Bacillus Cereus
المؤلف:
Stefan Riedel, Jeffery A. Hobden, Steve Miller, Stephen A. Morse, Timothy A. Mietzner, Barbara Detrick, Thomas G. Mitchell, Judy A. Sakanari, Peter Hotez, Rojelio Mejia
المصدر:
Jawetz, Melnick, & Adelberg’s Medical Microbiology
الجزء والصفحة:
28e , p186
2025-08-10
574
Food poisoning caused by B. cereus has two distinct forms: the emetic type, which is associated with fried rice, milk, and pasta, and the diarrheal type, which is associated with meat dishes and sauces. B. cereus produces toxins that cause dis ease that is more of intoxication than a food-borne infection. The emetic form is manifested by nausea, vomiting, abdominal cramps, and occasionally diarrhea and is self-limiting, with recovery occurring within 24 hours. It begins 1–5 hours after ingestion of a plasmid-encoded preformed cyclic peptide (emetic toxin) in the contaminated food products. B. cereus is a soil organism that commonly contaminates rice. When large amounts of rice are cooked and allowed to cool slowly, the B. cereus spores germinate, and the vegetative cells produce the toxin during log-phase growth or during sporulation. The diarrheal form has an incubation period of 1–24 hours and is manifested by profuse diarrhea with abdominal pain and cramps; fever and vomiting are uncommon. In this syn drome, ingested spores that develop into vegetative cells of B. cereus secrete one of three possible enterotoxins which induce fluid accumulation and other physiological responses in the small intestine. The presence of B. cereus in a patient’s stool is not sufficient to make a diagnosis of B. cereus disease because the bacteria may be present in normal stool specimens; a concentration of 105 bacteria or more per gram of food is considered diagnostic.
B. cereus is an important cause of eye infections, such as severe keratitis and endophthalmitis. Typically, the organ isms are introduced into the eye by foreign bodies associated with trauma but infections can also occur after surgery. B. cereus has also been associated with localized infections, such as wound infections, and with systemic infections, including endocarditis, catheter-associated bacteremia, central nervous system infections, osteomyelitis, and pneumonia; the presence of a medical device or intravenous drug use predisposes to these infections. Outbreaks of bacteremia in neonatal intensive care units and other hospital units during construction in health care facilities have been reported. B. cereus is resistant to a variety of antimicrobial agents, including penicillins and cephalosporins. Serious non foodborne infections should be treated with vancomycin or clindamycin with or without an aminoglycoside. Ciprofloxacin has been useful for the treatment of wound infections.
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