Background: Lumbar intervertebral disc herniation and degenerative disc disease have traditionally been considered consequences of mechanical stress and degenerative changes. This study aimed to evaluate the microbiological profile and antimicrobial resistance patterns of bacteria isolated from extruded lumbar disc specimens obtained from patients undergoing lumbar discectomy.

Methods: In this cross-sectional study, 115 patients undergoing lumbar discectomy were evaluated. Demographic data, clinical characteristics, and MRI findings were recorded. Disc samples were collected intraoperatively under sterile conditions and immediately transported for microbiological analysis. Specimens were homogenized and cultured on blood agar, MacConkey agar, and thioglycollate broth under aerobic and anaerobic conditions at 37°C. Isolated colonies were identified using standard microbiological techniques. Antimicrobial susceptibility testing was conducted according to CLSI guidelines, and multidrug resistance patterns were assessed.

Results: The mean age of patients was 44.7 ± 5.76 years, and 60% were male. Spondylolisthesis (38.3%) was the most frequent MRI finding. Microbiological analysis revealed no bacterial growth in 62.6% of samples. Among positive cultures, anaerobic bacteria (9.5%) were the most common isolates, followed by coagulase-negative staphylococci (6.1%) and diphtheroids (6.1%). Antimicrobial susceptibility testing demonstrated multidrug resistance patterns, particularly among E. coli and P. aeruginosa, with concerning carbapenem resistance observed in Pseudomonas isolates.

Conclusion: The observed antimicrobial resistance patterns highlight potential clinical concerns. These findings support the hypothesis that bacterial involvement may contribute to disc pathology in a subset of patients; however, further large-scale studies using advanced molecular techniques are required to clarify causality.