title: Regulation of Vibrio alginolyticus virulence by the LuxS quorum-sensing system.
abstract: Quorum sensing (QS) is a bacterial intercommunication system that controls the expression of multiple genes in response to population density. The LuxS QS system regulates the expression of several virulence factors in a wide variety of pathogenic bacteria. LuxS has been characterized to be responsible for producing a type of autoinducer, AI-2, which stimulates the expression of the luciferase operon in Vibrio harveyi. Vibrio alginolyticus is established as an opportunistic pathogen of several marine animals, and its LuxS QS system remains undefined. To investigate the pathogenic role of luxS in V. alginolyticus, the luxS mutants of both the standard strain ATCC 33787 and a fish-clinical isolate MVP01, named MYJS and MYJM, respectively, were constructed. The mutation resulted in reduced lethality to Pagrus major. Intraperitoneal LD(50) of MYJS and MYJM increased by 15- and 93-fold, respectively. The two luxS mutants exhibited a lower growth rate and defective flagellar biosynthesis. They also showed a significant decrease in protease production and an increase in both extracellular polysaccharide production and biofilm development. The results suggest that the LuxS QS system plays an important role in regulating the expression of virulence factors in V. alginolyticus.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Ye
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: Q
authors.initials: Q
authors.lastname: Liu
authors.forename: D L
authors.initials: DL
authors.lastname: Zhao
authors.forename: Q Y
authors.initials: QY
authors.lastname: Wang
authors.forename: Y X
authors.initials: YX
authors.lastname: Zhang
mesh_terms: D000818:Animals; D033381:Anomura / Q000382:microbiology; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D018441:Biofilms / Q000254:growth & development; D013437:Carbon-Sulfur Lyases / Q000235:genetics / Q000502:physiology*; D004926:Escherichia coli / Q000472:pathogenicity; D005407:Flagella / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D006714:Homoserine / Q000031:analogs & derivatives / Q000032:analysis / Q000096:biosynthesis; D007783:Lactones / Q000032:analysis; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010447:Peptide Hydrolases / Q000032:analysis / Q000096:biosynthesis; D011135:Polysaccharides, Bacterial / Q000032:analysis / Q000096:biosynthesis; D053038:Quorum Sensing / Q000502:physiology*; D013997:Time Factors; D014733:Vibrio / Q000472:pathogenicity*; D044149:Vibrio alginolyticus / Q000254:growth & development / Q000472:pathogenicity; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D011135:Polysaccharides, Bacterial; D006714:Homoserine; D010447:Peptide Hydrolases; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria