Bacillus cereus

Bacillus cereus is a facultative anaerobic spore forming bacteria. It is widespread in nature and in foods, especially in the spore state.

Sources of the organism:

• Soil
• Unpasteurized milk
• Cereals and starches
• Herbs and spices

Associated foods:

• Cooked vegetables and meat
• Cooked rice and fried rice
• Starchy foods (potato, pasta)
• Food mixtures (soups, casseroles, sauces)
• Puddings

Microorganism Characteristics: Gram positive facultative anaerobic spore forming rod

The Disease: Bacillus cereus can cause two distinct types of illnesses: 1) a diarrheal illness with an incubation time of approximately 10 to 16 hours, and 2) an emetic (vomiting) illness with an incubation time of one to six hours.

Symptoms include:

• Abdominal cramps
  Watery diarrhea 
• Nausea
• Vomiting

Onset time:

• Type 1: 6 -15 hours
• Type 2: .5 - 6 hours

Infective Dose:

• Large numbers (more than 105 CFU/gm) of viable Bacillus cereus cells need to be consumed for symptoms of the illness to develop.

Duration of symptoms:

• Usually 1 day

Control:

• Thoroughly cook ground meat products.
• Cool cooked products to 41°F within 4 hours
• Hold hot foods at or above 135 °F.