An indicator organism or group of organisms is/are one whose numbers in a product reflects the success or failure of good manufacturing practices.
Indicator organisms are bacterial groups (or species) whose presence in foods, above a certain numerical limits, is considered to indicate exposure of food to conditions that might introduce hazardous organisms and/or allow proliferation of pathogenic or toxinogenic species.
microbiological safety and quality of foods. Indicator organisms include coliforms and faecal streptococci. The best example of indicator organisms are the coliforms. Coliform group is defined to include all aerobic and faculitative anaerobic, gram negative, non-spor forming, rod shaped species which ferment lactose with the production of acid and gas within 48 hours at 350C Coliform are either part of the normal flora of intestinal tract of man and animals or found in environments such as soil and plants. Coliform that are commonly found in the intestinal tracts of man and animals (faeces) are called faecal coliform and those coliforms that are normal inhabitants of soil and plants are called non faecal coliform.