Clinical and molecular characteristics, antibiotic susceptibility, risk factors and predictors of mortality in carbapenem-resistant klebsiella pneumoniae bloodstream infections in Southern Sichuan, China: a 5-year multicenter study.

Background: The World Health Organization (WHO) has listed carbapenem-resistant Methods: Clinical and laboratory electronic medical records of patients with KP-BSI were collected retrospectively. T-tests, Mann-Whitney U tests, logistic regression, and survival curve analyses were used to assess risk factors and mortality predictors. Strains were re-identified and verified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing was performed using the microbroth dilution method. Molecular typing was based on multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Capsular serotypes, virulence genes, and virulence phenotypes were detected using polymerase chain reaction (PCR), sequencing, and serum resistance assays. Results: A total of 430 cases meeting the criteria were included, of which 66 were CRKP BSI cases. The highest isolation rate of CRKP BSI was in the intensive care unit (ICU, 28.8%). The resistance rate of CRKP to carbapenems was above 92.2%, and the 28-day mortality rate of CRKP-BSI patients was 43.9%. Multivariate analysis showed that pulmonary infection ( Conclusion: Carbapenem-resistant Klebsiella pneumoniae (CRKP) in southern Sichuan, China, is characterized by high resistance rates, the continuous emergence of novel clones, and elevated patient mortality. These findings underscore the urgent need for enhanced surveillance that integrates clinical and molecular epidemiology with targeted interventions. This study provides a robust scientific foundation for optimizing the clinical management of CRKP bloodstream infections. This study provides a scientific basis for optimizing clinical management strategies for CRKP-BSI.