Fatal Bacillus cereus meningoencephalitis in an adult with acute myelogenous leukemia.

Bacillus cereus, a ubiquitous, endospore-forming, aerobic gram-positive bacillus, is primarily associated with toxin-mediated food poisoning. Frequently, isolates of Bacillus species from clinical specimens are discussed as contaminants. We report a rapidly fatal case of disseminated infection due to B cereus in a patient receiving induction chemotherapy for M0 acute leukemia. A short clinical syndrome of nausea and vomiting preceded neurologic symptoms. Autopsy showed extensive meningoencephalitis with subarachnoid hemorrhage and multiple liver abscesses. Areas of necrosis were devoid of any inflammatory response consistent with a severely immunocompromised state. The organism was isolated from immediate premortem and autopsy blood specimens. This case illustrates the possibility and severity of true B cereus infections in immunocompromised patients, the clinicopathologic features of which are as yet not well defined.