Characterization of bacterial isolates from diabetic foot infections in Ile-Ife, Southwestern Nigeria

Background: The characterization of bacterial agents cultured from diabetic foot infections was prospectively undertaken in Ile-Ife, Nigeria. Objectives: Characterization of bacterial agents involved in diabetic foot infections, and ways of reducing long period of hospitalization. Methods: Diabetic patients with foot infections were selected on volunteer basis. Superficial swab and deep tissue biopsies were inoculated into freshly prepared thioglycolate broth medium. Bacterial agents were identified by conventional bacteriologic methods. Four different enzymes, namely protease, DNAase and RNAase and lipase were assayed. Sensitivity tests were performed according to method of [Bauer AW, Kirby WWM, Sherris JC, Turck M. Antibiotic Susceptibility testing by a standardized single disk method. Am J Clin Pathol, 1966; 45: 493-495]. Results: Aerobes constituted 90.7% of bacterial isolates of which Gram-negative rods accounted for 57.9%. Escherichia coli was the single most predominant organism (15.1%). Aerobic Gram-positive bacteria accounted for 32.8%. Staphylococcus aureus predominated (13.2%) followed by CONS (9.2%) Streptococcus spp. and Corynebacterium spp. 5.2% each. Proteus species contributed (32.9%) of Gram-negative aerobes and Pseudomonas aeruginosa (12.5%). Eight (8.3%) of the Gram-negative rods were anaerobes. Conclusion: The study highlighted prevalence of multiple antibiotic resistant bacteria in foot infections, and recommends culture-guided therapy to reduce the incidence of antibiotic resistance. It also suggests that superficial swab samples could be as useful as deep tissue biopsies in enumerating fastidious bacterial species in diabetic ulcers if properly carried out. © 2006 Elsevier Ltd. All rights reserved.