The presence of S aureus in the nasal passages of diabetic patients may be a risk factor for diabetic foot lesion infections. Our aim is to compare the genetic profiles of S aureus strains found in the noses and on the foot lesions of diabetic patients. The investigators are also studying the virulence of these strains, the prevalance of S aureus at either site, and whether or not the quantity of S aureus found in the nose affects the risk for infection in foot lesions. The investigators also use this study to test the sensitivity and specificity of the GeneXpert system.