Escherichia coli, commonly known as E. coli, is a gram-negative bacteria that belongs to the Enterobacteriaceae family. This bacteria is highly infectious and is responsible for causing more illnesses in humans than any other bacteria. It was first identified in the human colon by the renowned German bacteriologist Theodor Escherich in 1885. Dr. Escherich’s research revealed that only specific strains of E. coli are responsible for causing diarrhea and gastroenteritis. Originally named Bacterium coli, the species was later renamed in honor of Dr. Escherich’s significant contributions to its study.
Serotypes of E. coli
E. coli is a bacteria that has been extensively researched due to its significance in human health. With over 700 identified serotypes or strains, E. coli exhibits a wide range of variations. While there are some potentially harmful strains, it should be noted that beneficial or harmless strains of E. coli are much more prevalent. Although there are bacterial species that pose greater risks than E. coli, they are either less common or can be effectively managed through vaccination and avoidance strategies. Unfortunately, there is currently no vaccine available for E. coli, making complete avoidance of the bacteria impossible.
Types of E. coli That Cause Illness
Pathogenic strains of E. coli are responsible for causing various illnesses. These strains are classified into different pathotypes based on their characteristics. Among these pathotypes, six strains, known as diarrheagenic E. coli, are specifically associated with causing diarrhea. However, the most widely recognized pathotype is Shiga toxin-producing E. coli (STEC), which is also referred to as Verocytotoxin-producing E. coli (VTEC) or enterohemorrhagic E. coli (EHEC).
STEC is particularly concerning as it is the strain most likely to cause illness when consuming contaminated food or beverages. In laboratory settings, this particular strain can be easily identified due to its distinct green sheen on common types of agar plates.