Mecanismos de interacción y defensa de Klebsiella pneumoniae frente a la infección por fagos

Laburpena

Bacteriophages, also known as "phages", are viruses that infect bacteria. These viruses that target prokaryotes are considered the most abundant biological entity on the Earth, with an estimated population size of 1031 viral particles. Antimicrobial resistance is the cause of dubious success rates of antibiotics against an increasing number of bacterial pathogens. Therefore, the rapid spread of multidrug-resistant pathogens has renewed interest in the use of phages. Bacteria and phages are in a constant state of coevolution known as arms race, as when one develops a mechanism to evade the other, it triggers the evolution of the latter to overcome this defence. Thus, bacteria have developed defense mechanisms to protect themselves from their predators, while phages, in turn, have developed counterdefense strategies to evade these systems. In this context, this doctoral thesis focused on studying the mechanisms of interaction and defense of Klebsiella pneumoniae against phage infection. Accordingly, the first chapter of this doctoral thesis involved genomic analysis of 40 prophages located in the genomes of 16 clinical isolates of carbapenemase-carrying K. pneumoniae. In the second chapter, the role of the type II toxin-antitoxin system PemK/PemI in a clinical isolate of K. pneumoniae in lytic phage infection was studied. Finally, in the third chapter, proteomic analysis was carried out to investigate the interaction between phages and their bacterial host K. pneumoniae.