Profuse watery diarrhea (“rice water stools”), leading to dramatic fluid loss, severe dehydration

Question:- Profuse watery diarrhea (“rice water stools”), leading to dramatic fluid loss, severe dehydration, and hypotension that frequently leads to death, is the hallmark of which toxin activity?

a. Cholera toxin b. Enteric endotoxin c. Shiga toxin d. Toxin A

Answer:- a. Cholera toxin

The amounts of the described, profuse, watery diarrhea that may result in fatal dehydration and also hypotension are typical to the characteristic of cholera toxin activity. The Vibrio cholera bacterium releases the Cholera toxin. It binds to the adenylate cyclase that in turn triggers the overproduction of cAMP in intestinal epithelial cells. This results in the release of H2O, Na+, K+, Cl-, and also HCO3- into the intestinal lumen. This leads to an intolerable watery diarrhoea known as rice water stools that can lead to the fluid loss of about 1 litre in an hour. In these cases, such extreme state of dehydration and subsequent cardiovascular collapse may be very lethal unless immediately alleviated with the fluid replacement containing electrolytes. The mechanisms of action vary greatly among enteral endotoxins, Shiga toxin and Toxin A are not known for eliciting such severe yet profound losses in the fluid as well as electrolytes that occur quickly . Thus the most appropriate clinical description is that of cholera toxin action.