1 Answers
The concept of minimal infective dose has traditionally been used for bacteria that contaminate foods that cause infection in or from the digestive tract. MID was defined as the number of bacteria ingested from which a pathology is observed in the consumer. Examples such as this are found in textbooks: to cause gastrointestinal disorders, the food must contain more than 100,000 Salmonella per gram. However, in such a formulation, we immediately see an inaccuracy: to know the dose ingested, concentration is not enough. It is also necessary to know the mass of the portion:
where:
Nevertheless, this formulation has served as a basis for reasoning to establish the maximum concentrations permitted by the microbiological regulatory criteria intended to protect the health of consumers. Thus in 1992, as the outbreaks previously caused by Listeria monocytogenes involved only food containing more than 1000 L. monocytogenes cells per gram, lawmakers on both sides of the Atlantic - keeping a margin of safety - fixed its maximum concentration at 100 L. monocytogenes per gram.