Main topic :
Control of Shiga Toxin producing Escherichia coli (STEC) in the food industry
SERGENTET D. 1,2
1 University of Lyon, Bacterial Opportunistic Pathogens and Environment Research Group, UMR5557 Ecologie Microbienne Lyon, CNRS (National Center of Scientific Research), VetAgro Sup, , France; 2 University of Lyon, VetAgro Sup—veterinary campus, French National Reference Laboratory for Escherichia coli including Shiga toxin-producing E. coli (NRL-STEC), Laboratoire d’Etudes des Microorganismes Alimentaires Pathogènes, , France
Pathogenic Shiga Toxin-producing Escherichia coli (STEC) are food-borne zoonotic bacteria associated with large-scale epidemics that represent a major public health problem. They are very frequently associated with severe forms of infections such as bloody diarrhea, and in very severe cases, hemolytic uremic syndrome (HUS). HUS is the leading cause of renal failure in children under 3 years. In 2010, WHO estimated that foodborne STEC caused more than 1.2 million illnesses, 128 deaths, and nearly 13 000 Disability Adjusted Life Years (DALYs). Human STEC infection is most often linked to the ingestion of contaminated cattle products, such as beef, raw milk and raw milk cheese, or with water or vegetables directly contaminated from cattle. The estimated STEC infectious dose is very low: between 5 and 50 viable cells. To date, there is no effective treatment to cure or prevent these human infections.
Cattle are the main reservoir of STEC. Infected cattle can carry the bacteria in their gastrointestinal tract without any symptoms of disease and shed them in their feces. Detailed investigations have shown that without observance of appropriate cleaning steps and udder hygiene practices, fecal matter can contaminate the cow’s teats and udders, which in turn can contaminate carcasses, the milk during the milking process and vegetables. For this reason, STEC can potentially be found in raw milk, raw milk products, water or soiled vegetables. Human infection is typically acquired through the ingestion of contaminated foods.
The application of combined control measures throughout the food chain such as good hygiene practices, and hazard analysis critical control point (HACCP) principles are necessary in order to limit fecal contamination. The detection of STEC in finished products and during the manufacturing process has an important role as part of verification plans, to confirm that practices and procedures described in the food safety program are successful.
Only preventive measures implemented throughout the chain from the farm to the consumer can reduce the risk of human infection.
The presentation will aim to review the current state of knowledge on STECs and to highlight the major health safety issues involved. The detection methods as well as the tools for surveillance and control of these STEC will also be discussed.