Risk factors for methicillin-resistant Staphylococcus aureus and extended-spectrum ß-lactamase-producing Enterobacterales in patients with diabetic foot infections requiring hospital admission

OBJECTIVE: Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) may complicate the treatment of diabetic foot infections (DFIs). The aim of this study was to determine the risk factors for these pathogens in DFIs. METHODS: This was a prospective observational study of 167 consecutive adult patients with DFIs. The diagnosis and severity of DFIs were based on the Infectious Disease Society of America (IDSA) classification system. Multivariate analyses were performed in order to identify risk factors for MRSA and ESBL-E infections. RESULTS: S. aureus was the most isolated pathogen (n=82, 37.9 %) followed by Escherichia coli (n= 40, 18.5%). MRSA accounted for 57.3% of all S. aureus and 70% of Klebsiella pneumoniae and 25% of E. coli were ESBL producers, respectively. Deep ulcer [OR 8,563; 95% CI (1,068-4,727)], previous use of fluoroquinolones [OR 2,78; 95% CI (1,156-6,685)] and peripheral vasculopathy [OR 2,47; 95% CI (1.068-4.727)] were the independent predictors for MRSA infections; and osteomyelitis [OR 6,351; 95% CI (1,609-25,068)] and previous use of cephalosporins [OR 5,824; 95% CI (1,517-22,361)] for ESBL-E infections. CONCLUSIONS: MRSA and ESBL-E have adquired a great clinical relevance in DFIs. The availability of their risk factors is very convenient to choose the empirical treatment in severe forms.