Work

Prevalence, characteristics and clinical features of hypervirulent Klebsiella pneumoniae in a German university hospital

Year: 2025

Type: article

Abstract: BACKGROUND: Infections caused by hypervirulent Klebsiella pneumoniae (hvKp) are often characterised by severe, metastatic and relapsing infections. Initially described in Asia, this pathotype has now expanded worldwide. Convergent strains combining hypervirulence with multidrug resistance additionally aggravate the situation. However, only sparse data are available on the occurrence of hvKp in European countries. Therefore, this study investigated the prevalence of hvKp in a tertiary medical centre in Germany. METHODS: K. pneumoniae isolates were prospectively collected from clinical specimens obtained at the University Medicine Greifswald from June 1st to August 31st, 2022. Only the first isolate from each patient was considered, while screening samples were excluded. All isolates were phenotypically characterised for virulence and subjected to whole genome sequencing (WGS). RESULTS: ). Phenotypic assays showed heterogeneous results, with only one isolate demonstrating concomitant positivity in both the string test and mucoid-staining plate. WGS revealed 81 different sequence types, including high-risk clonal lineages. Four isolates carried typical genetic markers associated with hypervirulence and were largely antibiotic-susceptible. In the Galleria mellonella infection model, these four isolates showed higher larval mortality compared to two control carbapenem-resistant classical K. pneumoniae strains. Convergent strains were not found. CONCLUSION: Our findings revealed that 3.3 % (4 out of 122) of isolates were classified as hvKp. This prevalence appears clinically relevant due to the notoriously aggressive course of infections caused by this pathotype.

Source: International Journal of Medical Microbiology

DOI: 10.1016/j.ijmm.2025.151662