Bacillus cereus
| Categorization | |
|---|---|
| Cell Wall: Gram Positive | Shape: Spore-forming Rod |
| Metabolism: Obligate Aerobe | |
| Virulence Factors |
|---|
- Exotoxins
- Heat-labile Enterotoxin: Similar mechanism of action as that of V. Cholera toxin and requires 12-24hrs to cause infectious diarrhea
- Heat-stable Enterotoxin: Similar mechanism as the S. aureus enterotoxin and causes diarrhea with a much quicker onset of less than 8hrs
| Transmission |
|---|
- B. cereus spores can exist on grains such as rice and survive the cooking process. When left reheated for long periods the spores can germinate and grow, thus elaborating enterotoxins.
| Clinical Consequences |
|---|
- Food Poisoning: Depending on which enterotoxin dominates the picture, infectious diarrhea may occur with different kinetics. If heat-labile enterotoxin dominates then diarrhea with onset 12-24hrs occurs which is generally watery. If heat-stable enterotoxin dominates then diarrhea with onset of less than 8hrs occurs together with nausea, vomiting, and abdominal pain.
| Treatment |
|---|
- Supportive therapy: Antibiotics are useless as the diarrhea is caused solely by ingestion of pre-formed enterotoxins.