UNLABELLED: Patients with diabetes mellitus undergo more amputations due to peripheral vascular disease, neuropathy and especially to infection requiring long-lasting antibiotic therapy than non diabetic patients. The aim of our study was to assess the association between the presence of resistant pathogens presented in diabetic ulcers and the frequency of lower limb amputations.

METHODS: 191 diabetic patients consecutively treated for the diabetic foot in our foot clinic were included into two years retrospective study. Peripheral ischemia, the presence of osteomyelitis and the incidence of all Gram positive and negative resistant pathogens (defined as resistance to all oral antibiotics) especially of resistant Staphylococcus species presenting in diabetic foot ulcers were determined.

RESULTS: 50/191 (26%) patients underwent amputation, of whom 44/50 (88%) had minor and 6/50 (12%) had major amputations. 53/181 (29%) patients with diabetic foot ulcers had resistant pathogens in their defects. Amputated patients had significantly more resistant microorganisms than patients without amputations--24/42 (57%) vs. 29/139 (21%); p < 0.001. Resistant Staphylococcus species were found in 21% (38/181) of all patients. Patients with amputations had significantly more resistant Staphylococcus species in comparison with patients without amputations--18/42 (43%) vs. 20/139 (14%); p < 0.001. Significantly higher incidence of peripheral vascular disease--79% (38/48) vs. 60% (81/136); p < 0.05 and osteomyelitis--69% (33/48) vs. 13% (18/140); p < 0.001--were found in patients with amputations in comparison with patients without amputations.

CONCLUSION: The presence of pathogens resistant to all oral antibiotics and especially of resistant Staphylococcus species was significantly higher in diabetic patients with lower limb amputations in comparison with patients without amputations.

Keywords: Amputation; Bacterial Infections /complications/; Diabetic Foot /complications/; Drug Resistance, Microbial; Gram-Negative Bacteria /drug effects/; Gram-Positive Bacteria /drug effects/; Humans; Ischemia /complications/; Leg /blood supply/; Middle Aged; Osteomyelitis /complications/; Retrospective Studies; Risk Factors