Klebsiella pneumoniae and pyogenic liver abscess: Emerging clinical threats, virulence mechanisms and therapeutic strategies (Review)

Klebsiella pneumoniae has emerged as a leading cause of pyogenic liver abscess (PLA), driven by hypervirulent and multidrug-resistant (MDR) strains that pose major diagnostic and therapeutic challenges. This organism exhibits extensive capsular diversity (K1-K80), with serotypes K1, K2, K5, K20, K54 and K57 being the most associated with invasive infections and severe clinical outcomes. Increasing convergence between hypervirulence and MDR determinants threatens effective management worldwide. Pharmacological and safety limitations of current antibiotics, including nephrotoxicity of colistin, hepatotoxicity of tigecycline and poor drug penetration into abscess cavities, further complicate treatment and encourage exploration of non-traditional strategies such as anti-virulence or immunomodulatory approaches. Recent advancements in rapid diagnostic tools such as metagenomic sequencing, MALDI-TOF and point-of-care PCR assays offer promising prospects for early detection and antimicrobial optimization. Pharmacokinetic challenges at the abscess site and the emergence of hybrid hvKp-MDR strains emphasize the urgency of precision-guided therapy and robust global surveillance. K. pneumoniae‑associated PLA thus represents an evolving global health threat and understanding serotype diversity, antibiotic limitations and diagnostic innovations is essential for developing more effective preventive and therapeutic strategies. The present review provides current insights into the epidemiology, pathogenesis and therapeutic challenges of K. pneumoniae-associated PLA, while highlighting translational opportunities and research priorities to counter the escalating dual threat of hypervirulence and resistance.