Risk factors and clinical characteristics of bloodstream infection caused by ESBL-producing Klebsiella pneumoniae.

INTRODUCTION: The aim of this study was to analyze the clinical characteristics and risk factors of bloodstream infections (BSI) caused by extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae (KP). METHODOLOGY: A retrospective study was conducted by enrolling clinically confirmed KP-BSI cases (2019-2023). Clinical data were collected and analyzed through review of the electronic medical records. Patients with ESBL-positive KP-BSI were compared to those with ESBL-negative KP-BSI. Multivariate logistic regression analysis was used to identify risk factors associated with ESBL-producing KP-BSI. RESULTS: A total of 199 patients were included, among whom 47 (23.6%) had ESBL-producing KP-BSI. Univariate analysis revealed that the proportion of patients undergoing surgery within 48 hours before blood sampling was higher in the ESBL-positive group than in the ESBL-negative group (40.4% vs. 23.0%, p < 0.05). Regarding infection source, liver-origin infections were less frequent in the ESBL-positive group compared to the ESBL-negative group (6.4% vs. 24.3%, p < 0.05), while urinary tract-origin infections were significantly more frequent in the ESBL-positive group (38.3% vs. 18.4%, p < 0.05). Hospital-acquired infection was more common in the ESBL-positive group than in the ESBL-negative group (40.4% vs. 23.7%, p < 0.05). Multivariate analysis identified urinary tract origin (adjusted odds ratio [aOR], 2.162; 95% confidence interval [CI], 1.003-4.661) as an independent risk factor for ESBL-producing KP-BSI. CONCLUSIONS: Primary urinary tract infections constitute an independent risk factor for ESBL-producing KP-BSI. Given the therapeutic complexity of ESBL-producing strains, KP-BSI of urinary tract origin warrant heightened clinical vigilance among clinicians.