The Role of Plasmids in Antibiotic-resistance: Klebsiella pneumoniae as a Model
Plasmids are extrachromosomal DNA molecules that replicate within bacterial cells. These mobile genetic elements play a critical role in bacterial evolution, particularly in the adaptation to environmental pressures such as antibiotic exposure. Plasmids can carry genes that confer various survival advantages, including antibiotic resistance genes (ARGs). Through horizontal gene transfer (HGT), plasmids enable rapid genetic exchange between bacterial populations, facilitating the spread of resistance traits across species and genera. As a result, plasmids are central players in the emergence and dissemination of multidrug-resistant (MDR) and extensively drug-resistant (XDR) pathogens, including Klebsiella pneumoniae (K. pneumoniae), a leading cause of hospital-associated infections.
In this review, we focus on the role of plasmids in the evolution of antibiotic resistance in K. pneumoniae, with a particular emphasis on the molecular mechanisms underlying plasmid-mediated resistance and their contribution to the global crisis of antimicrobial resistance.