Mycobacterium xenopi related spine infections: A case report and systematic literature review

Nontuberculous mycobacteria (NTM) disease is an important infection disease throughout the world. Mycobacterium xenopi (M. xenopi) is a common NTM. Extrapulmonary infections due to M. xenopi, particularly spine infections, are a rare occurrence, but lack of research is cited as a constraint for implementing NTM control in such patients. The purposes of this paper are to describe a case of spondylodiscitis, to review the published literature on cases of M. xenopi spine infections, and to summarize the predisposing factors, diagnosis, and treatment of infection.

A case of spondylodiscitis was caused by M. xenopi in a patient with systemic lupus erythematosus (SLE). Research was conducted using the PubMed, ScienceDirect, Embase, Wiley Online Library, and Scopus databases using the following search terms: "Mycobacterium xenopi", "vertebral", "spinal", "spondylodiscitis", "infection", and "osteomyelitis".

We retrieved 14 cases published before August 2022. The risk factors for infection were iatrogenic infections (3/14, 21.43%), SLE (4/14, 28.57%), AIDS (4/14, 28.57%), and immunocompetence without any comorbidities (3/14, 21.43%). The most common sites of infection were thoracic vertebrae (10/14, 71.43%) and lumbar vertebrae (4/14, 28.57%). A total of 14 cases were isolated and identified as M. xenopi from a toad by mycobacterial culture. The identification time was 55.00 ± 7.55 days (the present report identification time of metagenomic next generation sequencing (mNGS) was only 2 days). All patients were treated with antibiotic therapy, and the duration of treatment was 13.18 ± 2.13 months. Clarithromycin-based therapy showed a higher improvement rate (5/6, 83.33%). Surgical intervention was performed in 5 patients. Only 1 patient did not show any improvement after surgical treatment.

M. xenopi spine infection in humans presents with atypical clinical symptoms. mNGS identification may be a good choice. M. xenopi may be considered in immunocompromised patients with spinal infection. We recommend a clarithromycin-containing regimen and prolonging the duration of treatment to ensure effectiveness.