Question

Which of the following are responsible for food infection

• A. Bacillus cereus and Clostridium botulinum
• B. Listeria monocytogenes and Vibrio parahemolyticus
• C. Clostridium botulinum and Clostridium perfringens
• D. Staphylococcus aureus and Bacillus cereus

Hint:

To easily differentiate these concepts:
- Food Infection = Live bacteria multiply inside the body (e.g., Listeria, Salmonella, Vibrio, Shigella).
- Food Intoxication = Preformed toxin ingested from food (e.g., Clostridium botulinum, Staphylococcus aureus).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Foodborne illnesses are broadly classified into food infections and food intoxications.
- Afood infection occurs when viable pathogenic microorganisms are ingested through contaminated food.
These pathogens then colonize, multiply, and invade the host's intestinal mucosa or other tissues, causing illness.
- Afood intoxication occurs when a microorganism grows in the food and produces a toxin before consumption.
The ingestion of this preformed toxin causes the illness, and the presence of viable cells is not required to produce symptoms.

Step 2: Detailed Explanation:
Let us evaluate the organisms listed in the options:
- Listeria monocytogenes is an intracellular pathogen that causes listeriosis.
Upon ingestion, the viable cells invade the intestinal epithelium and can spread to the central nervous system or placenta.
- Vibrio parahaemolyticus is a halophilic bacterium that infects the gastrointestinal tract, requiring the multiplication of living cells in the intestine.
Therefore, the pair in Option (B) represents pathogens that cause food infections.
Let us review the other options:
- Clostridium botulinum produces a highly potent neurotoxin preformed in anaerobic food environments, causing food intoxication.
- Staphylococcus aureus produces heat-stable enterotoxins preformed in food, causing food intoxication.
- Bacillus cereus can cause both, but its emetic form is a classic food intoxication mediated by the preformed toxin cereulide.
- Clostridium perfringens causes a toxicoinfection, where enterotoxins are produced during sporulation inside the intestine, which differs from a pure food infection.

Step 3: Final Answer:
Listeria monocytogenes and Vibrio parahaemolyticus are responsible for causing food infections.