Estudio del "quorum sensing" en "Acinetobacter baumannii"implicaciones clínicas

Abstract

In recent years, bacterial intercellular communication, which plays an important role in the regulation of different virulence factors, has been of great interest. Bacteria are able to exchange information using cell-to cell communication systems, known as quorum sensing (QS), based in chemical signaling molecules. This process allows the bacteria to share information about cell density and regulate gene expression accordingly. Therefore, QS could be a key target to seek and to design new therapeutic alternatives for the treatment of infections caused by multidrug resistant pathogens, such as Acinetobacter baumannii. This pathogen not only shows an intrinsic resistance to a multitude of antibiotics, but also possesses a great facility to acquire genetic elements and/or mutations increasing its multidrug resistance phenotype, which makes it one of the main microorganisms that cause nosocomial infections worldwide. Inhibition of communication between bacteria (quorum quenching) may be performed by different approaches such as inhibition of signal molecules synthesis, interference of these signal molecules by enzymatic degradation (by acylase or lactones) or by using receptor antagonists of these signal molecules. In the present doctoral thesis, the quorum sensing/quorum quenching systems of different clinical strains of A. baumannii and their relationship with various stress conditions (ROS response, bile salts and lytic/lysogenic phages) are studied in order to develop new anti-infective therapies (known as anti-viral therapies) that allow inhibiting bacterial mobility, biofilm formation and thus the development of infection.