A 38-year-old man from rural Maharashtra presents with a 4-month history of progressive back pain, low-grade fever, and weight loss. On examination, he has kyphotic deformity at the thoracic spine and mild paraparesis. MRI shows destruction of T5–T6 vertebral bodies with retropulsed disc material and epidural abscess causing cord compression. ESR is 78 mm/hr and sputum smear microscopy is negative. What is the most appropriate next step in management?