Risk Factors for Infection with Pseudomonas aeruginosa in Diabetic Foot Infections

Selecting empirical therapy for a diabetic foot infection (DFI) requires knowing how likely infection with Pseudomonas aeruginosa is in a particular patient. We designed this study to define the risk factors associated with P aeruginosa in DFI.

We performed a preplanned microbiological subanalysis of data from a study assessing the effects of treatment with intralesional epidermal growth factor for diabetic foot wounds in patients in Turkey between January 1, 2012, and December 31, 2013. Patients were screened for risk factors, and the data of enrolled individuals were recorded in custom-designed patient data forms. Factors affecting P aeruginosa isolation were evaluated by univariate and multivariate logistic regression analyses, with statistical significance set at P < .05.

There were 174 patients enrolled in the main study. Statistical analysis was performed in 90 evaluable patients for whom we had microbiological assessments. Cultures were sterile in 19 patients, and 89 bacterial isolates were found in the other 71. The most frequently isolated bacteria were P aeruginosa (n = 23, 25.8%) and Staphylococcus aureus (n = 12, 13.5%). Previous lower-extremity amputation and a history of using active wound dressings were the only statistically significant independent risk factors for the isolation of P aeruginosa in these DFIs.

This retrospective study provides some information on risk factors for infection with this difficult pathogen in patients with DFI. We need prospective studies in various parts of the world to better define this issue.