A subset of the coliform group characterised by ability to grow in selective culture media at a temperature of 44. 5ºC. The number of faecal coliform organisms in a sample is typically estimated by the Most Probable Number (MPN) method. The presence of faecal coliforms in a sample of a food is almost certainly evidence of contamination of the food with organisms of enteric origin. The organism Escherichia coli makes up most of the faecal coliforms, but further tests are required to identify the organism.