Vertebral osteomyelitis associated with Granulicatella adiacens

Granulicatella adiacens is a nutritionally variant streptococci. Only 3 cases of vertebral osteomyelitis due to these microorganisms have been reported. We experienced a 73-year-old male who consulted us due to fever and back pain of about 1-month duration. On examination, a presystolic murmur was heard in the apical region. Echocardiography showed prolapse of the mitral valve, but no vegetation was observed. MRI revealed osteomyelitis of lumbar vertebrae. As G. adiacens was detected in blood culture, it was determined as the cause of vertebral osteomyelitis, and combination antibiotics therapy was started. The condition improved, the patient underwent valvoplasty, and no trace of infective endocarditis was noted in the resected valve. All the previous cases had infection caused by G. adiacens and complicated with infective endocarditis. This is the first case without infective endocarditis. Vertebral osteomyelitis due to NVS is very rare. Since nutritionally variant streptococci do not grow in common culture media, and since the sensitivity of isolation by standard conventional biochemical methods is low, the condition may be misdiagnosed as blood-culture-negative vertebral osteomyelitis. Therefore, the possibility of nutritionally variant streptococci infection should be considered if a patient with vertebral osteomyelitis shows a positive Gram stain but negative blood cultures.