A box of ham sandwiches with mayonnaise, prepared by a person with a boil on his neck, is left out of the refrigerator for the on-call interns. Three doctors become violently ill approximately 2 hours after eating the sandwiches. Which of the following is the most likely cause?
Certain strains of staphylococci elaborate an enterotoxin that is frequently responsible for food poisoning. Typically, the toxin is produced when staphylococci grow on foods rich in carbohydrates and is present in the food when it is consumed. The resulting gastroenteritis is dependent only on the ingestion of toxin and not on bacterial multiplication in the GI tract. Characteristic symptoms are nausea, vomiting, abdominal cramps, and explosive diarrhea. The illness rarely lasts more than 24 hours. Campylobacter perfringens toxin contributes to a form of food poisoning, but the organism is ingested and grows in the patient, then releasing the toxin. Campylobacter perfringens also have toxins that can damage various tissues (gas gangrene). Staphylococcus aureus produces coagulase that clots plasma and does not contribute to S. aureus food poisoning. Penicillinase (b-lactamase) does not contribute to food poisoning symptoms. Leukocidin inactivates WBCs in the laboratory, but clinical significance is uncertain.
Clostridium perfringens toxin
Coagulase from S. aureus in the ham
Penicillinase given to inactivate penicillin in the pork
Staphylococcus aureus enterotoxin
Bacteria