title: Impact of mucin, bile salts and cholesterol on the virulence of Vibrio anguillarum towards gnotobiotic sea bass (Dicentrarchus labrax) larvae.
abstract: In this study, we investigated the impact of the host factors mucin, bile salts and cholesterol on the virulence of the economically important aquatic pathogen Vibrio anguillarum towards sea bass larvae. Pretreatment of V. anguillarum with either one of the host factors (at 10 mg l(-1)) prior to inoculation into the sea bass rearing water increased virulence of the bacterium, although the effect of cholesterol was not significant. Each of the three host factors significantly increased several virulence-related phenotypes in V. anguillarum, i.e. protease activity, flagellar motility, biofilm formation and exopolysaccharide production, whereas there was no effect on growth of the bacterium under these conditions. Furthermore, the host factors increased the expression of genes involved in these phenotypes, i.e. the metalloprotease empA, the flagellar transcriptional regulator fleQ, the flagellin gene flaA, the chemotaxis methyltransferase gene cheR, the exopolysaccharide biosynthesis gene wbfD and the exopolysaccharide export gene wza. Our results indicate that V. anguillarum uses host mucin, bile salts, and cholesterol as cues to promote the expression of several important virulence traits that enhance the success of transmission from one host to another.
authors.affiliation: Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Ghent, Belgium.
authors.forename: Xuan
authors.initials: X
authors.lastname: Li
authors.affiliation: Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Ghent, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Bossier
authors.affiliation: Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Ghent, Belgium.
authors.forename: Kristof
authors.initials: K
authors.lastname: Dierckens
authors.affiliation: Ecloserie marine de Gravelines, voie des Enrochements, 59820 Gravelines, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Laureau
authors.affiliation: Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Ghent, Belgium; Laboratory of Microbial Ecology and Technology, Ghent University, Ghent, Belgium. Electronic address: Tom.Defoirdt@UGent.be.
authors.forename: Tom
authors.initials: T
authors.lastname: Defoirdt
mesh_terms: D000818:Animals; D001492:Bass / Q000382:microbiology*; D001647:Bile Acids and Salts / Q000494:pharmacology*; D002784:Cholesterol / Q000494:pharmacology*; D005393:Fish Diseases / Q000382:microbiology; D005856:Germ-Free Life; D007814:Larva / Q000382:microbiology; D009077:Mucins / Q000494:pharmacology*; D010641:Phenotype; D014733:Vibrio / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D014735:Vibrio Infections / Q000382:microbiology / Q000662:veterinary; D014774:Virulence
chemical_list: D001647:Bile Acids and Salts; D009077:Mucins; D002784:Cholesterol
keywords: Bile salts; Cholesterol; Cue; Host–pathogen interaction; Mucin; Virulence