Postoperative spondylodiscitis caused by Mycobacterium bovis BCG: a case study

BACKGROUND CONTEXT: Postoperative spondylodiscitis (PSD) is a known complication of lumbar disc surgery. The etiology of the disease is usually bacterial, but several uncommon infectious agents have also been described; however, there are no reports about postoperative colonization with Mycobacterium bovis bacille Calmette-Guerin after lumbar discectomy. PURPOSE: To describe the case of PSD caused by M. bovis BCG, and to discuss diagnostic and therapeutic interventions as well as possible pathogenic mechanisms of the disease. STUDY DESIGN: Case report and review of the literature. METHODS: A 31-year-old man was operated on because of L4-L5 lumbar disc herniation. Two months later, the patient presented with gradual increase of back pain, and magnetic resonance imaging confirmed PSD. He started to receive antibacterial treatment and was reoperated on because of progressive neurological deficits due to epidural abscess. Neurological status improved, but a fistula developed with intermittent pus drainage from the operative scar. RESULTS: Microbiological cultures were repeatedly obtained from the pus, but all the initial stains and cultures were negative. Four months after the reoperation, the culture for M. bovis BCG from the pus appeared to be positive. The patient received antituberculosis regimen, including isoniazid, rifampin, ethambutol, and ofloxacin. The clinical symptoms resolved, and antituberculosis treatment was discontinued after 14 months. CONCLUSIONS: Mycobacterium bovis BCG must be considered in the differential diagnosis of PSD. Microbiological analysis and radiological studies are vital components in diagnosis; if there is any suspicion of BCG osteomyelitis, proper diagnostic and therapeutic management must be instituted without delay to avoid an unfavorable outcome. (c) 2012 Elsevier Inc. All rights reserved.