Question

One of the causative organism responsible for toxi-infection through milk products is

• A. Bacillus subtilis
• B. Pseudomonas aeruginosa
• C. Clostridium perfringens
• D. Klebsiella pneumoniae

Hint:

Toxi-infections like those caused by Clostridium perfringens are characterized by high ingestion doses of vegetative cells, with toxins released in vivo during sporulation rather than pre-formed in food.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
To classify foodborne illnesses accurately, we must distinguish between foodborne infections, foodborne intoxications, and toxi-infections.
A foodborne infection occurs when viable pathogenic cells are ingested, which subsequently colonize and invade the host tissues.
A foodborne intoxication occurs when pre-formed microbial toxins are ingested directly from the food matrix.
A toxi-infection (or toxin-mediated infection) occurs when vegetative cells or spores are ingested, survive gastric passage, and produce enterotoxins inside the host intestine.

Step 2: Detailed Explanation:
Among the options provided, Clostridium perfringens is a classic spore-forming, anaerobic, Gram-positive rod that causes toxi-infections.
When contaminated dairy products or other foods are consumed, the vegetative cells of Clostridium perfringens pass into the small intestine.
Due to the hostile intestinal environment, these vegetative cells undergo rapid sporulation.
During the sporulation process in the colon, the cells synthesize and release the Clostridium perfringens enterotoxin (CPE).
This enterotoxin binds to specific claudin receptors on the epithelial cell membranes of the host's intestine.
This binding alters membrane permeability, leading to fluid accumulation, cell lysis, and severe diarrheal symptoms.
Conversely, the other organisms listed do not produce this specific clinical picture:
Bacillus subtilis is primarily a non-pathogenic saprophyte associated with dairy spoilage defects, such as ropiness or sweet curdling.
Pseudomonas aeruginosa is an opportunistic pathogen that causes spoilage (lipolysis and proteolysis) but is not a primary foodborne pathogen.
Klebsiella pneumoniae is an environmental coliform that can cause bovine mastitis but does not cause classical foodborne toxi-infections.

Step 3: Final Answer:
Therefore, Clostridium perfringens is the causative agent of foodborne toxi-infections.