Question

Which among the following is responsible for foodborne toxi- infection?

• A. Vibrio parahemolyticus
• B. Yersinia enterocolitica
• C. Clostridium botulinum
• D. Clostridium perfringens

Hint:

Remember the triad of foodborne illnesses:
1. Intoxication: Toxin is made in food before eating (e.g., S. aureus, C. botulinum).
2. Infection: Bacteria grow and invade the host tissues (e.g., Salmonella, Listeria).
3. Toxi-infection: Bacteria are eaten alive and then release toxins inside the gut (e.g., C. perfringens, V. cholerae).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Foodborne microbial illnesses are broadly classified into three categories: foodborne infections, foodborne intoxications, and foodborne toxi-infections (or toxicoinfections).
A toxi-infection occurs when a host ingests viable vegetative cells or spores of a pathogen.
These microorganisms do not cause illness merely by colonizing or invading the tissues, nor do they rely on pre-formed toxins in the food.
Instead, they produce enterotoxins inside the host's intestinal tract during sporulation or growth, leading to illness.
Detailed Explanation:
Among the options provided, Clostridium perfringens is a classic example of an organism causing a foodborne toxi-infection.
When large numbers of vegetative cells of Clostridium perfringens (typically $> 10^6$ cells per gram of food) are ingested, they survive the acidic environment of the stomach and pass into the small intestine.
In the alkaline environment of the intestine, these cells undergo rapid sporulation.
During the process of sporulation, a specific enterotoxin called Clostridium perfringens enterotoxin (CPE) is synthesized and accumulates inside the cell.
Upon complete sporulation, the mother cell lyses to release the mature spore, simultaneously releasing the CPE into the intestinal lumen.
The CPE then binds to claudin receptors on the epithelial cell tight junctions of the host intestine, causing pore formation, cell death, and acute diarrhea.
Let us evaluate the other options:
Vibrio parahaemolyticus and Yersinia enterocolitica primarily cause foodborne infections where the viable cells actively colonize and invade the intestinal mucosa.
Clostridium botulinum causes foodborne intoxication, as the highly lethal neurotoxin is pre-formed in the food product during anaerobic bacterial growth and is ingested directly.

Step 2: Final Answer:
Thus, Clostridium perfringens is the pathogen responsible for foodborne toxi-infection.