Project description:Vibrio vulnificus causes severe necrotizing wound infections and life-threatening foodborne infections. While clinical isolates of V. vulnificus are well-established as human pathogens, the pathogenic mechanisms underlying the virulence of food-derived isolates, particularly in the case of wound infections, remain poorly understood. This study aimed to elucidate the pathogenic mechanisms of a highly virulent, seafood-derived V. vulnificus isolate. A molecular survey of 28 V. vulnificus isolates from Shenzhen identified four MARTX toxin types, with the D-type predominating (36%). We characterized a representative shrimp-derived isolate, Vv3, which carries a chromosomal D-type MARTX with an ACD-MCF-ABH-MCF effector architecture. Using a newly established mouse wound infection model, Vv3 induced 100% mortality within 12 hours, with high bacterial loads detected systemically. Pathological analysis revealed severe tissue damage at the infection site, marked by muscle necrosis, and significant distal organ damage. Strikingly, flow cytometry analysis of splenocytes showed a significant depletion of macrophages and lymphocytes, rather than a classic cytokine storm, which was supported by transcriptomic data. To dissect the molecular drivers underlying the pathogenicity of food-derived V. vulnificus, we generated isogenic toxin mutants. In vitro assays demonstrated that the MARTX toxin was the primary mediator of rapid cell death in both macrophages and epithelial cells. Deletion of the GD-rich repeat domain in the MARTX toxin (ΔrtxA-GD) significantly reduced cytotoxicity and allowed cells to maintain their morphology, while deletion of hemolysin (ΔvvhA) had a minor effect. Critically, In vivo mice wound infections indicated that MARTX-deficient mutants with or without deletion of vvhA is unable to cause mortality in mice. These results establish that the D-type MARTX toxin is the dominant virulence determinant in this foodborne isolate, driving mortality through a direct destruction of host cells. This study highlights the severe risk posed by foodborne V. vulnificus in wound exposures and informs that the GD-rich region serves as a potential target for intervention against V. vulnificus infection.
Project description:Vibrio vulnificus is an foodborne pathogen that can cause gastroenteritis and septicemia in humans. V. vulnificus secretes a multifunctional autoprocessing repeats-in-toxin (MARTX) toxin as an essential virulence factor to cause disease. MARTX toxins are pore-forming toxins that translocate multiple functionally independent effector domains into a target cell. MARTX toxins of V. vulnificus can contain anywhere from 3 to 5 of the 10 identified effector domains and strains with different effector repertories having varying virulence potential. The goal of this study was to compare how different effector combinations from an F-type MARTX toxin differentially remodel the transcriptional response of human intestinal epithelial cells (IECs). F-type MARTX toxins contain five effector domains – the actin crosslinking domain (ACD), two copies the makes caterpillar floppy-like domain (MCF), and alpha-beta hydrolase (ABH) domain, and the Ras/Rap1 specific endopeptidase (RRSP). Cultured human IECs were treated with V. vulnificus or strains modified to secrete a toxin with only ACD, ACD with MCF-ABH, ACD with RRSP, or no active effectors. We demonstrate that when no active effectors are present, the bacterium induces minimal changes in the transcriptional profile of IECs. However, the strains containing different effector combinations each uniquely remodeled the transcriptional profile of IECs. These data provide insight into how V. vulnificus strains with varying effector combinations can differentially regulate the host cell response to cause disease.
2021-11-21 | GSE189194 | GEO
Project description:Study of the foodborne tetracycline-resistant Vibrio spp. isolates from China
Project description:Small octopus is one of the major source for V. vulnificus outbreak among aquatic products in Northeast Asian due to improperly cooking and wound infection by mishandling. However, there is no report on whole genome sequence of V. vulnificus isolated from contaminated surf clam, thus no information is available for major virulence factors about V. vulnificus obtained from small octopus. Therefore, the analysis of transcriptome of isolated V. vulnificus from products are necessary to investigate potential risk of foodborne illness by contaminated products.
2017-07-11 | GSE101055 | GEO
Project description:2011-2023 Human and foodborne Vibrio vulnificus genomes in Shenzhen,China
Project description:Vibriosis caused by Vibrio vulnificus on eels represents an important threat for this specie under culture conditions. Development of new transcriptomic tools is essential to increase the knowledge of eel biology, that nowadays is scarcer. Therefore, using previous results obtained by 454 sequencing of the eel immune-enriched transcriptome, an eel-specific custom microarray have been designed. Gills transcriptomic pattern were analyzed as a principal portal of entry for pathogens in fish after 1h of bath infection with Vibrio vulnificus to describe gill immune response. Moreover, two different strains were used, vibro vulnificus wild type (R99) and rtx double mutant (CT285), to asses the virulence of these pathogen caused by MARTX.
Project description:In order to analyze the transcripts of Arabidopsis thaliana (Col-0) and Vibrio vulnificus MO6-24/O simultaneously, Vibrio vulnificus MO6-24/O was infiltrated onto Arabidopsis leaves and then leaves were harvested at 0, 3, 6, 12, 24 and 48 h post-infiltration. A total of 31, 128, 303, 219 and 130 differentially expressed genes (DEGs) of Vibrio were up- and down-regulated at 3, 6, 12, 24 and 48 h post-infiltration (hpi). Meanwhile, differentially expressed genes (DEGs) were monitored at 3, 6, 12, 24 and 48 h post-infiltration. A total of 2,097, 1,839, 1,220, 1,170 and 1,383 genes were characterized at each time points in Arabidopsis. Our data clearly indicate that total transcripts of the marine bacterial pathogen V. vulnificus MO6-24/O are detected and analyzed in plant Arabidopsis and two organisms were inter-communicated at the same time under favorable conditions.