Index organisms: is one whose presence implies the possible occurance of a similar but pathogenic organism.E. coliis used an index organism and its presence indicates possible presence of pathogenic enteriobacteriacea eg.salmonellae species.
Food poisoning organisms
those which cause the disease by infection
those which produce toxin in food
Those which cause infection must grow in food in large numbers and cause infection when consumed together with food. The most most common microorganisms includes salmonella tyhimurrium, entropathogenicE.coli,Vibrio parahaemolyticus etc. Those which cause intoxication must grow in food large numbers and produce enough toxin and when consumed together with food cause intoxication.The most common microorganism in this group are clostridium botulinium,staphylococcus and toxigenic
fungi eg. Aspergillus flavus.
Organisms whose presence in sall numbers in food and when consumed can cause infection. In this case the food acts as a