Homeostatic interplay between bacterial cell-cell signaling and iron in virulence
Rahme, L. G.
Google Scholar check
MetadataShow full item record
Pathogenic bacteria use interconnected multi-layered regulatory networks, such as quorum sensing (QS) networks to sense and respond to environmental cues and external and internal bacterial cell signals, and thereby adapt to and exploit target hosts. Despite the many advances that have been made in understanding QS regulation, little is known regarding how these inputs are integrated and processed in the context of multi-layered QS regulatory networks. Here we report the examination of the Pseudomonas aeruginosa QS 4-hydroxy-2-alkylquinolines (HAQs) MvfR regulatory network and determination of its interaction with the QS acyl-homoserine-lactone (AHL) RhlR network. The aim of this work was to elucidate paradigmatically the complex relationships between multi-layered regulatory QS circuitries, their signaling molecules, and the environmental cues to which they respond. Our findings revealed positive and negative homeostatic regulatory loops that fine-tune the MvfR regulon via a multi-layered dependent homeostatic regulation of the cell-cell signaling molecules PQS and HHQ, and interplay between these molecules and iron. We discovered that the MvfR regulon component PqsE is a key mediator in orchestrating this homeostatic regulation, and in establishing a connection to the QS rhlR system in cooperation with RhlR. Our results show that P. aeruginosa modulates the intensity of its virulence response, at least in part, through this multi-layered interplay. Our findings underscore the importance of the homeostatic interplay that balances competition within and between QS systems via cell-cell signaling molecules and environmental cues in the control of virulence gene expression. Elucidation of the fine-tuning of this complex relationship offers novel insights into the regulation of these systems and may inform strategies designed to limit infections caused by P. aeruginosa and related human pathogens. © 2010 Hazan et al.
Showing items related by title, author, creator and subject.
A quorum sensing regulated small volatile molecule reduces acute virulence and promotes chronic infection phenotypes Kesarwani, M.; Hazan, R.; He, J.; Que, Y.; Apidianakis, Yiorgos; Lesic, B.; Xiao, G.; Dekimpe, V.; Milot, S.; Déziel, Eric; Lépine, F.; Rahme, L. G. (2011)A significant number of environmental microorganisms can cause serious, even fatal, acute and chronic infections in humans. The severity and outcome of each type of infection depends on the expression of specific bacterial ...
Use of molecular beacons and multi-allelic real-time PCR for detection of and discrimination between virulent Bacillus anthracis and other Bacillus isolates Hadjinicolaou, Andreas V.; Demetriou, Victoria L.; Hezka, Johana; Beyer, W.; Hadfield, T. L.; Kostrikis, Leontios G. (2009)The awareness of the threat of Bacillus anthracis, the causative agent of the disease anthrax, as a biowarfare and bioterrorism weapon has revived the development of new technologies for rapid and accurate detection of ...
Molecular beacon-based real-time PCR detection of primary isolates of salmonella typhimurium and salmonella enteritidis in environmental and clinical samples Hadjinicolaou, Andreas V.; Demetriou, Victoria L.; Emmanuel, M. A.; Kakoyiannis, C. K.; Kostrikis, Leontios G. (2009)Background. A fast and simple two-step multiplex real-time PCR assay has been developed to replace the traditional, laborious Salmonella serotyping procedure. Molecular beacons were incorporated into the assay as probes ...