Question

Which of the following is most likely to cause food toxi-infection due to the production of heat-stable enterotoxins?

• A. Clostridium perfringens
• B. Streptococcus uberis
• C. Bacillus cereus
• D. Listeria monocytogenes

Hint:

Remember that Bacillus cereus produces a highly heat-stable emetic toxin (cereulide) that can withstand temperatures up to \(121^{\circ}\text{C}\) for 90 minutes, making it a major concern in heat-processed foods.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Food toxico-infections (or toxi-infections) occur when live pathogenic bacteria are ingested, which then multiply and release toxins within the human digestive tract.

Step 2: Detailed Explanation:
- Bacillus cereus is an aerobic, endospore-forming pathogen. It causes two distinct types of foodborne illness:
1. Diarrheal type (toxi-infection): Caused by a heat-labile enterotoxin produced in the small intestine during vegetative growth and sporulation.
2. Emetic type (intoxication): Caused by a highly heat-stable, acid-resistant peptide toxin (cereulide) produced pre-formed in the food.
- Both toxins make Bacillus cereus a prominent cause of foodborne illness associated with heat-treated foods.
- Clostridium perfringens causes diarrheal illness but produces enterotoxins that are generally heat-labile.
- Streptococcus uberis is an environmental mastitis pathogen, and Listeria monocytogenes is an intracellular pathogen that does not produce enterotoxins.

Step 3: Final Answer
The organism most likely to cause foodborne illness through heat-stable toxins is Bacillus cereus.