[Diabetic foot infections: microbiological aspects]

The diagnosis of wound infection is based on clinical signs and local and/or systemic inflammation. Therefore, the examination has a major role in the diagnosis of infected lesions of the foot. Once the clinical diagnosis of infection is made, the next step is to determine the etiology with the aim to undertake a rational and appropriate treatment. The most reliable method for assessing microbiological etiology is the specimen of material from infected lesion to perform a bacterioscopic examination and culture. The microorganisms involved in the etiology of diabetic foot depends on the type of injury and on specific patient features (antibiotic therapy, previous hospitalization). The most frequently detected pathogen is Staphylococcus aureus. Mild infections are mostly caused by Gram positive cocci, with a prevalence of S. aureus. Moderate infections are mostly supported by pyogenic Gram positive cocci, but also Gram-negative bacteria can be involved. In severe infections the etiology is polymicrobial. As regards the involvement of fungi in diabetic foot infections data are few and mostly conflicting.