is a major pig pathogen causing severe economic losses to the swine industry. This study aimed to analyze the genome of strain INT-01 isolated from a domestic pig in Korea. We found that the genome of strain INT-01 contains 2,092,054 bp, with a guanine (G) + cytosine (C) content of 41.
View Article and Find Full Text PDFLeuO plays the role of a master regulator in the cyclic-L-phenylalanine-L-proline (cFP)-dependent signaling pathway in Vibrio vulnificus. cFP, as shown through isothermal titration calorimetry analysis, binds specifically to the periplasmic domain of ToxR. Binding of cFP triggers a change in the cytoplasmic domain of ToxR, which then activates transcription of leuO encoding a LysR-type regulator.
View Article and Find Full Text PDF, an opportunistic human pathogen, produces cyclo-(l-Phe-l-Pro) (cFP), which serves as a signaling molecule controlling the ToxR-dependent expression of innate bacterial genes, and also as a virulence factor eliciting pathogenic effects on human cells by enhancing intracellular reactive oxygen species levels. We found that cFP facilitated the protection of against hydrogen peroxide. At a concentration of 1 mM, cFP enhanced the level of the transcriptional regulator RpoS, which in turn induced expression of , encoding hydroperoxidase I, an enzyme that detoxifies HO to overcome oxidative stress.
View Article and Find Full Text PDFThe recognition of pathogen-derived ligands by pattern recognition receptors activates the innate immune response, but the potential interaction of quorum-sensing (QS) signaling molecules with host anti-viral defenses remains largely unknown. Here we show that the Vibrio vulnificus QS molecule cyclo(Phe-Pro) (cFP) inhibits interferon (IFN)-β production by interfering with retinoic-acid-inducible gene-I (RIG-I) activation. Binding of cFP to the RIG-I 2CARD domain induces a conformational change in RIG-I, preventing the TRIM25-mediated ubiquitination to abrogate IFN production.
View Article and Find Full Text PDFVibrio vulnificus is a marine bacterium that causes human infections resulting in high mortality. This pathogen harbors five quorum-regulatory RNAs (Qrr1-5) that affect the expression of pathogenicity genes by modulating the expression of the master regulator SmcR. The qrr genes are activated by phosphorylated LuxO to different degrees; qrr2 is strongly activated; qrr3 and qrr5 are moderately activated, and qrr1 and qrr4 are marginally activated and are the only two that do not respond to cell density-dependent regulation.
View Article and Find Full Text PDFCyclo(phenylalanine-proline) is produced by various organisms such as animals, plants, bacteria and fungi. It has diverse biological functions including anti-fungal activity, anti-bacterial activity and molecular signalling. However, a few studies have demonstrated the effect of cyclo(phenylalanine-proline) on the mammalian cellular processes, such as cell growth and apoptosis.
View Article and Find Full Text PDFWe describe a novel insulin-degrading enzyme, SidC, that contributes to the proliferation of the human bacterial pathogen Vibrio vulnificus in a mouse model. SidC is phylogenetically distinct from other known insulin-degrading enzymes and is expressed and secreted specifically during host infection. Purified SidC causes a significant decrease in serum insulin levels and an increase in blood glucose levels in mice.
View Article and Find Full Text PDFCyclo(Phe-Pro) (cFP) is a secondary metabolite produced by certain bacteria and fungi. Although recent studies highlight the role of cFP in cell-to-cell communication by bacteria, its role in the context of the host immune response is poorly understood. In this study, we investigated the role of cFP produced by the human pathogen Vibrio vulnificus in the modulation of innate immune responses toward the pathogen.
View Article and Find Full Text PDFDiketopiperazine is produced by various organisms, including bacteria, fungi, and animals, and has been suggested as a novel signal molecule involved in the modulation of genes with various biological functions. Vibrio vulnificus, which causes septicemia in humans, produces cyclo(L-phenylalanine-L-proline) (cFP). To understand the biological roles of cFP, the effect of the compound on the expression of the total mRNA in V.
View Article and Find Full Text PDFThe gene vvpE, encoding the virulence factor elastase, is a member of the quorum-sensing regulon in Vibrio vulnificus and displays enhanced expression at high cell density. We observed that this gene was repressed under iron-rich conditions and that the repression was due to a Fur (ferric uptake regulator)-dependent repression of smcR, a gene encoding a quorum-sensing master regulator with similarity to luxR in Vibrio harveyi. A gel mobility shift assay and a footprinting experiment demonstrated that the Fur-iron complex binds directly to two regions upstream of smcR (-82 to -36 and -2 to +27, with respect to the transcription start site) with differing affinities.
View Article and Find Full Text PDFVibrio vulnificus is a halophilic marine pathogen associated with human diseases such as septicemia and serious wound infections. Genes vvsA and vvsB, which are co-transcribed and encode a member of the nonribosomal peptide synthase family, are required for vulnibactin biosynthesis in V. vulnificus.
View Article and Find Full Text PDFWe compared the gene expression among four clinical and five environmental V. vulnificus isolates, using a cDNA microarray containing 131 genes possibly associated with pathogenicity, transport, signal transduction, and gene regulations in the pathogen. cDNAs from total RNAs of these isolates were hybridized into the cDNA microarray using the cDNA of the wild-type strain MO6/24-O as a reference.
View Article and Find Full Text PDFVibrio vulnificus produces siderophores, lowmolecular- weight iron-chelating compounds, to obtain iron under conditions of iron deprivation. To identify genes associated with the biosynthesis of siderophore in V. vulnificus MO6-24/ O, we screened clones with mini-Tn5 random insertions for those showing decreased production of siderophore.
View Article and Find Full Text PDFVibrio vulnificus was found to produce a chemical that induced the expression of Vibrio fischeri lux genes. Electron spray ionization-mass spectrometry and 1H nuclear magnetic resonance analyses indicated that the compound was cyclo(L-Phe-L-Pro) (cFP). The compound was produced at a maximal level when cell cultures reached the onset of stationary phase.
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