Abstract
BACKGROUND: Klebsiella pneumoniae bloodstream infection (KP BSI) is a severe clinical condition characterized by high mortality rates. Despite the clinical significance, accurate predictors of mortality in KP BSI have yet to be fully identified. METHODS: A retrospective analysis was conducted on the clinical data of 90 cases of KP BSI. The clinical data was extracted from electronic medical records. Antimicrobial susceptibility testing, string testing, and whole-genome sequencing (WGS) were performed on all isolates. Additionally, relevant bioinformatics analyses, such as phylogenetic analysis and assessment of resistance and virulence genes, were carried out. Logistic regression modeling was employed to evaluate the risk factors associated with 28-day mortality in patients with KP BSI, considering both host characteristics and the characteristics of the causative Klebsiella pneumoniae (KP) isolates. RESULTS: Among the 90 patients included in this study, the 28-day mortality rate for those with KP BSI was 30.00% (27/90). Multivariate analysis revealed several host-related factors associated with an increased risk of 28-day mortality. These factors included an elevated qSOFA score (odds ratio [OR] 2.98, 95% confidence interval [CI] 1.21-7.31, p = 0.017), presence of septic shock (OR 8.21, 95% CI 1.63-41.93, p = 0.008), and nosocomial infection (OR 7.72, 95% CI 1.71-34.74, p = 0.002). Regarding bacterial factors, the presence of the virulence genes rfbA/B/D (OR 8.53, 95% CI 1.41-51.57, p = 0.020) was identified as an independent risk factor, particularly for nosocomial infection patients. However, hypermucoviscosity phenotype, ST type, serotype, and resistance genes were not associated with an increased risk of 28-day mortality. CONCLUSION: The carriage of virulence genes rfbA/B/D, which is responsible for the synthesis of O-antigen, was associated with poor prognosis of KP BSI. It may facilitate the clinical management of patients with bloodstream infection (BSI) caused by hypervirulent KP strains, especially those with rfbA/B/D genes. CLINICAL TRIAL NUMBER: Not applicable.