title: Identification of genes induced in Vibrio cholerae in a dynamic biofilm system.
abstract: The facultative human pathogen Vibrio cholerae, the causative agent of the severe secretory diarrheal disease cholera, persists in its aquatic reservoirs in biofilms during interepidemic periods. Biofilm is a likely form in which clinically relevant V. cholerae is taken up by humans, providing an infective dose. Thus, a better understanding of biofilm formation of V. cholerae is relevant for the ecology and epidemiology of cholera as well as a target to control the disease. Most previous studies have investigated static biofilms of V. cholerae and elucidated structural prerequisites like flagella, pili and a biofilm matrix including extracellular DNA, numerous matrix proteins and exopolysaccharide, as well as the involvement of regulatory pathways like two-component systems, quorum sensing and c-di-GMP signaling. However, aquatic environments are more likely to reflect an open, dynamic system. Hence, we used a biofilm system with constant medium flow and a temporal controlled reporter-system of transcription to identify genes induced during dynamic biofilm formation. We identified genes known or predicted to be involved in c-di-GMP signaling, motility and chemotaxis, metabolism, and transport. Subsequent phenotypic characterization of mutants with independent mutations in candidate dynamic biofilm-induced genes revealed novel insights into the physiology of static and dynamic biofilm conditions. The results of this study also reinforce the hypotheses that distinct differences in regulatory mechanisms governing biofilm development are present under dynamic conditions compared to static conditions.
authors: University of Graz, Institute of Molecular Biosciences, Graz, Austria.
authors: Andrea
authors: A
authors: Seper
authors: University of Graz, Institute of Molecular Biosciences, Graz, Austria.
authors: Katharina
authors: K
authors: Pressler
authors: University of North Carolina at Chapel Hill, Department of Microbiology and Immunology, Chapel Hill, NC, USA.
authors: Ankunda
authors: A
authors: Kariisa
authors: University of Graz, Institute of Molecular Biosciences, Graz, Austria.
authors: Andrea G
authors: AG
authors: Haid
authors: University of Graz, Institute of Molecular Biosciences, Graz, Austria.
authors: Sandro
authors: S
authors: Roier
authors: University of Graz, Institute of Molecular Biosciences, Graz, Austria.
authors: Deborah R
authors: DR
authors: Leitner
authors: University of Graz, Institute of Molecular Biosciences, Graz, Austria.
authors: Joachim
authors: J
authors: Reidl
authors: University of North Carolina at Chapel Hill, Department of Microbiology and Immunology, Chapel Hill, NC, USA.
authors: Rita
authors: R
authors: Tamayo
authors: University of Graz, Institute of Molecular Biosciences, Graz, Austria. Electronic address: stefan.schild@uni-graz.at.
authors: Stefan
authors: S
authors: Schild
mesh_terms: D019677:Artificial Gene Fusion; D018441:Biofilms / Q000254:growth & development*; D004783:Environmental Microbiology; D020869:Gene Expression Profiling; D005798:Genes, Bacterial; D017930:Genes, Reporter; D006801:Humans; D014734:Vibrio cholerae / Q000235:genetics / Q000502:physiology*
keywords: Biofilm; Cholera; Dynamic; Flow cell; c-di-GMP