Retrospective study on the distribution of pathogens, antibiotic resistance patterns, and risk factors of multidrug-resistant organism infections in patients with type 2 diabetic foot ulcers.

Multidrug-resistant organism (MDRO) infections are increasingly prevalent in patients with type 2 diabetic foot ulcers (DFUs), posing substantial challenges to treatment efficacy and clinical outcomes. Understanding the risk factors and epidemiological characteristics of MDRO infections is critical for formulating effective antimicrobial strategies. This single-center retrospective study included 247 patients hospitalized with DFUs between January 2022 and December 2024. Based on microbiological findings, patients were classified into an MDRO group (n = 102) and a non-MDRO group (n = 145). Data on demographics, pathogen distribution, antibiotic resistance profiles, and clinical outcomes were collected. Logistic regression analysis was performed to identify independent risk factors for MDRO infection, and clinical outcomes were compared between the 2 groups. Patients in the MDRO group had a longer duration of diabetes and higher HbA1c levels, along with a significantly greater proportion of Wagner grade ≥ 3 ulcers and peripheral arterial disease (all P < .05). A total of 268 pathogenic strains were isolated, predominantly Gram-negative bacteria (62.3%), with Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii being the most common. The leading MDROs were extended-spectrum β-lactamase-producing E. coli (14.6%) and carbapenem-resistant A. baumannii (11.2%). Multivariate analysis identified Wagner grade ≥ 3 (odds ratio [OR] = 2.31), prior use of broad-spectrum antibiotics (OR = 2.87), and peripheral arterial disease (OR = 1.96) as independent risk factors for MDRO infection. Compared with the non-MDRO group, the MDRO group had significantly higher rates of treatment failure (34.3% vs 18.6%), readmission (21.6% vs 10.2%), and greater antibiotic use, both in number and duration (all P < .05). Higher Wagner grades were also associated with increased rates of MDRO and mixed infections (P < .001). MDRO infections are common among patients with DFUs, with Gram-negative bacteria as the predominant pathogens. Higher Wagner grade, prior antibiotic exposure, and peripheral arterial disease are independent risk factors. MDRO infections impose a greater treatment burden and are linked to poorer prognoses. Early identification of high-risk patients, coupled with optimized infection control and antimicrobial stewardship, is essential to improving clinical outcomes.