Virulence of Vibrio harveyi ORM4 towards the European abalone Haliotis tuberculata involves both quorum sensing and a type III secretion system
Autor: | Albane Jouault, Javid Kavousi, Alexis Bazire, Alizée Le Ferrand, Adeline Bidault, Sahar El Fekih, Christine Paillard, Amandine Morot, Vianney Pichereau, François Delavat, Alain Dufour |
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Rok vydání: | 2021 |
Předmět: |
0303 health sciences
biology 030306 microbiology Vibrio harveyi Biofilm Virulence biology.organism_classification Microbiology Vibrio Type three secretion system 03 medical and health sciences Quorum sensing Gene cluster bacteria 14. Life underwater Pathogen Ecology Evolution Behavior and Systematics 030304 developmental biology |
Zdroj: | Environmental Microbiology. 23:5273-5288 |
ISSN: | 1462-2920 1462-2912 |
Popis: | Environmental Vibrio strains represent a major threat in aquaculture, but the understanding of their virulence mechanisms heavily relies on the transposition of knowledge from human-pathogen vibrios. Here, the genetic bases of the virulence of Vibrio harveyi ORM4 toward the European abalone Haliotis tuberculata were characterized. We demonstrated that luxO, encoding a major regulator of the quorum sensing system, is crucial for the virulence of this strain, and that its deletion leads to a decrease in swimming motility, biofilm formation, and exopolysaccharide production. Furthermore, the biofilm formation by V. harveyi ORM4 was increased by abalone serum, which required LuxO. The absence of LuxO in V. harveyi ORM4 yielded opposite phenotypes compared with other Vibrio species including V. campbellii (still frequently named V. harveyi). In addition, we report a full Type III Secretion System (T3SS) gene cluster in the V. harveyi ORM4 genome. LuxO was shown to negatively regulate the promoter activity of exsA, encoding the major regulator of the T3SS genes, and the deletion of exsA abolished the virulence of V. harveyi ORM4. These results unveil virulence mechanisms set up by this environmentally important bacterial pathogen, and pave the way for a better molecular understanding of the regulation of its pathogenicity. This article is protected by copyright. All rights reserved. |
Databáze: | OpenAIRE |
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