Microbiological Signatures and Clinical Predictors of Severity in Diabetic Foot Infection

<p><strong>Introduction:</strong> Diabetic foot infection (DFI) is a major complication of diabetes associated with high rates of amputation, recurrence, and healthcare utilization. The prognostic interaction between clinical and microbiological markers remains unclear.</p><p><strong>Aim:</strong> The present analysis aimed to characterize clinical, inflammatory, and microbiological predictors of course and resource use in surgically managed DFI.</p><p><strong>Material and methods:</strong> We retrospectively analyzed 121 hospitalizations of 86 patients treated surgically for DFI (2021-2025). Clinical, laboratory, and microbiological variables were assessed in relation to amputation, reamputation, rehospitalization, length of stay (LOS), and mortality.</p><p><strong>Results:</strong> Amputation was performed in 72/121 episodes (59.5%), including 57 minor and 15 major procedures. Reamputation occurred in 13/72 cases (18.1%). Rehospitalization was recorded in 42/86 patients (48.8%). Median LOS was 13 days (IQR 8-21). A total of 227 isolates were obtained, with <em>Enterococcus faecalis</em> (38 isolates, 16.7%) and <em>Staphylococcus aureus</em> (28 isolates, 12.3%) being the most frequent. Polymicrobial infections were present in 75/121 episodes (63%). Neuro-ischemic ulcer phenotype independently predicted reamputation (aOR 3.72; p = 0.036). <em>Staphylococcaceae</em> increased the likelihood of rehospitalization (aOR 3.32; p = 0.014). NLR &gt;5 prolonged LOS by 42%, and <em>Enterococcus</em> spp. by 51%. Repeat hospitalizations showed enrichment of ESBL <em>Klebsiella pneumoniae</em> (5 cases) and HLAR E. faecalis (9 cases).</p><p><strong>Conclusions: </strong>Ulcer phenotype and systemic inflammatory response were the strongest predictors of adverse outcomes. Microbiology contributed selective yet clinically meaningful prognostic information, particularly regarding <em>Staphylococcaceae</em> and <em>Enterococcus</em> spp.</p>.