Diabetic Foot: Infections and Outcomes in Iranian Admitted Patients

BACKGROUND: Diabetes mellitus (along with its complications) has become a global problem. Diabetic foot infection, among the most common complications, is responsible for 40 to 50% of foot amputations. Antibiotic-resistant microorganisms, however, have compromised empiric therapy in the infected patients. OBJECTIVES: The current study aimed to determine the most common microorganisms involved in diabetic foot infection in order to minimize the failure of antibiotic therapy and the risk of developing complications. PATIENTS AND METHODS: All patients with diabetic foot infection admitted to the infectious diseases, surgery and endocrinology wards of two teaching hospitals from 2007 to 2010 (n = 196) were recruited. In this retrospective study, demographic characteristics, type of lesions, history of hospitalization/antibiotic therapy, isolated microorganisms, clinical complications, administered treatment (medical or surgical) and outcome were recorded. RESULTS: Patients’ mean age was 60.84 (± 10.30) years. Totally, 113 (57.65%) of the patients were male and 83 (42.35%) were female. According to Wagner’s grading, deep ulcers with/without osteomyelitis accounted for the majority of lesions. A single microorganism was isolated (most common: Escherichia coli, Staphylococcus aureus and Klebsiella spp.) from 81 of the patients (80.20%); while for the remaining polymicrobial infection was reported. Isolated pathogens showed no significant correlation with duration of diabetes, type of the lesions (P = 0.13) and history of hospitalization (P = 0.61). The majority of patients (n = 118, 60.20%) were treated surgically; however 11 patients expired due to sepsis. Amputation (most common at toes and below the knee) was performed for 89 patients (45.40%). The response rate to medical treatment was 31.6% for single-pathogen and 10% for polymicrobial infection (with a 30% mortality rate). CONCLUSIONS: Physicians are recommended to take microbiological cultures before starting empirical therapy recommended to cover Gram-negative microorganisms in order to lower the risk of antibiotic resistance.