Bacillus cereus is a spore-forming, facultatively aerobic gram-positive bacilli that is ubiquitously present in nature and can cross-contaminate food and medical equipment. This bacteria is mostly known as the etiologic agent of two distinct clinical food poisoning syndromes (an emetic syndrome and a diarrheal syndrome). However, in recent years, it has been increasingly recognized as the etiologic agent of serious and potentially fatal infections in both immunocompetent and immunocompromised patients.

The pathogenicity of B. cereus is related to its ability to form biofilms and spores that confer resistance against standard cleaning procedures, as well as the production of a variety of tissue-destructive enzymes and toxins.

The foodborne disease caused by B. cereus does not show a predilection for a particular population group. Nongastrointestinal disease is most commonly reported among neonates, intravenous drug abusers, patients sustaining traumatic or surgical wounds, and those with indwelling catheters.

Less frequently, B. cereus can cause bloodstream and catheter-related infections, respiratory infections, severe invasive central nervous system (CNS) disease (meningitis and brain abscesses in immunosuppressed patients with hematological malignancies), endophthalmitis, and gas gangrene-like infections.