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Bacillus cereus Biological Agent Reference Sheet (BARS)

Updated October 2, 2023
Disclaimer: Risk group, biosafety level, and all other precautions noted here are subject to change after a risk assessment by EHS.


Agent Type Risk Group Biosafety Level Animal Housing Biosafety Level
Bacteria  RG-2 BSL-2 ABSL-2

Agent Characteristics 

Risk Group:  RG-2 associated with human disease, rarely serious; preventive or therapeutic interventions often available.

Agent Type:  Bacteria 

Description: Bacillus cereus is a Gram-positive, facultative, aerobic, spore-forming bacteria. Unlike related members of the Bacillus genus, this bacterium can also be characterized by its motility, beta hemolytic potential, and (for Bacillus cereus var mycoides) rhizoidal growth. Bacillus cereus can be on occasion mistaken for other pathogenic members of the genus such as B. thuringiensis and B. anthracis. Bacillus cereus causes complications through a variety of enterotoxins. These result in the intoxication stage of the disease, characterized by either diarrhea or emetic illness (nausea, abdominal pain, and vomiting). B. cereus illness can also develop into the more severe infectious stage, manifesting itself as cutaneous infection, septicemia, gastritis, among others. The enterotoxins are known to cause severe disruption of the epithelial lining of the small intestine and lysis of erythrocytes. These are the primary causes of the intoxication stage of the disease.

Host Range: Animals and humans, especially those who are immunocompromised, intravenous drug users, or neonates.

Host Shedding: Blood, Direct contact, Feces                  Route of Exposure to Humans: Direct Contact

Infectious Dose: The toxin responsible for diarrheal illness is produced by organisms in the small intestine; infectious dose is 104 to 109 cells per gram of food.        

Incubation Period: The diarrheal form of B cereus has an onset period of 8-16 hours while the emetic form has an onset period of 1-6 hours. Recovery is usually complete in 24 hours

Health Hazards

Signs and symptoms of infection may include:

  • Cutaneous symptoms (i.e. skin lesions, rash)

  • Gastrointestinal symptoms (i.e. loss of appetite, nausea, vomiting, diarrhea)
  • Respiratory symptoms (i.e. coughing, sneezing)
  • Lymphoreticular symptoms (i.e. enlarged internal organs or lymph nodes)

Immunizations: None available                            Prophylaxis*: Food Safety Information

*Formal medical advice is obtained during medical consultations with Cornell Health or a primary healthcare provider as needed.

Agent Viability 

Survival Outside Host Disinfection Inactivation

Survives in soil and on vegetation; generally heat resistant, and thus may survive thermal food processing with or without injury to cells. 

1:10 Bleach Dilution 

Peracetic acid, activated hydrogen peroxide, chlorine dioxide, formaldehyde, iodine, acids, alkali; pulse electric field in 0.15 % sodium chloride solution 

Spores can be resistant to heat and radiation, but heating at 100°C for 5 minutes results in cellular damage to the membranes and ribosomes; gamma irradiation at 2-5 kGy.

Autoclave at least 1 hour at 121°C, 15 psi.

For more guidance on disinfection see: disinfectant selection.

Laboratory Hazards 

  • High energy-creating activities (centrifugation, sonication, high pressure systems, vortexing, tube cap popping)

  • Handling of sharps (needles, scalpels, microtome blades, broken glass, etc.)

  • Splash/droplet-creating activities (shaking incubators, liquid culturing, mechanical pipetting)

  • Equipment contamination

  • Exposed skin/uncovered wounds

Laboratory Acquired Infection (LAI) History: None reported to date.

Laboratory Handling Guidelines 

Laboratory Biosafety Level (BSL): BSL-2


Lab Engineering Controls Personal Protective Equipment
  • Eye Protection
  • Single gloves
  • Additional gloves
  • Snap-front lab coat with cinch cuffs

Waste Management: Regulated Medical Waste (RMW)

Shipping Guidance: Refer to EHS Biological Materials Shipping 

Animal Vivarium Guidance

Animal Housing Biosafety Level (ABSL): ABSL-2

Animal Biosecurity:  Experimental animals are housed separately.      

To determine where inoculations and cage changes should be performed, please contact EHS Biosafety.

Exposure and Spill Procedures 

Mucous Membranes: Flush eyes, mouth, or nose for 15 minutes at an eyewash station. See: responding to exposures.

Other Exposures: Wash with soap and water for 15 minutes (open wounds, sores, etc.) or a minimum of 20 seconds for areas with intact skin. See: responding to exposures.

Small Spills: Notify others working in the lab. Evacuate area and allow 30 minutes for aerosols to settle. Don appropriate PPE. Cover area of the spill with paper towels and apply disinfectant, working from the perimeter toward the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials. See: spill cleanup.

Large Spills: Request assistance from the EHS Spill Team by calling CUPD dispatch. Call 911 from a campus phone or 607-255-1111 from a mobile phone.

Incident Reporting: Immediately report the incident to supervisor and complete the EHS online injury/illness report as soon as possible.

Medical Follow-Up:

  • For students, seek medical attention at Cornell Health or local primary care provider. Call Cornell Health at 607-255-5155 (24-hour phone consultation line) or a local urgent care. 
  • For faculty and staff, seek medical evaluation with a local primary care provider or urgent care. Cornell Health does not see employees for post-exposure care. 
  • Emergencies: Call 911 from a campus phone or 607-255-1111 from a mobile phone. 

Cornell EHS would like to thank Emory University for the use of their Biological Agent Reference Sheet (BARS) format and some content. 

More Information


  1. Bacillus cereus Pathogen Safety Data Sheet. Public Health Agency of Canada.

  2. BBB – Bacillus cereus and other Bacillus spp. Bad Bug Book. U.S. Food & Drug Administration.

  3. Warth AD. Relationship between the heat resistance of spores and the optimum and maximum growth temperatures of Bacillus species. Journal of Bacteriology. 1978;134(3):699-705. 

  4. Senesi S, Ghelardi E. Production, Secretion and Biological Activity of Bacillus cereus Enterotoxins. Toxins. 2010;2(7):1690-1703. doi: 10.3390/toxins2071690

  5. Bacillus cereus. Food Standards Australia New Zealand