Inclusion Criteria:  low back pain lasting longer than 3 months; MRI findings of degenerative lumbar discopathy (DDL) performed less than 6 months after inclusion in the study; indication for open surgical treatment, with isolated microdiscectomy or associated with lumbar arthrodesis; failure of conservative treatment for at least 6 weeks and/or progressive neurological deficit  Exclusion Criteria:  History of open lumbar spine surgery at any stage of life; presence of chemotherapy or pulse therapy with corticoids; patients with immune deficiency; patients undergoing previous intradiscal therapies (nucleotomy or discography); patients undergoing previous endoscopic surgery; patients with a history of previous spinal infection treated with antibiotics in the 6 months prior to inclusion in the study; use of antibiotics in the 2 months prior to the surgical procedure