Diagnostic Value of Metagenomic Next-Generation Sequencing for Suspected Native Spinal Brucella Infection: A Multicenter Study

Objective: The aim is to study the diagnostic positive rates of metagenomic next-generation sequencing (mNGS), microbial culture, and serologic testing in suspected native spinal brucellosis, and to evaluate the clinical value of their combined application. Methods: In this multicenter, retrospective observational study, 128 patients with suspected native spinal brucellosis from 6 medical centers (February 2020 to February 2025) were enrolled. Specimens from infection sites were subjected to microbial culture, mNGS, and serological testing (agglutination test). Results: Of the 128 patients with suspected native spinal Brucella infections, 118 patients were diagnosed with Brucella spondylitis. Among the 118 confirmed Brucella spondylitis cases, mNGS demonstrated a positivity rate of 92.37% (109 of 118), significantly higher than that of culture (26.27%, 31 of 118) and agglutination test (83.05%, 98 of 118). In the 87 culture-negative samples, mNGS detected Brucella in 91.95% (80 of 87), compared to 82.76% (72 of 87) by agglutination test. mNGS confirmed Brucella infection in all 16 cases that were agglutination test negative. mNGS combined with agglutination tests can effectively complement each other, improving the sensitivity of diagnosis and thereby minimizing missed diagnoses to the greatest extent. Among the 10 nonbrucellar spinal pathologies, agglutination test showed a high false-positive rate of 90% (9 of 10), whereas mNGS had a 10% (1 of 10) false-positive rate. Therefore, the agglutination test has a relatively high rate of false positives. Conclusion: mNGS detection represents an effective adjunct to microbial culture and the agglutination test. The concurrent use of all 3 methods enhances diagnostic accuracy and reduces the likelihood of missed and incorrect diagnoses, significantly improving patient prognosis and guiding personalized clinical treatment.