Abstract / Summary
Abstract Background Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a growing health threat in intensive care units (ICUs), where infections often have limited therapeutic options and demonstrate high mortality. However, the relative contribution of antimicrobial resistance versus host-related factors to clinical outcomes remains unclear. This study aimed to evaluate the clinical determinants, molecular resistance patterns, and 90-day mortality associated with CRKP infections in patients admitted to the ICU. Methods Conducted between October 2023 and October 2024 in several ICUs of a single tertiary-care hospital, this prospective cohort study included adult patients with culture-confirmed K. pneumoniae infections. They were classified into CRKP (n = 96) and carbapenem-susceptible (CSKP, n = 57) groups. Demographic characteristics, comorbidities, invasive procedures, prior antibiotic exposure, and clinical outcomes were recorded. Polymerase chain reaction was used for detecting carbapenemase genes ( OXA-48 , NDM , KPC , VIM , IMP ), and multivariate logistic regression was performed to identify independent risk factors for carbapenem resistance and 90-day mortality. Results Univariate analysis revealed that advanced age, hemodialysis, steroid use, central venous catheterization, and mechanical ventilation were significantly associated with CRKP. In the multivariate analysis, age, central venous catheterization, and recent Gram-negative infection (within the previous 3 months) independently predicted carbapenem resistance. The predominant resistance gene was OXA-48 (67.1%), followed by NDM (49.4%) and KPC (31.7%); all NDM -positive isolates coharbored OXA-48 . The 90-day mortality rate did not significantly differ between the two groups (CRKP, 51.9%; CSKP, 66%). Advanced age, malignancy, chronic kidney disease, and mechanical ventilation independently predicted mortality. IMP was the only resistance gene significantly associated with mortality. Conclusions Carbapenem resistance was associated with distinct clinical and molecular characteristics but was not independently linked to increased 90-day mortality in ICU patients with K. pneumoniae infections. Host-related factors and invasive support measures strongly determined clinical outcomes. Rapid molecular detection of resistance genes and optimization of invasive device management remain essential for improving ICU infection control and patient prognosis.