Bacteriologic study of diabetic foot ulcer

Objective: To study the relative frequency of bacterial. isolates cultured from diabetic foot infections and assess their in vitro susceptibility to the commonly used antibacterial agents. Methodology: In total 32 hospitalized diabetic patients with foot infections were investigated. Deep tissue biopsies were inoculated into freshly prepared Thioglycollate broth medium. Bacterial agents were identified by conventional bacteriologic methods. Sensitivity tests were performed according to standard disc diffusion method of Kirby & Bauer. Results: Clinical grading and bacteriological study of 32 patients with diabetic foot lesions revealed polymicrobial etiology in 16 (50%) and single etiology in 10 (31.2%) and six negative cultures. Aerobic Gram-positive bacteria accounted for 42.9%. Staphylococcus aureus was the most frequent microorganism yielded (26.2%), and Staphylococcus epidermidis was regularly associated with the lesions (14.3%). Gram-negative rods accounted for 54.8%. Escherichia coli was the most predominant gram negative organism (23.8%). No anaerobes were isolated from the ulcers. All the microorganisms isolated showed high resistance to used antibiotics, amongst them, Staphylococcus aureus and Pseudomonas aeruginosa were the most resistant bacteria in present study. Conclusion: Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis and Proteus vulgaris were the most common causes of diabetic foot infections in present study. And the rate of antibiotic resistance was 65% among the isolates. Due to polymicrobial infection and antibiotic resistance, surgical intervention must be concerned.