Bacillus cereus

Description and health risks:

Bacillus cereus is a bacterium, certain pathogenic strains of which can cause foodborne illnesses. The symptoms depend on the type of toxin produced:

• Emetic form (cereulide toxin):
  Nausea, vomiting, and abdominal pain (occasionally accompanied by mild diarrhea) usually occur 30 minutes to 6 hours after consuming contaminated food.
• Diarrheal form (other toxin):
  Watery diarrhea, abdominal cramps, and sometimes nausea usually occur 6 to 24 hours after consuming contaminated food.

In rare cases, more severe forms may occur, including:

• Metabolic disorders
• Liver damage
• Rapid deterioration of general condition requiring urgent medical attention

These symptoms can be more severe in high-risk groups (YOPI): infants and young children (Young), elderly people (Old), pregnant women (Pregnant), and immunosuppressed individuals (Immunosuppressed).

In infants, ingestion of the cereulide toxin can cause acute food poisoning, sometimes severe, presenting as refusal to feed, unusual crying or signs of abdominal pain, excessive fatigue or lethargy, and signs of dehydration (dry mouth, reduced number of wet diapers).

Persons who have consumed a contaminated product and exhibit these symptoms are advised to consult a doctor and report the consumption. The severity of symptoms may vary depending on the individual and the severity of the intoxication.

Resistance of the Bacterium and the Toxin

Bacillus cereus is highly resistant to drying, long storage periods, and heat; it can survive typical cooking temperatures that kill most other bacteria.

Under certain conditions, particularly during slow cooling or when cooked foods are cooled and reheated one or more times (especially rice and pasta), the bacteria can multiply and produce toxins.

The cereulide toxin is thermostable: it is not destroyed by cooking, by preparing milk from powder (even with hot or boiling water), or by boiling reconstituted milk.
For this reason, contaminated powders must not be consumed, as the toxin can persist after reconstitution.

Foods at Risk?

Starch- or protein-rich foods are particularly susceptible to contamination with Bacillus cereus and/or the cereulide toxin. These include Rice, Pasta, Potato-based products, Dairy products (especially powdered milk), Spice mixes, Ready-to-eat meals.