Rising global threat of hypervirulent Klebsiella pneumoniae: Insights into virulence factors, pathogenicity, and molecular mechanisms.

Hypervirulent Klebsiella pneumoniae, a novel variant with unique phenotypic and genotypic features that enhance pathogenicity and epidemic potentiality, has become a serious worldwide public health emergency. Even healthy people can contract invasive infections from hypervirulent K. pneumoniae (hvKp), which shows higher virulence than classical K. pneumoniae (cKp). Because of its colonization in the human gut, it can spread and cause serious morbidity in community-acquired diseases like meningitis, endophthalmitis, and liver abscesses. To increase its pathogenic potential, hvKp possesses a distinct collection of virulence factors that go beyond antibiotic resistance. Capsule, fimbriae, siderophores and LPS are the major essential elements responsible for pathogenicity. Siderophores are a major class of secondary metabolites that play a key role in facilitating the transport of iron across bacterial cell membranes into the cytoplasm. This review examines numerous virulence factors that contribute to the infectious capacity of hvKp, including the polysaccharide capsule, biofilm formation, siderophore production (aerobactin, enterobactin, salmochelin, and yersiniabactin), and adhesins involved in host cell colonization and pathogenicity. Additionally, this review may evaluate the specific role of virulence regulatory genes in balancing antibiotic resistance and pathogenicity. Understanding these virulence genes and their mechanisms is essential for the development of effective diagnostic, preventive, and therapeutic approaches to address the escalating threat of hvKp pathogenesis. This is a novel and impactful review that should go beyond the description of virulence factors and pathogenicity and should highlight how understanding these mechanisms can inform the development of novel therapeutic strategies against hypervirulent Klebsiella pneumoniae (hvKp).