Succinate dehydrogenase mutant of Listonella anguillarum protects rainbow trout against vibriosis

• Published in: Vaccine Vol. 33; no. 42; pp. 5572 - 5577
• Main Authors: Altinok, Ilhan, Capkin, Erol, Karsi, Attila
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 13.10.2015; Elsevier Limited
• Subjects: Allergy and Immunology; Animals; Bacterial Proteins - genetics; Bacterial Vaccines - immunology; Dehydrogenase; Fish; Fish Diseases - prevention & control; Freshwater; Freshwater fish; Genes; Immunization; Immunogenicity; Iron-Sulfur Proteins - genetics; Listonella - enzymology; Listonella - genetics; Listonella - pathogenicity; Listonella anguillarum; Oncorhynchus mykiss; Oncorhynchus mykiss - immunology; Oncorhynchus mykiss - microbiology; Plasmids; Rainbow trout; SDH; sdhB; Sequence Deletion; Succinate Dehydrogenase - genetics; Suicide; Sulfur; Survival; Vaccine; Vaccines; Vaccines, Attenuated - immunology; Vibrio Infections - prevention & control; Vibrio Infections - veterinary; Virulence; Listonella anguillarum; Vaccine; SDH; sdhB; Rainbow trout
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2015.09.003

Abstract Listonella anguillarum is a Gram-negative facultative anaerobic rod causing hemorrhagic septicemia in marine and rarely in freshwater fish. Succinate dehydrogenase (SDH) plays an important role in the tricarboxylic acid (TCA) cycle by oxidizing succinate to fumarate while reducing ubiquinone to ubiquinol. Recent studies indicate that central metabolic pathways, including the TCA cycle, contribute to bacterial virulence. However, the role of SDH in L. anguillarum virulence has not been studied. Here, we report in-frame deletion of the succinate dehydrogenase iron-sulfur protein (SDHB) and its role in L. anguillarum virulence in rainbow trout. To accomplish this goal, upstream and downstream regions of the L. anguillarum sdhB gene were amplified in-frame and cloned into a suicide plasmid. The chromosomal sdhB gene of L. anguillarum was deleted by homologous recombination. Virulence and immunogenicity of the L. anguillarum Δ sdhB mutant ( La Δ sdhB ) were determined in rainbow trout. Results show that La Δ sdhB was highly attenuated in rainbow trout, and fish immunized with La Δ sdhB displayed high relative survival rate after exposure to wild type L. anguillarum . These findings indicate SDH is important in L. anguillarum virulence in rainbow trout, and La Δ sdhB could be used as an immersion, oral, or injection vaccine to protect rainbow trout against vibriosis.