Bacterial profile and antimicrobial resistance in diabetic foot ulcer infections: a 10-year retrospective cohort study

Introduction

Diabetic Foot Infections (DFI) are severe complications of diabetes, often resulting in poor clinical outcomes, including amputations. The objective of this study is to identify the main pathogens causing infections in the diabetic foot ulcers, as well as the antibiotic resistance profile.

Methods

This study included all patients treated for diabetic foot infections at a private tertiary hospital between 2013 and 2022. Demographic data, including age, sex, Body Mass Index (BMI), and the level of amputation were extracted from electronic medical records and collected for all patients. Microbiological and resistance patterns were evaluated following standardized protocols. Cases with incomplete demographic or microbiological data were excluded.

Results

This retrospective cohort study analyzed data from 459 diabetic patients, among them, 337 patients with positive cultures were included, resulting in 507 culture results from surgical samples. Gram-negative bacteria accounted for 55.2 % of isolates, with Enterobacterales (41 %) and non-fermenters (14.2 %) being most prevalent. Proteus sp. (10.3 %) and Escherichia coli (8.3 %) were the most common Gram-negative organisms, with significant resistance to ESBL (15.4 %) and quinolones (29.3 %). Among Gram-positive cocci (43.6 %), Staphylococcus aureus (16.8 %) showed 21.1 % methicillin resistance, while Enterococcus sp. exhibited vancomycin resistance (7 %). Multidrug resistance was identified in 16 % of Pseudomonas sp. and 63.6 % of Acinetobacter sp., raising concerns about limited therapeutic options.

Conclusion

The predominance of Gram-negative bacteria and high levels of antimicrobial resistance highlight the need for regular monitoring of local microbiological profiles. Targeted antimicrobial strategies can significantly reduce the morbidity associated with DFI and improve clinical outcomes in diabetic patients.