title: The DSF type quorum sensing signalling system RpfF/R regulates diverse phenotypes in the opportunistic pathogen Cronobacter.
abstract: Several bacterial pathogens produce diffusible signal factor (DSF)-type quorum sensing (QS) signals to control biofilm formation and virulence. Previous work showed that in Burkholderia cenocepacia the RpfFBc/RpfR system is involved in sensing and responding to DSF signals and that this signal/sensor gene pair is highly conserved in several bacterial species including Cronobacter spp. Here we show that C. turicensis LMG 23827(T) possesses a functional RpfF/R system that is involved in the regulation of various phenotypes, including colony morphology, biofilm formation and swarming motility. In vivo experiments using the zebrafish embryo model revealed a role of this regulatory system in virulence of this opportunistic pathogen. We provide evidence that the RpfF/R system modulates the intracellular c-di-GMP level of the organism, an effect that may underpin the alteration in phenotype and thus the regulated phenotypes may be a consequence thereof. This first report on an RpfF/R-type QS system of an organism outside the genus Burkholderia revealed that both the underlying molecular mechanisms as well as the regulated functions show a high degree of conservation.
authors.affiliation: Department of Microbiology, University of Zurich, CH-8008 Zurich, Switzerland.
authors.forename: Angela
authors.initials: A
authors.lastname: Suppiger
authors.affiliation: Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
authors.forename: Athmanya Konegadde
authors.initials: AK
authors.lastname: Eshwar
authors.affiliation: Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
authors.forename: Roger
authors.initials: R
authors.lastname: Stephan
authors.affiliation: Research Core UnitMetabolomics, Hannover Medical School, D-30625 Hannover, Germany.
authors.forename: Volkhard
authors.initials: V
authors.lastname: Kaever
authors.affiliation: Department of Microbiology, University of Zurich, CH-8008 Zurich, Switzerland.
authors.forename: Leo
authors.initials: L
authors.lastname: Eberl
authors.affiliation: Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
authors.forename: Angelika
authors.initials: A
authors.lastname: Lehner
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis; D018441:Biofilms; D015374:Biosensing Techniques; D059126:Cronobacter / Q000472:pathogenicity / Q000502:physiology*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D010447:Peptide Hydrolases / Q000096:biosynthesis; D010641:Phenotype; D053038:Quorum Sensing; D015027:Zebrafish
chemical_list: D001426:Bacterial Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D010447:Peptide Hydrolases; D006152:Cyclic GMP