Successful preemptive therapy for cerebral multiple hemorrhagic infarctions due to septic embolism by Bacillus cereus after allogeneic hematopoietic stem cell transplantation for acute myelogenous leukemia

Abstract

A 58-year-old man was diagnosed with acute megakaryocytic leukemia and subsequently underwent reduced intensity allogeneic stem cell transplantation from his sibling donor. On day 6 after the transplantation, he developed febrile neutropenia, and intravenous doripenem was started. Since gram-positive rods were isolated from blood cultures, and because Bacillus cereus (B. cereus) was suspected, vancomycin therapy was added. On day 8, he developed a decreased level of consciousness and left hemiplegia. Magnetic resonance imaging of the brain revealed meningitis, multiple brain hemorrhages, and subdural hemorrhage. Bacteria from blood cultures were identified as B. cereus, and we considered that those brain lesions were caused by inflammation and septic embolism by B. cereus. On day 8, antibiotic therapy was changed to levofloxacin and imipenem/cilastatin, according to the result of antimicrobial susceptibility testing, and sepsis resolved; however, hemiplegia persisted. Since B. cereus sepsis is associated with an aggressive clinical course, especially in the context of neutropenia, effective treatment for B. cereus should be started as soon as grampositive rod bacteremia is identified.