Microbiological and Clinical Characteristics of Infected Diabetic Foot Ulcers Managed in a Tertiary Level Diabetic Foot Service

Abstract

The study aimed to evaluate the clinical and microbiological characteristics of diabetic foot infections (DFIs) in patients referring to a specialized diabetic foot service (DFS). The study is a retrospective observational study conducted in a single center, including patients who were referred for a new DFI. All patients were managed through a limb salvage protocol according to international guidelines. The following items were recorded: type of bacteria, presence of single or polymicrobial infection, and the antibiotic resistance. Overall, 268 patients were included. The mean age was 68.9  ±  10.9 years, 75% were male, and 97.2% had type 2 diabetes with a mean diabetes duration of 16  ±  9 years. One hundred thirty-nine (51.9%) DFU were ischemic, 120 (44.7%) patients had osteomyelitis, 107 (39.9%) had gangrene, 37 (13.9%) had phlegmon/abscess/cellulitis and 4 (1.5%) had necrotizing fasciitis. Among 370 bacteria isolated, gram positive were found in 207 (55.9%) cases, and gram negative in 163 (44.1%) cases. The higher rates of isolates were Staphylococcus aureus (32.9%), Pseudomonas aeruginosa (10.8%), and Enterococcus faecalis (8.9%). Polymicrobial infection was reported in 33.6% of cases and antibiotic resistance was recorded in 16.5% of isolates. Among them, 10.3% were methicillin-resistant S. aureus (MRSA). Antibiotic resistance was detected in 40.9% of cases in association with gangrene and osteomyelitis. The current study shows as polymicrobial infections and antibiotic resistance is frequently reported in DFIs, and antibiotic resistance was more associated with gangrene and osteomyelitis. Among bacteria reporting antimicrobial resistance, the highest rate was found for MRSA.