Risk factors and clinical outcomes of multidrug-resistant and biofilm-producing infections in diabetic foot ulcers: a two-year cohort study.

Abstract

This two-year prospective study analysed 124 diabetic foot ulcer (DFU) patients admitted to the Department of Surgery to identify clinical and microbiological predictors of multidrug-resistant (MDR) and biofilm-producing infections. The cohort was predominantly male (82.3%), with a mean age of 54.3 ± 11.6 years and a high prevalence of tobacco use (63%) and illiteracy (48.4%). Most patients (91.1%) exhibited poor glycaemic control (mean HbA1c 8.3 ± 1.3%), with neuropathy (79%) and retinopathy (72.6%) as the most common comorbidities. Ulcer severity ranged from Wagner grade 1 to 4, with 60.5% persisting for over one month. Microbiological analysis revealed 59.7% monomicrobial and 33.9% polymicrobial infections, with biofilm formation detected in 60.5% of isolates. Multivariable logistic regression showed significant associations between MDR isolates and tobacco use (OR: 4.06, P = 0.049), polymicrobial infections (OR: 20.75, P < 0.001), and biofilm formation (OR: 3.84, P = 0.033). Predictors of biofilm production included male sex (OR: 7.89, P = 0.023), neuropathy (OR: 4.44, P = 0.040), prolonged ulcer duration (OR: 0.09, P = 0.001), non-necrotic ulcers (OR: 0.16, P = 0.014), and MDR organisms (OR: 3.64, P = 0.034). Clinical outcomes included a 30.6% amputation rate (22.6% minor, 8.1% major) and an 8.9% mortality rate, with a mean hospital stay of 22.9 ± 9.2 days. These findings highlight the multifactorial nature of MDR development and biofilm-associated infections, emphasizing the critical roles of biofilm formation, polymicrobial infections, and tobacco use in DFU management. Early intervention and tailored therapies are essential to mitigate these risks and improve patient outcomes.