Diabetic Foot Infection: Exploratory Analysis of Its Clinical Profile, Microbiology, and Outcomes

Diabetic foot infections (DFI) lead to severe complications, including amputation and hospitalizations. Despite frequent antibiotic use, local microbiological data remain scarce in Chile.

To assess the microbiological profile, resistance patterns, and clinical outcomes of DFI patients in a single Center in Chile.

A retrospective analytical study was conducted on hospitalized adult with DFI who underwent surgical debridement or amputation with positive intraoperative cultures between 2017 and 2022. Data were collected from medical records.

Among 516 patients, 272 had positive intraoperative cultures, with 126 randomly selected for analysis. Mean age was 61.8 years. Most presented with localized infections and Wagner stage ≥3. Patients presented with localized infections, with minimal inflammatory or systemic repercussion. Only one patient required ICU admission. Microbiological analysis revealed Gram-positive cocci (GPC; 93.4%) predominating in patients without prior amputation, whereas Gram-negative bacilli (GNB; 52%) were significantly higher in those with prior amputations (p= 0.03). For previously amputated patients, higher resistance values for third-generation cephalosporins (OR 17.6), piperacillin-tazobactam (OR 8.8), and sulbactam-ampicillin (OR 6) were detected. 85.7% of patients underwent amputations and median hospital stay was 14 days. Within the first year, 54% (n= 68) of patients required at least one rehospitalization. Patients were followed for a median of 33 months and during this period, 47 patients (37.3%) died. Only 5 out of 47 deaths (10.6%) were directly or indirectly caused by DFI. Multivariate logistic regression analysis found amaurosis, heart failure, and age as independent mortality predictors. Median overall survival was 60 months. Microbiological follow-up in new admissions, indicated an increasing proportion of GNB with a higher proportion of antimicrobial resistance to first- or second-line compounds.

DFI in Chile exhibits high morbidity, recurrent hospitalizations and progressive antibiotic resistance. Mortality is not significantly associated to infection but to other factors linked to DM.