[Bacteremias due to multidrug-resistant microorganisms]

Bacteremias caused by multidrugresistant bacteria (MDRB) represent a growing public health issue, associated with high morbidity and mortality, prolonged hospitalization, and limited treatment options. The principal objective was to describe the frequency, clinical and microbiological characteristics, and risk factors associated with MDRB bacteremia in adult patients hospitalized in two tertiary-level centers in Córdoba, Argentina.

Retrospective, observational and analytical cohort study. Included patients =18 years with true positive blood cultures, from January 2020 to February 2021. Clinical, microbiological features and 30-day mortality were analyzed. Multivariate analysis identified risk factors for MDRB bacteremia.

A total of 403 bacteremia episodes were identified, 155 (38.4%) due to MDRB. Thirty-day mortality was higher in MDRO-BSI compared to non-MDRB cases (33.5% vs. 21.8%; p=0.009). Gram-negative bacilli predominated, especially Klebsiella pneumoniae and Escherichia coli. Independent risk factors included: current hospitalization >48 h (aOR: 1.96), ICU admission in the past 6 months (aOR: 1.83), prior antibiotic use within 6 months (aOR: 1.74), and diabetes mellitus (aOR: 1.98).

Bacteremias caused by MDRB accounted for a substantial proportion of bloodstream infections and were associated with higher mortality. Identifying risk factors enables the optimization of diagnostic and therapeutic strategies, promoting more efficient and targeted patient care.