Causes of Bacterial Infections and Antibiotic Resistance Profiles in Patients with Chronic Wounds

This retrospective, descriptive study examined the microbial distribution and antibiotic resistance profiles of predominant pathogens in chronic wounds among patients presenting to a regional hospital's chronic wound outpatient clinic between July and November 2025, with the aim of informing empirical antibiotic therapy and regional antibiotic stewardship programs. Among the 105 patients included (mean age 62.69 ± 17.14 years, 60% male), diabetic foot ulcer was the most common wound type (49.5%). Of the isolates obtained, 70.2% (n = 73) were Gram-negative and 29.8% (n = 31) were Gram-positive microorganisms, with Escherichia coli and Pseudomonas aeruginosa being the most frequently isolated pathogens (16.3% each), followed by Staphylococcus aureus (15.4%). S. aureus predominated in diabetic foot ulcers, whereas P. aeruginosa predominated in peripheral artery disease, though no statistically significant association was found between wound type and bacterial group (p = 0.055). A multidrug-resistant phenotype was detected in 16.3% (17/104) of isolates. No significant differences emerged between Gram-negative and Gram-positive groups regarding HbA1c, WBC, and CRP levels (p > 0.05), although WBC and CRP showed a moderate positive correlation (ρ = 0.396, p < 0.001). These findings highlight the predominance of Gram-negative microorganisms and considerable antibiotic resistance in chronic wound infections, emphasizing that culture-based diagnosis remains essential since laboratory parameters cannot reliably predict the causative microbial group, and that empirical therapy should be guided by local resistance patterns.