# Genomic and Clinical Profile of Hypervirulent Klebsiella pneumoniae (ST23-K1) Liver Abscesses: Experience with Patients at a Romanian University Hospital

## TL;DR

This study describes the genomic and clinical features of a dangerous liver infection caused by a specific strain of Klebsiella pneumoniae in Romania.

## Contribution

The study provides the first detailed molecular characterization of hypervirulent Klebsiella pneumoniae (ST23-K1) liver abscesses in Romania.

## Key findings

- Most hvKp isolates were phenotypically susceptible, but one showed extended-spectrum beta-lactamase (ESBL) resistance.
- Genomic analysis revealed genetic diversity among hvKp isolates, indicating community acquisition rather than a hospital outbreak.
- The ST23-K1 lineage was confirmed to carry key virulence genes like rmpA, iuc, and peg-344.

## Abstract

Introduction: Hypervirulent Klebsiella pneumoniae (hvKp) is an emerging global pathogen that causes severe liver abscesses and metastatic infections. Despite rising concerns regarding multidrug-resistant convergence, molecular data in Romania remain limited. This study characterizes the epidemiological, clinical, and genomic profiles of hvKp liver abscesses in a tertiary hospital, aiming to describe the local virulence landscape and inform clinical management. Results: This study characterizes 15 cases of hvKp liver abscesses in a tertiary hospital. The cohort was predominantly male, with high rates of type 2 diabetes. Although clinical presentation was severe, featuring complications like endogenous endophthalmitis, the outcomes following prolonged antibiotic therapy were generally favorable. Phenotypically, 93.3% of isolates retained a wild-type susceptible profile, while a single ESBL-positive case highlighted the risk of resistance convergence. Genomic sequencing confirmed the presence of the ST23-K1 pandemic lineage carrying key virulence determinants (rmpA, iuc, and peg-344). Crucially, cgMLST analysis revealed genetic heterogeneity, suggesting sporadic community acquisition rather than a clonal nosocomial outbreak. Conclusions: These findings represent the first detailed molecular description of hvKp in Romania, confirming the local circulation of high-risk ST23 clones and underscoring the necessity for early detection and surveillance.