The mechanisms of antibiotic resistance and drug resistance transmission of Klebsiella pneumoniae.

Klebsiella pneumoniae is a ubiquitous Gram-negative pathogen in clinical settings, responsible for pulmonary infections, urinary tract infections, septicemia, and other severe diseases.Over recent years, widespread use of aminoglycosides, quinolones, and β-lactams has driven a marked increase in antimicrobial resistance, compromising treatment efficacy. Here, we review the molecular bases of K. pneumoniae drug resistance, focusing on β-lactamase production, efflux-pump overexpression, target-site modifications, and reduced membrane permeability. We also examine the horizontal spread of resistance determinants via plasmids, integrons, and transposons. By integrating these mechanisms with their transmission pathways, this review provides a comprehensive framework to inform rational antibiotic selection, guide infection-control policies, and support the development of novel anti-resistance strategies.