Work

Clinical features and microbiological analysis of risk factors for mortality among patients with carbapenem-resistant Klebsiella pneumoniae bacteremia: A changing virulence landscape

Year: 2025

Type: article

Abstract: OBJECTIVE: The global rise of carbapenem-resistant Klebsiella pneumoniae bloodstream infection (CRKP-BSI) is alarming due to its link to increased morbidity and mortality from limited treatment options. This study evaluated the impact of virulence plasmid carriage on CRKP-BSI mortality. METHODS: A matched case-control study was conducted among 93 CRKP patients, 23 of whom tested positive for virulence plasmids. The clinical and bacterial characteristics of CRKP-induced BSIs with and without virulence plasmids were analyzed. RESULTS: Virulence plasmids were present in 24.7 % of CRKP strains, with a 61.1 % mortality rate among patients with virulence plasmid-positive CRKP (pV-CRKP) infections. The ST11-KL64 subtype was predominant in Jiangxi Province. Molecular typing revealed pV-CRKP strains primarily had two identical genotypes, yet virulence plasmids were present across various PFGE genotypes, indicating polymorphic distribution. Logistic regression identified community-acquired infection, neurology department admission, and stroke as independent risk factors. G. mellonella and biofilm assays showed most CRKP strains with virulence plasmids exhibited increased virulence, though some strains did not. CONCLUSION: Virulence plasmids generally heighten CRKP strain virulence and directly affect the 7-day survival rate. Certain strains carry virulence plasmids without increased virulence. Community-acquired infection, neurology department admission, and stroke are independent risk factors for pV-CRKP strains. The presence of IncFrepB among pV-CRKP may promote the spread of virulence genes in ST11-type CRKP.

Source: Journal of Microbiology Immunology and Infection

DOI: 10.1016/j.jmii.2025.12.001