title: Motility and flagellin gene expression in the fish pathogen Vibrio salmonicida: effects of salinity and temperature.
abstract: The success of several Vibrio species, including Vibrio cholerae, Vibrio anguillarum and Vibrio fischeri in colonizing their symbiont, or causing infection is linked to flagella-based motility. It is during early colonization or the initial phase of infection that motility appears to be critical. In this study we used Vibrio salmonicida, a psychrophilic and moderate halophilic bacterium that causes cold-water vibriosis in seawater-farmed Atlantic salmon (Salmo salar), to study motility and expression of flagellins under salt conditions mimicking the initial and later phases of an infection. Our results, which are based on motility in semi-solid agar, membrane protein proteomics, quantitation of flagellin gene expression, challenge infection of fish, and microscopy, show that V. salmonicida is highly motile, expresses elevated levels of flagellins, and typically contains several polar flagella under salt conditions that are seawater-like. In contrast, V. salmonicida cells are non-motile and express significantly lower levels of flagellins under physiological-like salt conditions.
authors.affiliation: Department of Molecular Biotechnology, Institute of Medical Biology, Faculty of Medicine, University of Tromsø, MH-Building, N-9037 Tromsø, Norway.
authors.forename: Christian
authors.initials: C
authors.lastname: Karlsen
authors.forename: Steinar M
authors.initials: SM
authors.lastname: Paulsen
authors.forename: Hege Smith
authors.initials: HS
authors.lastname: Tunsjø
authors.forename: Simone
authors.initials: S
authors.lastname: Krinner
authors.forename: Henning
authors.initials: H
authors.lastname: Sørum
authors.forename: Peik
authors.initials: P
authors.lastname: Haugen
authors.forename: Nils-Peder
authors.initials: NP
authors.lastname: Willassen
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000382:microbiology*; D005408:Flagellin / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D020317:Salmo salar; D012965:Sodium Chloride / Q000378:metabolism*; D013696:Temperature; D014733:Vibrio / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D014735:Vibrio Infections / Q000382:microbiology / Q000662:veterinary*
chemical_list: D005408:Flagellin; D012965:Sodium Chloride