Impact of wound microbiology on limb preservation in patients with diabetic foot infection

Aims/Introduction:: To investigate the association between specific bacterial pathogens and treatment outcome in patients with limb-threatening diabetic foot infection (LT-DFI). Materials and Methods:: Consecutive patients treated for LT-DFI in a major diabetic foot center in Taiwan were analyzed between the years 2014 and 2017. Patients with positive wound culture results at first aid were enrolled. Clinical factors, laboratory data, and wound culture results were compared. Lower-extremity amputations and in-hospital mortality were defined as a poor outcome. Results:: Among the 558 patients, 272 (48.7%) patients had lower extremity amputation and 22 (3.9%) patients had in-hospital mortality. Gram-negative bacterial (GNB) infection was the independent factor following factors adjustment. When all the 31 microorganisms were analyzed, only E. coli (adjusted odds ratio [aOR], 3.01; 95% CI, 1.60–5.65), Proteus spp. (aOR, 2.99; 95% CI, 1.69–5.29), and Pseudomonas aeruginosa (aOR, 2.00; 95% CI 1.20–3.32) were associated with poor outcome. The analysis of specific GNB species in association with major- or minor- amputation have been reported. No specific pathogen was associated with cause of death in patients with mortality within 30 days. The antimicrobial-resistant strains were not associated with a poor treatment outcome. Conclusions:: The presence of GNB was associated with limb amputations. This study provides insight into more timely and appropriate management of the diabetic foot infection.