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.
2024-07-05 | GSE270023 | GEO
Project description:Genomic characterization of Vibrio species from shrimp farming
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.
Project description:Acute hepatopancreatic necrosis disease (AHPND) is a shrimp farming disease, caused by a pathogenic Vibrio parahaemolyticus carrying a plasmid encoding Vp_PirAB-like toxin (VpAHPND). Whiteleg shrimp, Litopenaeus vannamei were fed food pellets containing formalin-killed VpAHPND (FKC-VpAHPND) to select for toxin resistance. To identify genes associated with Vp_PirAB-like toxin resistance, total RNA was sequenced to identify differentially expressed genes (DEGs) in the stomach and hepatopancreas among surviving shrimp (sur-FKC), AHPND-infected shrimp (Vp-inf) and normal shrimp (control). From a total of 79,591 genes, 194 and 224 DEGs were identified in the stomach and hepatopancreas transcriptomes, respectfully. The expressions of DEGs were validated by qPCR of ten genes. Only one gene, a gene homologous to L vannamei anti-lipopolysaccharide factor AV-R isoform (LvALF AV-R), was expressed significantly more strongly in sur-FKC than in the other groups. The association of LvALF AV-R expression and toxin resistance was affirmed from the surviving shrimp in a second-trial of FKC-VpAHPND feeding. These results suggest that LvALF AV-R may be involved in shrimp defense mechanisms against Vp_PirAB-like toxin virulence.
