Vertebral osteomyelitis caused by nontuberculous mycobacteria: a case series of 23 patients and a review of 108 cases in the literature.

backgroundNontuberculous mycobacteria (NTM) are ubiquitous environmental opportunistic pathogens that rarely cause spinal infections. The clinical presentation, diagnostic process, and treatment strategies for NTM vertebral osteomyelitis often resemble those of spinal tuberculosis, posing significant challenges to clinical management.

objectiveThis study aims to systematically analyze the clinical characteristics, imaging findings, microbial profiles, treatment approaches, and outcomes of NTM vertebral osteomyelitis, with a comparative review of relevant global literature to further elucidate their features.

methodsWe retrospectively analyzed 23 cases of NTM vertebral osteomyelitis diagnosed at our institution from 2021 to 2025. Inclusion criteria included spinal lesions with local and/or systemic symptoms, confirmed by positive NTM culture and/or molecular testing of biopsy or aspirate samples. Exclusion criteria were: (1) infections confirmed to be caused by Mycobacterium tuberculosis or other non-NTM pathogens, or cases with incomplete data; (2) patients with severe heart, liver, kidney dysfunction, or psychiatric disorders. Data collected included demographics, medical history, clinical presentation, imaging and laboratory findings (e.g., white blood cell count, C-reactive protein, erythrocyte sedimentation rate), microbiological profiles, and treatment outcomes. A literature review was conducted using PubMed, Google Scholar, and MEDLINE to retrieve studies on NTM spinal infections from 1970 to 2025 for comparative analysis.

resultsThe study included 23 patients, with 43.5% (10/23) male and 56.5% (13/23) female, aged 38–80 years (mean: 57.35 ± 13.5 years). Predisposing factors included long-term glucocorticoid use (7/23), prior surgery (7/23), diabetes (7/23), and Human Immunodeficiency Virus (HIV) infection (2/23). All patients (100%, 23/23) presented with progressive spinal pain and restricted mobility, with fever in 5/23 (21.7%). Imaging revealed vertebral destruction in 87.0% (20/23) and intervertebral disc involvement in 52.2% (12/23). Microbiologically, Mycobacterium avium complex (MAC) was the most common pathogen (73.9%, 17/23), followed by Mycobacterium abscessus (M. abscessus) (13.0%, 3/23), with one case each of Mycobacterium iranicum (M.iranicum), Mycobacterium genavense (M. genavense), and Mycobacterium gordonae (M. gordonae). All patients received antibiotic therapy, with 78.3% (18/23) undergoing surgical intervention. After a mean follow-up of 18 ± 3.7 months (range, 12–24 months),13 patients showed complete or marked clinical improvement, Outcome data were not available for one patient who abandoned treatment. The literature review identified 92 studies reporting 108 NTM vertebral osteomyelitis cases.

conclusionNTM vertebral osteomyelitis is rare and diagnostically challenging due to their similarity to spinal tuberculosis. Early microbial identification is critical for individualized treatment. This case series of 23 patients significantly enriches the literature on NTM spinal infections, providing valuable clinical insights. Larger studies are needed to further characterize NTM infections.