CONICET | Buscador de Institutos y Recursos Humanos

Serratia are ubiquitous bacteria that can be isolated from a wide variety of environmental niches, ranging from water and soil to air. In particular, S. marcescens is an emerging health-threatening opportunistic pathogen. Outbreaks due to S. marcescens strains resistant to multiple antibacterial agents and high incidence in intensive and neonatal care units are increasingly being reported. The Word Health Organization has included Serratia in the priority list of bacteria in which research efforts should be emphasized for the development of new antimicrobial agents to counteract infections. In addition, S. marcescens has recently been identified as one of the three most abundant microbial species that colonizes the dysbiotic intestine of Crohn?s patients, in detriment of beneficial bacteria. Despite this, few reports have in-depth characterized the mechanisms that Serratia employs to invade, survive and disseminate within and outside the host. My group has recently investigated the mechanisms that control the virulence of this bacterium, disclosing the key role of the Rcs signal transduction system in the control of the effectors required for the interaction of Serratia with the host. This signal-transduction system also finely tunes the firing of the Type VI Secretion System in the competition struggle against other bacteria such as those encountered in the gut of the infected host. We have also explored the role of a secreted metalloprotein in the ability of Serratia to form biofilms. Finally, our recent advances in the understanding of the invasion process of S. marcescens to host cells, which reveal intracellular trafficking mechanisms and the strategy deployed by the pathogen to escape and spread outside the invaded cell, will be discussed.