enterotoxigenic

Enterotoxigenic describes bacteria or strains that produce enterotoxins, toxins that act on the intestinal lining to disrupt fluid balance and cause diarrhea. The term is most often applied to enterotoxigenic Escherichia coli (ETEC), a leading cause of traveler's diarrhea and a common cause of diarrheal illness in children in low-resource settings. Enterotoxigenic organisms often carry plasmids with enterotoxin genes and may express colonization factors that promote adherence to intestinal epithelial cells.

In ETEC, the principal toxins are heat-labile toxin (LT) and heat-stable toxin (ST). LT is an AB5-like toxin that increases intracellular cyclic AMP by ADP-ribosylating the Gs subunit of adenylate cyclase, driving chloride secretion and water loss. ST activates guanylate cyclase, raising cyclic GMP and promoting secretion. Some strains produce only LT, only ST, or both. The resulting disease is typically a noninflammatory secretory diarrhea.

Clinical features include profuse watery diarrhea, abdominal cramps, nausea, and sometimes low-grade fever, with little systemic illness. Illness is usually self-limited over several days but can cause significant dehydration, especially in young children and travelers.

Diagnosis relies on clinical presentation supported by stool testing for enterotoxigenic strains or their toxins, using culture, toxin detection, or molecular assays. Treatment is primarily supportive, with oral rehydration and, in some settings, intravenous fluids. Antibiotics may reduce duration in certain contexts but are not universally indicated and should be guided by local guidelines.

Prevention emphasizes safe food and water, proper hand hygiene, and sanitation. Vaccines targeting ETEC and other enterotoxigenic pathogens are under development.