Methicillin-resistant Staphylococcus aureus: an increasing problem in a diabetic foot clinic

Aim To study the prevalence of pathogenic organisms and the prevalence and outcome of methicillin-resistant Staphylococcus aureus (MRSA) infection in foot ulcers in diabetic patients. Methods A retrospective analysis of wound swabs taken from infected foot ul cers in diabetic patients, selected from an outpatient diabetic foot clinic . Seventy-five patients (79 ulcers) with positive wound swabs were included . Size of ulcer and time to healing, in particular for MRSA-infected ulcers , were measured in all patients. Results Gram-positive aerobic bacteria were the commonest micro-organism is olated (56.7%) followed by Gram-negative aerobic bacteria and anaerobes (29 .8% and 13.5%, respectively). Of the Gram-positive aerobes, S. aureus was f ound most frequently and 40% were MRSA. MRSA was isolated more commonly in patients treated with antibiotics prior to the swab compared to those who h ad not received antibiotics (P=0.01). Patients whose foot ulcers were infec ted by MRSA had longer healing time than patients whose ulcers were infecte d by methicillin-sensitive S. aureus (mean (range) 35.4 (19-64) and 17.8 (8 -24) weeks, respectively, P=0.03). Conclusion MRSA infection is common in diabetic foot ulcers and is associat ed with previous antibiotic treatment and prolonged time to healing. Furthe r studies are required to assess the need for antibiotics in treating foot ulcers in diabetes and to assess the optimum therapeutic approach to this p roblem.