Food intoxication
Introduction.
Food intoxication results from ingestion of bacterial toxins rather than from
ingestion of the bacteria themselves. Staphylococcal enterotoxins are heat and
acid resistant and survive cooking and ingestion.
Summary
Cause: Staphylococcus aureus
- Microscopy: Gram-positive cocci, clusters
- Symptoms: Severe vomiting, diarrhea, abdominal pain, nausea lasting
< 24 hours; onset abrupt (4 hrs)
- Transmission: Ingestion of contaminated meats, pastries, potato
salad
- Pathogenesis: Enterotoxin A or other types act as superantigens,
activating T-cells and mast cells. Cytokines, histamine and inflammation
cause symptoms
- Treatment: Fluid replacement; symptomatic
Cause:
Bacillus cereus
- Microscopy: Gram-positive rods, chains, endospores
- Symptoms: Vomiting, nausea, cramps (emetic form) lasting < 1 day
Diarrhea, nausea, cramps (diarrheal form) lasting > 1 day
- Transmission: contaminated food: rice (emetic) or meat,
vegetables, sauces (diarrheal)
- Pathogenesis: Heat-stable enterotoxin (produced in food);
heat-labile enterotoxin (produced in GI tract): activates adenylate cyclase.
Other virulence factors include cereolysin (hemolysin) & lecithinase
- Treatment: symptomatic