Escherichia coli is a generally harmless bacteria living in the intestinal tract of animals and humans. However, there are species of this bacterium that cause diseases in humans. E. coli O157: H7 bacteria produce two separate toxins and are among the most dangerous foodborne pathogenic bacteria known. Especially in children and the elderly, and people living with immune system problems can easily form the disease. The first symptoms of the disease are high fever, abdominal pain, vomiting and non-bloody diarrhea.

Escherichia coli O157: The source of H7 is mainly cattle. It spreads to the soil, water, meat and shortly to the whole environment through feces. This bacteria is transmitted to humans in many ways and causes diseases. While skinning or removing internal organs of slaughtered animals, this bacterium is transmitted to meat or passed on to humans during contact with E. coli O157: H7 infected animals. Also E. coli O157: H7 contaminated fertilizers carry this bacteria to the agricultural areas where they are used. In addition, when E. coli O157: H7 contaminated water is used in cultivated areas, this bacterium can easily spread to food products.

E. coli O157: The leading cause of poisoning caused by H7 is meat products, raw milk and cheese. In addition, fruit juices, salads, salad dressings, yogurt and freshly squeezed fruit juices play a role in E. coli O157: H7 poisoning.

E. coli O157: Analysis for the detection of H7 bacteria are two groups of classical and rapid methods. Conventional methods consist of selective enrichment and seeding in solid medium and are carried out in the form of non-existent tests.

In advanced laboratories, analyzes for the determination of E. coli O157: H7 are carried out within the framework of microbiological analyzes. These studies are based on domestic and foreign standards. According to Turkish Food Codex, the presence of E. coli O157: H7 bacteria in foods is investigated in 25 gram sample.