Microbial Isolates in Diabetic Foot Lesions of Hospitalized Patients at the University Hospital of the West Indies

Abstract

Background: The diabetic foot is a frequent complication of diabetes mellitus. It confers a negative impact on the patients' quality of life and profound burden on the healthcare system. The objectives were to determine: 1. The bacteriological profile and antibiotic susceptibility of patients admitted to the University Hospital of the West Indies with diabetic foot ulcer over a five year period. 2. Whether methicillin-resistant Staphylococcus aureus is a common microbial isolate and if antibiotic resistance played a role on duration of hospital stay or amputation Methods: A retrospective analysis was done on patients admitted from January 2003 to December 2008 with the diagnosis of diabetic foot. Patients' records were located from the Medical Records' department. Demographic data, types of cultures done and results, antibiotic susceptibility and resistance, and treatment regimens were all recorded. Frequency means were calculated and statistically significant covariates used as predictors in univariate and multivariate regression models. Results: Of 545 cases admitted, 102 had complete data for analysis. Group D Streptococci was the most common organism isolated (45.1%) followed by other forms of Streptococci and Pseudomonas aeruginosa. The majority of cases (80.6%) had two or more bacterial isolates. Gram-negative bacteria (Proteus and Klebsiella) and anaerobes were also common, 48.0% and 22.5% respectively. There were no cases of methicillin-resistant Staphylococcus aureus. Antibiotic resistance was not significant. Conclusions: Gram-positive organisms specifically the Streptococci species remain an important organism in diabetic foot infections. Current empiric antibiotic regimes used are effective in this referral university hospital.