Osteomyelitis due to Clostridium innocuum in a patient with acute lymphoblastic leukemia: case report and literature review

Introduction: Clostridium innocuum is an anaerobic Gram-positive bacterium, unable to produce toxins and rarely causes infections. We report the first case of C. innocuum osteomyelitis and bacteremia in a patient with acute lymphoblastic leukemia ( ALL). Findings were compared with previously reported cases of C. innocuum infections in immunocompromised patients, e.g., patients with acquired immune deficiency syndrome, leukemia, and organ transplantation. Case description: A 32-year-old Japanese male was admitted for persistent low-grade fever and purpura lasting for 1 month. Complete blood counts and cytogenetic analysis identified Ph1-positive ALL, which was successfully treated using chemotherapy. However, the patient developed high fever and lumbar pain during complete remission. Fluorodeoxyglucose-positron emission tomography and computed tomography demonstrated osteomyelitis. C. innocuum was identified as the causative agent and the patient was successfully treated using antibiotic therapy. Discussion and evaluation: We performed a literature review revealing a number of common aspects to the clinical presentation of C. innocuum infection and an association with various comorbidities. Further, we highlight the most efficient diagnostic and treatment strategies for C. innocuum osteomyelitis. Conclusions: Clostridium innocuum can be a causative pathogen of osteomyelitis and bacteremia in immunocompromised patients.