Which bacterium is known to produce enterotoxins causing secretory diarrhea?

Which bacterium is known to produce enterotoxins causing secretory diarrhea?

• A. Staphylococcus aureus
• B. Clostridium difficile
• C. Bacillus anthracis
• D. Escherichia coli

Answer: (D)

Secretory diarrhea happens when toxins disrupt ion transport in enterocytes, driving water into the intestinal lumen. Escherichia coli, particularly the enterotoxigenic strains, produces toxins that mimic host signaling molecules and raise cAMP (heat-labile toxin) or cGMP (heat-stable toxin). This triggers chloride secretion via CFTR and reduces sodium absorption, resulting in watery, non-bloody stools typical of secretory diarrhea. Other listed organisms have different toxin profiles: Staphylococcus aureus mainly causes rapid vomiting from preformed enterotoxins, not the classic secretory diarrhoea pattern; Clostridium difficile toxins A and B cause colitis with inflammation and pseudomembranes rather than straightforward secretory diarrhoea; Bacillus anthracis toxins drive systemic effects rather than intestinal secretory diarrhoea. So the bacterium best known for enterotoxins that cause secretory diarrhoea is Escherichia coli.

Secretory diarrhea happens when toxins disrupt ion transport in enterocytes, driving water into the intestinal lumen. Escherichia coli, particularly the enterotoxigenic strains, produces toxins that mimic host signaling molecules and raise cAMP (heat-labile toxin) or cGMP (heat-stable toxin). This triggers chloride secretion via CFTR and reduces sodium absorption, resulting in watery, non-bloody stools typical of secretory diarrhea.

Other listed organisms have different toxin profiles: Staphylococcus aureus mainly causes rapid vomiting from preformed enterotoxins, not the classic secretory diarrhoea pattern; Clostridium difficile toxins A and B cause colitis with inflammation and pseudomembranes rather than straightforward secretory diarrhoea; Bacillus anthracis toxins drive systemic effects rather than intestinal secretory diarrhoea. So the bacterium best known for enterotoxins that cause secretory diarrhoea is Escherichia coli.