Three cases of vertebral osteomyelitis caused by Streptococcus dysgalactiae subsp. equisimilis.

Three cases of vertebral osteomyelitis caused by Streptococcus dysgalactiae subsp. equisimilis (Strep. equisimilis) are presented here. All three cases presented with fever, back pain, general malaise and weight loss for at least 4 weeks. Diagnosis was established by culture of a spinal biopsy and/or positive blood cultures together with radiological findings. In all three cases, 6-12 weeks of antibiotics were curative without recourse to surgery. The ability of Strep. equisimilis to cause vertebral osteomyelitis is highlighted. The need is emphasized for biopsy and microbiological investigation in patients presenting with back pain, fever, weight loss and evidence of a spinal lesion on imaging, even if neoplastic disease is suspected. Prolonged antibiotic therapy (at least 6 weeks) seems to be indicated.