Project

Our project is focused on the intracellular life of Brucella abortus, the causative agent of bovine brucellosis. B. abortus is a facultative extracellular-intracellular pathogen that upon infection of its mammalian host, invades professional phagocytes in which the bacterium transits into the Brucella-containing vacuole and reaches its replicative niche, the endoplasmic reticulum (ER). A key element required for B. abortus intracellular replication is the BvrR/BvrS two-component system. Previous results support a model where B. abortus, upon entrance to host cells, senses the transition from the extracellular to the intracellular milieu through BvrR/BvrS (Altamirano-Silva et al, 2018). Intracellularly, the regulatory protein BvrR is activated by phosphorylation in response to intracellular cues found in early compartments, such as low pH and nutrient deprivation. BvrR activation triggers the expression of virulence factors as the Type Four Secretion System, VirB, essential for trafficking to the ER. We intend to analyse the transcriptome of BvrR dominant positive and negative BvrR mutants (by comparing to the wild type transcriptome) in order to understand the set of factors regulated by modulating the expression of this system.