title: Characterization of role of the toxR gene in the physiology and pathogenicity of Vibrio alginolyticus.
abstract: toxR, a conserved virulence-associated gene in vibrios, is identified in Vibrio alginolyticus ZJ51-O, a pathogenic strain isolated from diseased fish. To reveal the role of ToxR in the pathogenicity of V. alginolyticus, a deletion mutant was constructed by allelic exchange. The mutant showed the same level of growth in trypticase soy broth (TSB) and iron-limiting condition, as the wild type strain. However, deletion of toxR severely reduced resistance against bile salts and the capability of biofilm formation. Outer-membrane protein (OMP) analysis showed that a 37-kD protein was absent and a 43-kD protein was decreased in the mutant. By MS/MS, the two proteins are identified as the homologues of OmpT and OmpN, respectively. These data suggest that ToxR might have enhanced the bile resistance and biofilm formation through modulating the production of OMP without affecting the ability of iron acquisition and the virulence to the fish via injection. These results indicate that ToxR may assist V. alginolyticus to colonize on the surface of the fish intestine which is crucial for the initiation of the infection, though it may not be involved in the proliferation of the bacteria in the host tissue.
authors.affiliation: The Key Laboratory of Marine Bio-resources Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences, West Xingang Road 164, Guangzhou, 510301, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Chen
authors.forename: Qing-bai
authors.initials: QB
authors.lastname: Wang
authors.forename: Zhu-Hong
authors.initials: ZH
authors.lastname: Liu
authors.forename: Jing-jing
authors.initials: JJ
authors.lastname: Zhao
authors.forename: Xiao
authors.initials: X
authors.lastname: Jiang
authors.forename: Hong-yan
authors.initials: HY
authors.lastname: Sun
authors.forename: Chun-hua
authors.initials: CH
authors.lastname: Ren
authors.forename: Chao-qun
authors.initials: CQ
authors.lastname: Hu
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005393:Fish Diseases / Q000382:microbiology*; D007501:Iron / Q000378:metabolism; D010473:Perciformes / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014735:Vibrio Infections / Q000382:microbiology / Q000662:veterinary*; D044149:Vibrio alginolyticus / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D014774:Virulence
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C066719:toxR protein, bacteria; D007501:Iron