Project name: Transcriptome comparison of the Streptococcus pneumoniae D39 ∆rgg939 to D39 wild type grown in galactose

Description: Microbes communicate with each other by using quorum sensing (QS) systems and modulate their collective ‘behavior’ for in-host colonization and virulence, biofilm formation, and environmental adaptation. The recent increase in genome data availability reveals the presence of several putative QS sensing circuits in microbial pathogens, but many of these have not been functionally characterized yet, despite their possible utility as drug targets. To increase the repertoire of functionally characterized QS systems in bacteria, we studied Rgg144/Shp144 and Rgg939/Shp939, two putative QS systems in the important human pathogen Streptococcus pneumoniae. We find that both of these QS circuits are induced by short hydrophobic peptides (Shp) upon sensing sugars found in the respiratory tract, such as galactose and mannose. Microarray analyses using cultures grown on mannose and galactose revealed that the expression of a large number of genes is controlled by these QS systems, especially those encoding for essential physiological functions and virulence-related genes such as the capsular locus. Moreover, the array data revealed evidence for cross-talk between these systems. Finally, these Rgg systems play a key role in colonization and virulence, as deletion mutants of these QS systems are attenuated in the mouse models of colonization and pneumonia.Overall design: Transcriptome comparison of the Streptococcus pneumoniae D39 ∆rgg939 to D39 wild type grown in 55mM galactose until early exponential phase (corresponded to OD600 of 0.3)One condition design comparision of two strains including a dye swap

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Medical

Last updated: 2018-03-23