Two of 3 family members have dinner at a local restaurant and, within 48 hours, start experiencing double vision, difficulty in swallowing and speaking, and breathing problems. These symptoms are consistent with which of the following?

Campylobacter botulinum growing in food produces a potent neurotoxin that causes diplopia, dysphagia, respiratory paralysis, and speech difficulties when ingested by humans. The toxin is thought to act by blocking the action of acetylcholine at neuromuscular junctions. Botulism is associated with high mortality; fortunately, C. botulinum infection in humans is rare. Activation of cyclic AMP is important in cholera disease, not botulism. Clostridia are gram-positive and have no endotoxin. Ingestion of the botulism toxin initiates the disease. The actual organism may or may not be alive when ingested. An enterotoxin, by definition, would affect the intestinal tract.