Article’s

Abstract: Klebsiella pneumoniae is a Gram-negative opportunistic pathogen that has emerged as a major cause of healthcare-associated infections worldwide, including pneumonia, bloodstream infections, and urinary tract infections. Its clinical success is driven by a combination of extensive virulence determinants and an exceptional capacity to acquire antimicrobial resistance. Key virulence factors such as the polysaccharide capsule, lipopolysaccharide, fimbrial adhesins, and multiple iron-scavenging systems facilitate colonization, immune evasion, and invasive disease. Of particular concern is the global emergence of hypervirulent K. pneumoniae lineages, which cause severe community-onset infections and are increasingly converging with multidrug-resistant phenotypes. Carbapenem-resistant K. pneumoniae (CRKP) represents a critical public health threat, fueled by the dissemination of carbapenemase genes including blaKPC, blaNDM, blaOXA-48-like, and blaVIM, often carried on mobile genetic elements. In India and other high-burden regions, resistance is further amplified by porin loss, efflux pump overexpression, and horizontal gene transfer, contributing to high morbidity and mortality, particularly in intensive care settings. Environmental contamination, inappropriate antibiotic use, and inadequate infection control practices exacerbate the spread of CRKP. Accurate and timely detection remains challenging, especially in resource-limited settings, where phenotypic assays are widely used despite limited specificity, while molecular techniques offer greater sensitivity but limited accessibility. This review highlights the interplay between virulence, resistance mechanisms, epidemiology, and diagnostic challenges of K. pneumoniae, emphasizing the urgent need for integrated surveillance, improved diagnostics, and effective antimicrobial stewardship to curb the growing threat posed by carbapenem-resistant and hypervirulent strains. Keyword: Klebsiella pneumoniae, carbapenem resistance, antimicrobial resistance, Hypervirulent Klebsiella pneumoniae (hvKp), Virulence factors.