What is E. Coli?
E. coli (Escherigia Coli) is a group of bacterial strains known for many decades to cause illness in humans. In 1885, German bacteriologist Theodor Escherich isolated the first strain. Today, hundreds of E. coli strains are known. The E. coli bacteria, also known as fecal coliform bacteria because it lives in intestinal contents, including feces, are a genetic relative of the dangerous salmonella pathogen. The genera Escherichia and Salmonella diverged around 102 million years ago, at the time when mammals and birds diverged genetically. Mammals and birds are host species of Escherigia and Salmonella, respectively. E. coli and salmonella were discovered in the same year, 1885. E. coli was isolated by German bacteriologist Theodor Escherich. E. coli O157:H7, E. coli O104:H4 and other deadly strains belong to a family of bacteria that has evolved since the 1960s, when scientists believe E. coli and another bacteria, shigella, met and swapped genes. This created a form of E. coli that secretes the dangerous shiga toxin. Today, known E. coli strains number in the hundreds. Some strains produce enzymes that can destroy many antibiotics, including all penicillins.
None of these strains affects the taste, smell, or appearance of food. Read more: Now antibiotic-resistant bacteria are found in river water: Discovery of E.coli strains sparks concerns over growing threat of superbugs.
The E. coli strain most commonly linked with foodborne outbreaks of illness is known as Shiga toxin-producing E. coli O157:H7. The federal Centers for Disease Control and Prevention estimates that Shiga toxin-producing E. coli causes hundreds of thousands of poisonings each year in the United States, with thousands of hospitalizations and scores of deaths. Hereafter, we will use the term “E. coli” to refer solely to the most commonly harmful strains of Escherichia coli bacteria, most specifically Shiga toxin-producing E. coli O157:H7 and Shiga toxin-producing E. coli O104:H4.
In the mid-1990s, the federal government declared E. coli “an adulterant” in restaurant-served beef – putting E. coli on the same illegal footing as hazardous chemicals in food or foreign objects in food. After that, it was 7 years until E. coli presence in U.S. ground beef peaked. Since then, it is down some 80 percent. However, during the same time, E. coli rates were rising in other food commodities, such as spinach and lettuce, according to the USDA Food Safety and Inspection Service.