Immunological analysis of Klebsiella pneumoniae infected patients

The expression of enterobactin is practically ubiquitous among the classical and HV strains of KP, which is why it is considered their primary iron absorption system. In the case of the other siderophores, their expression is less conserved. Genes involved in enterobactin biosynthesis are located on the KP chromosome, in the entABCDEF gene cluster. On the other hand, the fepABCDG gene group encodes the proteins that mediate the transport of enterobactin and its secretion to the extracellular medium. FepA specifically encodes the uptake receptor expressed on the cell surface, and responsible for the internalization of iron sequestered by enterobactin itself. Microorganisms are essential to life on Earth as we understand it today. On the one hand, microorganisms generate biomass from nutrients in the environment thanks to different metabolic processes. On the other hand, they are responsible for the recycling of nutrients and the degradation of organic matter, both essential functions for the proper functioning of the life cycle of an ecosystem. However, many species have adapted throughout evolution to a pathogenic way of life, causing serious consequences for human health, as will be seen throughout this introduction in the specific case of the species that is the protagonist of this thesis. , Klebsiella pneumoniae. Antibiotic resistance is increasing worldwide to dangerous levels. New resistance mechanisms are emerging and spreading across the planet, jeopardizing our ability to treat even common infectious diseases. A growing number of infections, including pneumonia, septicemia, urinary, wounds or even some food or sexually transmitted diseases, are increasingly difficult (and sometimes impossible) to treat, as antibiotics lose their effectiveness. If effective antibiotics are not available to prevent and treat infections, many common and minor infections will become life-threatening again, while seriously compromising other medical techniques/interventions that rely heavily on prophylactic antibiotic treatments, such as transplants, cancer therapy and surgeries. This situation highlights the need to understand the bacterial or host mechanisms (especially at the level of cell signaling) that favor the development of the infection in order to find new therapeutic targets and deal with the serious problem posed by multi-resistant infections.