Bacillus cereus - Infection
Bacillus cereus
Emetic food poisoning
Intoxication caused by pre-formed cereulide, which is heat stable.
Spores survive initial cooking, and germinate if the food is not refrigerated; importantly, reheating does NOT kill the enterotoxin.
Commonly associated with rice and other starchy foods left at room-temperature for long periods of time.
Toxin produces nausea, abdominal cramps, and vomiting; in rare complications, liver failure occurs when large quantities impair mitochondrial fatty acid metabolism.
Quick: the incubation period < 6 hours after consumption, and illness duration < 24 hours.
Diarrheal food poisoning
Infection by vegetative cells that produce heat labile enterotoxin in the intestine.
Within the intestinal epithelial cells, the toxin increase the concentration of cyclic AMP.
The bacteria tend to reside on meats and vegetables.
They multiply in the gastrointestinal tract, where heat labile enterotoxin produces nausea, abdominal cramps, and watery diarrhea.
Slow: Incubation period is > 6 hours; duration > 24 hours.
Ocular infections
Associated with trauma, surgery, or bacteremia.
At least three toxins are associated with ocular infection: necrotic toxin, cereolysin, and phospholipase C. Interactions of these toxins, and perhaps factors, leads to rapid infection progression and eye loss.
Treatment: Clindamycin or vancomycin is urgent.
Severe pneumonia
Mimicks inhalation anthrax.
Intravenous catheter and CNS shunt infections, endocarditis, bacteremia, and meningitis.
Especially in immunocompromised patients.