Quorum sensing and regulation of virulence factors in salmonella infection

Lines connect the coordinator with its partners. CORDIS does not always give exact coordinates for projects before 2014. These points are placed at city or country level.

Project objective

The human pathogen Salmonella remains a significant ongoing threat to worldwide public health. Although major advances have been made with respect to the understanding of Salmonella-specific host pathogen interaction, the nature and the regulation of bacterial virulence effectors directly responsible for the host response remains elusive. Quorum sensing constitutes a bacterial cell-cell communication system in which bacterial secreted auto-inducing molecules signal and trigger changes in gene expression. Such systems can act as global regulators of virulence like in Staphylococcus aureus. In Salmonella typhimurium, the quorum sensing auto-inducer AI-2 is the final product in a biosynthetic pathway involving the AI-2 synthesis encoded by the luxS gene. Recent reports indicate that AI-2 plays a role in the coordination of virulence in Escherichia coli and Streptococcus pyogenes . However , the role of quorum sensing mechanisms in Salmonella pathogenicity has not been investigated yet. With this project, I intend to explore the role of AI-2 in regulating Salmonella virulence. A luxS-null mutant will be constructed and compared with the parent in its ability to infect and colonize the host by using cultured human epithelial intestinal cells, cultured mouse macrophages and a mouse model of systemic infection. Effects of AI-2 in regulating expression of Salmonella pathogenicity islands (SPI-1 and SPI-2)-encoded virulence factors including the components of the type III secretion systems will be analyzed in vitro and in vivo. Finally, the function of AI-2 as a regulator involved directly in infection and stimulation of host signaling cascades will be studied.

Original text from CORDIS.

Participants

• N/ACoordinatorCity levelUnknown Region

Links

• View on CORDIS