Question

Name the emetic toxin produced by Bacillus cereus

• A. Cerrulide
• B. Prodigiocin
• C. Aletrnarin
• D. Glyceride

Hint:

Cereulide is a pre-formed heat-stable toxin causing rapid-onset vomiting (emetic type), whereas the diarrheal type is caused by heat-labile enterotoxins produced in the intestine.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Bacillus cereus is a spore-forming bacterium responsible for two distinct types of food poisoning: diarrheal and emetic (vomiting).
These syndromes are caused by different toxins produced during bacterial growth.

Step 2: Detailed Explanation:
The emetic syndrome of Bacillus cereus is caused by a highly stable, pre-formed toxin:
- Cereulide (spelled Cerrulide in the question): This is a small, ring-shaped dodecadepsipeptide.
It is highly resistant to heat (surviving 121$^{\circ}$C for 30 minutes), proteolysis, and acid conditions, meaning it remains active even after cooking and passing through the stomach.
It acts by binding to 5-$HT_3$ receptors, stimulating the vagus nerve and triggering vomiting.
- Prodigiosin (spelled Prodigiocin): This is a red pigment produced by Serratia marcescens, not a toxin of Bacillus cereus.
- Alternariol (spelled Aletrnarin): This is a mycotoxin produced by Alternaria molds.
Thus, the correct emetic toxin of Bacillus cereus is cereulide.

Step 3: Final Answer
The correct option is (A).