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- Enterovirulent E. coli (EEC) facts
- What are enterovirulent E. coli (EEC)?
- What are the symptoms caused by enterovirulent E. coli (EEC)?
- A new EEC group? (E. coli 0104:H4)
- How do enterovirulent E. coli groups cause disease?
- When should one seek medical care for enterovirulent E. coli infection?
- How are enterovirulent E. coli infections diagnosed?
- How are enterovirulent E. coli infections treated?
- How is self-care at home done for enterovirulent E. coli?
- What are the complications associated with enterovirulent E. coli (EEC)?
- How are enterovirulent E. coli (EEC) infections prevented?
- What are the prognoses (outcomes) of enterovirulentE. coli infections?
What are enterovirulent E. coli (EEC)?
Enterovirulent Escherichia coli (E. coli) are composed of a number of serotypes (strains of related bacteria identified by their slightly different antigenic structures) of bacteria that have a strong propensity to cause infections, initially in the gastrointestinal tract ("entero" in Greek means intestine; virulent means deadly or disease-causing). Enterovirulent Escherichia coli (EEC) are members of the bacterial genus Escherichia, named after T. Escherich, who first isolated the bacteria in 1885. The majority of the genus Escherichia is composed of one species termed "coli" (Latin for colon); however there are over 700 serotypes of this bacterial species. Many E. coli serotypes may cause infections other than in the intestine, but the focus of this article is on the enterovirulent groups (EEC groups), with symptoms of the disease primarily limited to the gastrointestinal tract.
Escherichia coli (E. coli) are gram-negative bacteria that are rod-shaped, have the ability to survive in aerobic and anaerobic environments (termed a facultative anaerobe), and may or may not produce flagella and pili (thin hair-like projections) depending on environmental needs.
E. coli strains are found worldwide and live in significant numbers in humans and other animals as part of the normal bacterial population found in their large intestines. The organisms have likely co-existed with humans for eons in the normal flora (bacterial populations usually found in healthy individuals) of human and other animal colons. However, among the 700 strains of E. coli, there are a few strains that cause disease. These E. coli strains are some of the most frequent causes of many common bacterial infections, including diarrhea, cholecystitis, bacteremia, cholangitis, urinary tract infection (UTI), traveler's diarrhea, and other clinical infections such as neonatal meningitis, pneumonia, abdominal abscesses, and hemolytic uremic syndrome (HUS).
A classic example of such an E. coli strain is E. coli 0157:H7. The name E. coli 0157:H7 seems complex; however scientists use the numbers and letters to specifically designate small differences in E. coli strains. The 0157 is the "O" serotype antigen that identifies one of the over 700 strains and the "H" of H7 represents the antigen type on the bacterium's flagella. Some E. coli also possess K antigens (protein/polysaccharide surface components) that have been used to identify certain strains. These designations (O, H, and K) may be used to identify strains causing specific diseases and have been utilized to identify outbreaks of disease.