. coli counts in water and foods is the most probable number technique, which includes the following steps: presumptive test. The methods of the International Organization for Standardization are applicable to products intended for human consumption or for the feeding of animals and to environmental samples in the area of food production and food handling.
