BACKGROUND: Osteomyelitis (OM) due to carbapenemase-producing Klebsiella pneumoniae (CPKp) is a very rare but severe condition, particularly among patients with hematologic malignancies and stem cell transplant recipients, who are especially at risk of developing nosocomial infections caused by this bacterium.

CASE REPORT: We describe 2 cases of acute and chronic OM by CPKp in adults with hematologic disorders. Patient 1, with acute lymphoblastic leukemia, developed bacteremia due to multidrug CPKp after induction chemotherapy. Despite pathogen-directed antibiotic treatment, blood cultures remained positive for CPKp, with an increase in its resistance pattern, and worsening of clinical condition. A pelvic computed tomography revealed air bubbles in the femoral head and ilium, suggestive of OM, and bone culture was positive for pandrug-resistant CPKp. The clinical condition deteriorated rapidly and the patient died. Patient 2, with aplastic anemia, developed multidrug CPKp bacteremia after immunosuppressive therapy, with good response to pathogen-directed antibiotic treatment. Ten months later, she underwent a hematopoietic stem cell transplant, and at the time of neutrophil engraftment, an abscess developed in the right thigh. An extensively drug-resistant CPKp was isolated from the pus, and antibiotics were started, without clinical improvement. A magnetic resonance of the thigh revealed an intraosseous abscess, suggestive of OM, and after debridement surgery and 6 weeks of parenteral antibiotics, she was successfully discharged home.

CONCLUSIONS: OM due to CPKp is uncommonly reported. These 2 cases illustrate the complex management of OM by CPKp in immunocompromised hematologic patients, and the importance of clinical suspicion for a prompt diagnosis, early treatment, and successful outcome.

Keywords: Hematologic Diseases, Immunocompromised Host, Klebsiella pneumoniae, osteomyelitis, Anemia, Aplastic, Bacterial Proteins, Fatal Outcome, Klebsiella Infections, Precursor Cell Lymphoblastic Leukemia-Lymphoma, transplant recipients, beta-Lactamases