Escherichia coli is a Gram-negative bacillus with polar flagella1 (at one of its poles). There are many varieties of Escherichia coli. Most are not pathogenic and are present in the normal digestive flora.
Escherichia coli is most often implicated in faecal-oral infections and is the agent of tourista2 (traveller’s diarrhea). As the name suggests, tourista is traveler’s diarrhea, which very often manifests as gastroenteritis, abdominal cramps, nausea, vomiting, diarrhea.
Enterotoxigenic Escherichia coli is by far the most common cause of bacterial diarrhea in travelers (over 50% of cases). However, other bacterial agents can mimic the same symptoms, including shigellosis, salmonellosis, Campylobacter, Aeromonas, Vibrio cholerae, for example.