title: Role of RpoS in stress survival, synthesis of extracellular autoinducer 2, and virulence in Vibrio alginolyticus.
abstract: Vibrio alginolyticus, a marine bacterium, is an opportunistic pathogen capable of causing vibriosis with high mortality to fishes in the South China Sea. Stress resistance is very important for its survival in the natural environment and upon infection of the host. RpoS, an alternative sigma factor, is considered as an important regulator involved in stress response and virulence in many pathogens. In this study, the rpoS gene was cloned and characterized to evaluate the role of RpoS in V. alginolyticus. The predicted protein showed high identity with other reported rpoS gene products. The in-frame deleted mutation of rpoS in V. alginolyticus led to sensitivity of the strain to ethanol, hyperosmolarity, heat, and hydrogen peroxide challenges. Further studies showed that extracellular autoinducer 2 level, four of seven detected protease activities, and cytotoxicity of extracellular products were markedly decreased in the rpoS mutant compared with that in the wild-type strain. The results indicated that the global regulator RpoS was part of the regulatory networks of virulence and LuxS quorum sensing system.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Tian
authors.forename: Qiyao
authors.initials: Q
authors.lastname: Wang
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Yue
authors.initials: Y
authors.lastname: Ma
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Cao
authors.forename: Yuanxing
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D002681:China; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D015536:Down-Regulation; D000431:Ethanol / Q000494:pharmacology; D005399:Fishes; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006714:Homoserine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007783:Lactones; D050296:Microbial Viability; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D044149:Vibrio alginolyticus / Q000472:pathogenicity* / Q000502:physiology*; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D000431:Ethanol; D006714:Homoserine; D006861:Hydrogen Peroxide