Ingestion of contaminated foods that leads to exotoxin-mediated symmetric descending paralysis is characteristic of which organism?

• A. Clostridium difficile
• B. Vibrio vulnificus
• C. Staphylococcus aureus
• D. Clostridium botulinum

Answer: (D)

The toxin that fits this pattern is produced by Clostridium botulinum. Its botulinum toxin is a potent exotoxin that blocks acetylcholine release at the neuromuscular junction. It does this by cleaving SNARE proteins required for vesicle fusion, so acetylcholine cannot be released from presynaptic terminals. The result is a descending, symmetric flaccid paralysis that often begins with cranial nerve involvement (eye muscles, swallowing, speaking) and then progresses to the limbs.

This neurotoxic presentation after ingestion of contaminated foods is distinctive for botulinum toxin. The other organisms listed produce toxins that mainly cause foodborne gastroenteritis or wound infections, not this characteristic neuroparalytic syndrome.