Which statement is true regarding Vibrio cholerae?

Which statement is true regarding Vibrio cholerae?

• A. It is halophilic
• B. It is nonmotile
• C. Forms clear colonies on TCBS agar
• D. Produces a potent exotoxin causing severe diarrhea

Answer: (D)

Cholera toxin is a very potent enterotoxin produced by Vibrio cholerae. It is an AB5 toxin that ADP-ribosylates the Gs protein, keeping adenylate cyclase permanently active. This raises cAMP levels in intestinal epithelial cells, driving massive chloride secretion and water loss into the gut, which results in the characteristic severe, watery diarrhea. That makes the statement about a potent exotoxin causing severe diarrhea the best answer because it directly reflects the toxin’s role in disease. Vibrio cholerae is not nonmotile; it is motile with a polar flagellum. On TCBS agar, it does not form clear colonies; it ferments sucrose and typically yields bright yellow colonies. As for halophilicity, Vibrio species tolerate saline conditions but are not strictly halophilic in the sense of requiring high salt, so that feature isn’t the defining true characteristic here.

Cholera toxin is a very potent enterotoxin produced by Vibrio cholerae. It is an AB5 toxin that ADP-ribosylates the Gs protein, keeping adenylate cyclase permanently active. This raises cAMP levels in intestinal epithelial cells, driving massive chloride secretion and water loss into the gut, which results in the characteristic severe, watery diarrhea.

That makes the statement about a potent exotoxin causing severe diarrhea the best answer because it directly reflects the toxin’s role in disease. Vibrio cholerae is not nonmotile; it is motile with a polar flagellum. On TCBS agar, it does not form clear colonies; it ferments sucrose and typically yields bright yellow colonies. As for halophilicity, Vibrio species tolerate saline conditions but are not strictly halophilic in the sense of requiring high salt, so that feature isn’t the defining true characteristic here.