Which organism causes illness with rapid onset and is associated with preformed toxins?

• A. Salmonella
• B. Staphylococcus aureus
• C. Vibrio
• D. Escherichia coli

Answer: (B)

Illness that starts quickly after eating and is linked to preformed toxins means the toxin is already in the food when consumed, so symptoms appear within hours. Staphylococcus aureus is the classic culprit because it can produce enterotoxins in food before you eat it. These toxins are heat-stable, so cooking may not neutralize them, allowing rapid onset of symptoms like vomiting and abdominal cramps soon after ingestion.

Other organisms listed typically cause illness by infection or toxin production after the bacteria have been ingested and begun to act in the gut, which usually leads to a longer incubation and symptoms such as diarrhea and fever. That difference in timing helps distinguish the preformed-toxin scenario from others.