Bacterium
Enterotoxigenic E. coli (ETEC)
Toxin-driven watery traveler's diarrhea pathotype
en-ter-oh-tok-sih-JEN-ik
High-yield clue
Non-invasive watery (secretory) diarrhea from heat-labile (LT) and heat-stable (ST) enterotoxins is the defining pathotype clue.
Overview
A diarrheagenic pathotype of Escherichia coli defined by its production of secretory enterotoxins rather than by invasion. It is the leading cause of travelers' diarrhea and a major cause of childhood watery diarrhea in low-resource settings.
Classification
- Gram-negative
- Diarrheagenic E. coli pathotype
- Toxin-mediated (non-invasive)
- Enterobacterales
Lab & identification clues
- LT and ST enterotoxin gene detection (PCR) vocabulary
- Colonization-factor fimbriae adhesion concept
- No mucosal invasion (non-inflammatory stool) framing
- Not distinguished from flora by routine stool culture
Associations
- Travelers' diarrhea study association
- Fecal-oral, contaminated food and water transmission
- LT raises cAMP (cholera-toxin-like mechanism)
- ST raises cGMP driving fluid secretion
Commonly confused with
- Vibrio cholerae (LT resembles cholera toxin)
- Shiga toxin-producing E. coli (STEC)
Your notes
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.