Project description:Vibrio species are recognized for their role in food- and water-borne diseases in humans, fish, and aquatic invertebrates. We screened bacterial strains isolated from raw food shrimp for those that are bactericidal to Vibrio strains. Here we identify and characterize Aeromonas dhakensis strain A603 which shows robust bactericidal activity specifically towards Vibrio and related taxa but less potency toward other Gram-negative species. Using the A603 genome and genetic analysis, we show that two antibacterial mechanisms account for its vibriocidal activity -- a highly potent Type Six Secretion System (T6SS) and biosynthesis of a vibriocidal phenazine-like small molecule, named here as Ad-Phen. Further analysis indicates coregulation between Ad-Phen and a pore-forming T6SS effector TseC, which potentiates V. cholerae to killing by Ad-Phen.
Project description:World aquaculture production of the Pacific white shrimp (Litopenaeus vannamei) is estimated to account for 80% of the total shrimp produce worldwide. The global demand for shrimp has driven the industry to utilize and rely on semi-intensive and intensive shrimp systems. In the United States, Pacific white shrimp production can take place in semi-intensive earthen ponds, recirculating aquaculture systems (RAS), biofloc technology and green water. In this study, the effects of lowering dissolved oxygen conditions in outdoor green water tanks on global gene expression is examined. Tissue samples from the gill and intestine were collected for gene expression analysis via RNA sequencing. Among all comparisons, RNA sequencing revealed the up-regulation of a single gene: hydroxyacid oxidase 1 gene. The HOA1 gene was found to be 7-fold higher in the intestine sample at the medium aeration level compare to that of the high (control) level. The HAO1 gene, also known as glycolate oxidase 1 (GOX1) is a gene related to the 2-hydroxyacid oxidase enzyme that is part of the oxidoreductase family and plays a role in glyoxylate and dicarboxylate metabolism. The identification of a single differentially expressed gene across all analyzed samples suggests that Pacific white shrimp exposed to lowering dissolved oxygen set points does not induce global changes in gene expression at these levels.
2025-07-17 | GSE281217 | GEO
Project description:Genomic characterization of Vibrio species from shrimp farming
Project description:The phenomenon of trained immunity, which facilitates vaccine development for disease control, has been identified in shrimp; however, the mechanism remains elusive. In the present study, we found that histone H3K27 acetylation (H3K27ac) mediated by the lysine acetyltransferase KAT8 plays an important role in preventing white spot syndrome virus (WSSV) infection in the shrimp Marsupenaeus japonicus. We then successfully established a model of trained immunity via the use of UV-inactivated WSSV to explore the underlying mechanism(s) in shrimp. In UV-WSSV-trained shrimp, the glycolysis and tricarboxylic acid (TCA) cycle metabolic pathways were enhanced and acetyl-CoA concentrations were increased. As the acetyl group donor, acetyl-CoA promotes KAT8 activity to increase H3K27 acetylation. H3K27ac is deposited at the promoter region of the transcription factor Dorsal to facilitate its expression and then Dorsal promotes the expression of an interferon-like cytokine, Vago5, and antimicrobial peptides that act against WSSV infection. H3K27ac is also deposited at the promoter region of hexokinase 2 and isocitrate dehydrogenase, which positively regulates glycolysis and the TCA cycle in a feedforward manner. Our results reveal a novel mechanism of trained immunity induced by UV-WSSV in shrimp and provide a theoretical basis for the development of antiviral vaccines for disease control in shrimp aquaculture.
Project description:In aquatic invertebrates, the hemolymph functions as a conduit between the host and its environment, hence, maintaining hemolymph microbial homeostasis significantly influences disease pathogenesis. This study examined the critical role of the respiratory glycoprotein hemocyanin as a host factor in modulating hemolymph microbial composition in penaeid shrimp. Shrimp depleted of hemocyanin followed by Vibrio parahaemolyticus infection had a disruption in the niacinamide salvage pathway, which consequently increased total bacteria and relative abundance of the conditional pathogens Vibrio and Shewanella in the hemolymph. Moreover, in vivo knockdown of hemocyanin followed by niacinamide supplementation restored hemolymph microbial homeostasis, mitigating the competitive advantage of Vibrio. Overall, our data present novel insights into the pivotal role of niacinamide metabolism in modulating shrimp hemolymph microbial composition through hemocyanin.
Project description:Japanese flounder (Paralichthys olivaceus) is an economic important aquaculture fish that was susceptible to Vibrio anguillarum. To fully deciphered the molecular mechanisms underlying flounder host defense against V. anguillarum infection, we perform the micro-transcriptome analysis of founder spleen with and without V. anguillarum infection at 3 time points.
Project description:Vibrio parahaemolyticus is a Gram-negative bacterium commonly found in marine and estuarine environments. Acute hepatopancreatic necrosis disease (AHPND) caused by this bacterium is an ongoing problem among shrimp farming industries. V. parahaemolyticus proteins PirA and PirB have been determined to be major virulence factors that induce AHPND. In this study, Pacific white shrimp (Litopenaeus vannamei) were challenged with recombinant PirA and PirB by a reverse gavage method and then at 30 m, 1, 2, 4, and 6 h time points, the hepatopancreas of five individual shrimp were removed and placed into RNA later. We conducted RNA sequencing of the hepatopancreas samples from a no PirA/B control (n = 5) and PirA/B-treated shrimp at the different time intervals (n=5). We evaluated the different gene expression patterns between the time groups to the control with a focus on identifying differences in innate immune function.