SLR - August 2021 - Howard C. Chang

The Influence of Multidrug-Resistant Bacteria on Clinical Outcomes of Diabetic Foot Ulcers: A Systematic Review  

References: Matta-Gutiérrez G, García-Morales E, García-Álvarez Y, Álvaro-Afonso FJ, Molines-Barroso RJ, Lázaro-Martínez JL. The Influence of Multidrug-Resistant Bacteria on Clinical Outcomes of Diabetic Foot Ulcers: A Systematic Review. Journal of clinical medicine 2021;10(9):1948.

Level of Evidence: Level I, Systematic Review 

Scientific Literature Review 

Reviewed By: Howard C. Chang, DPM
Residency Program: Regions/HealthPartners Institute – St. Paul, MN 

Podiatric Relevance: Multidrug-resistant organism (MDRO) infections negatively affect the clinical outcomes of any infections including that of diabetic foot ulcers. The study aims to review and evaluate various clinical outcomes including ulcer duration, healing time, hospital stay, amputation and mortality rates in patients with diabetic foot ulcers and concomitant multidrug-resistant organism. 

Methods: Systematic literature review using PRISMA guidelines. Literature search was performed using three databases (PubMed, Cochrane Library, and Web of Science). Keywords used include (‘multidrug resistant’ OR ‘multi-drug resistant’ OR ‘multidrug-resistance’) AND (diabetic foot). Inclusion criteria includes (1) observational study, case-control, and cohort studies in adult patients (2) DFU with multi-drug organism infection, (3) mean ulcer duration and the healing time of ulcers, and (4) evaluation of clinical outcomes related to infection. Exclusion criteria (1) RCT, (2) alternative treatments, (3) no data available for analysis, (4) non-original articles. Two hundred seventeen articles were identified, eight were selected for final analysis. 

Results: The authors found no association between duration of ulcer and the presence of MDRO. In the systematic review, the time to healing was prolonged in patients found to have MDRO compared to a non-MDRO infection. Hospitalization period was found to be significantly increased in two studies. Patients with MDRO infections required higher rates of amputation compared to non-MDRO patients. Similar results were found with mortality rates.  

Conclusions: The authors concluded that the included studies did not find any significant association between the duration of a diabetic foot ulcer and MDRO infection. Furthermore, MDRO diabetic infections were associated with poorer clinical outcomes in not only healing time, length of hospital stay, but also amputation and mortality rates. Personally, I found their first conclusion to be the most interesting. One would expect that patient who have had ulcers of prolonged duration would have likely underwent multiple rounds of antibiotics and that any residual bacteria subsequently developed resistance; however, this was not the case. I feel this would simplify antibiotic selection in patients with chronic foot ulcerations. The results from their secondary aim were expected. Poorer outcomes are associated with MDRO infection and should drive clinicians to promote preventative treatment. 

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