Project description:Comparative proteomics to identify proteins found in the media of Vibrio parahaemolyticus RIMD 2210633 bacteria with an active T6SS2 compared to bacteria with inactive T6SS2. Bacteria with an active T6SS2 are Vibrio parahaemolyticus RIMD 2210633 inwhich hcp1 was deleted to inactivate T6SS1. T6SS2 inactive bacteria are the former strain with an additional deletion in hcp2. Both strains express TfoX from an arabinose-inducible plasmid to induce T6SS2 activity.
Project description:Vibrio parahaemolyticus is a Gram-negative marine bacterium. A limited population of the organisms causes acute gastroenteritis in humans. Almost all of the clinical V. parahaemolyticus isolates exhibit a beta-type hemolysis on Wagatsuma agar, known as the Kanagawa phenomenon (KP). KP is induced by the thermostable direct hemolysin (TDH) produced by the organism, and has been considered a crucial marker to distinguish pathogenic strains from non-pathogenic ones. Since 1996, so-called “pandemic clones”, the majority of which belong to serotype O3:K6, have caused worldwide outbreaks of gastroenteritis. In this study, we used a DNA microarray constructed based on the genome sequence of a pandemic V. parahaemolyticus strain RIMD2210633 to examin the genomic composition of 22 strains of V. parahaemolyticus, including both pathogenic (pandemic as well as non-pandemic) and non-pathogenic strains. Over 85% of the RIMD2210633 genes were conserved in all the strains tested. Many of variably present genes formed gene clusters on the genome of RIMD2210633 and were probably acquired through lateral gene transfer. At least 70 genes over 10 loci were specifically present in the pandemic strains when compared with any of the non-pandemic strains, suggesting that the difference between pandemic and non-pandemic strains is not due to a simple genetic event. Only the genes in the 80-kb pathogenicity island (Vp-PAI) on chromosome II, including two tdh genes and a set of genes for the Type III secretion system, were detected only in the KP-positive pathogenic strains. These results strongly suggest that acquisition of this Vp-PAI was crucial for the emergence of V. parahaemolyticus strains that are pathogenic for humans. Keywords: comparative genomic hybridization, CGH
Project description:Compare the secreted proteins of a wild-type Vibrio parahaemolyticus strain with those of a mutant in hcp2, rendering the T6SS2 inactive
Project description:Vibrio parahaemolyticus is the causative agent of food-borne gastroenteritis disease. Once consumed, human acid gastric fluid is perhaps one of the most important environmental stresses imposed on the bacterium. Herein, for the first time, we investigated Vibrio parahaemolyticus CHN25 response to artificial gastric fluid (AGF) stress by transcriptomic analysis. The bacterium at logarithmic growth phase (LGP) displayed lower survival rates than that at stationary growth phase (SGP) under a sub-lethal acid condition (pH 4.9). Transcriptome data revealed that 11.6% of the expressed genes in Vibrio parahaemolyticus CHN25 was up-regulated in LGP cells after exposed to AGF (pH 4.9) for 30 min, including those involved in sugar transport, nitrogen metabolism, energy production and protein biosynthesis, whereas 14.0% of the genes was down-regulated, such as ABC transporter and flagellar biosynthesis genes. In contrast, the AGF stress only elicited 3.4% of the genes from SGP cells, the majority of which were attenuated in expression. Moreover, the number of expressed regulator genes was also substantially reduced in SGP cells. Comparison of transcriptome profiles further revealed forty-one growth-phase independent genes in the AGF stress, however, half of which displayed distinct expression features between the two growth phases. Vibrio parahaemolyticus seemed to have evolved a number of molecular strategies for coping with the acid stress. The data here will facilitate future studies for environmental stresses and pathogenicity of the leading food-borne pathogen worldwide.
Project description:Vibrio parahaemolyticus is a Gram-negative marine bacterium. A limited population of the organisms causes acute gastroenteritis in humans. Almost all of the clinical V. parahaemolyticus isolates exhibit a beta-type hemolysis on Wagatsuma agar, known as the Kanagawa phenomenon (KP). KP is induced by the thermostable direct hemolysin (TDH) produced by the organism, and has been considered a crucial marker to distinguish pathogenic strains from non-pathogenic ones. Since 1996, so-called âpandemic clonesâ, the majority of which belong to serotype O3:K6, have caused worldwide outbreaks of gastroenteritis. In this study, we used a DNA microarray constructed based on the genome sequence of a pandemic V. parahaemolyticus strain RIMD2210633 to examin the genomic composition of 22 strains of V. parahaemolyticus, including both pathogenic (pandemic as well as non-pandemic) and non-pathogenic strains. Over 85% of the RIMD2210633 genes were conserved in all the strains tested. Many of variably present genes formed gene clusters on the genome of RIMD2210633 and were probably acquired through lateral gene transfer. At least 70 genes over 10 loci were specifically present in the pandemic strains when compared with any of the non-pandemic strains, suggesting that the difference between pandemic and non-pandemic strains is not due to a simple genetic event. Only the genes in the 80-kb pathogenicity island (Vp-PAI) on chromosome II, including two tdh genes and a set of genes for the Type III secretion system, were detected only in the KP-positive pathogenic strains. These results strongly suggest that acquisition of this Vp-PAI was crucial for the emergence of V. parahaemolyticus strains that are pathogenic for humans. Keywords: comparative genomic hybridization, CGH Total 66 test samples were analyzed. Genomic DNA from each test strain and a reference strain (RIMD2210633) were labeled with Cy3 and Cy5, respectively, and were cohybridized on a single array. Labeling and hybridization were performed three times independently.
Project description:Vibrio parahaemolyticus is the causative agent of food-borne gastroenteritis disease. Once consumed, human acid gastric fluid is perhaps one of the most important environmental stresses imposed on the bacterium. Herein, for the first time, we investigated Vibrio parahaemolyticus CHN25 response to artificial gastric fluid (AGF) stress by transcriptomic analysis. The bacterium at logarithmic growth phase (LGP) displayed lower survival rates than that at stationary growth phase (SGP) under a sub-lethal acid condition (pH 4.9). Transcriptome data revealed that 11.6% of the expressed genes in Vibrio parahaemolyticus CHN25 was up-regulated in LGP cells after exposed to AGF (pH 4.9) for 30 min, including those involved in sugar transport, nitrogen metabolism, energy production and protein biosynthesis, whereas 14.0% of the genes was down-regulated, such as ABC transporter and flagellar biosynthesis genes. In contrast, the AGF stress only elicited 3.4% of the genes from SGP cells, the majority of which were attenuated in expression. Moreover, the number of expressed regulator genes was also substantially reduced in SGP cells. Comparison of transcriptome profiles further revealed forty-one growth-phase independent genes in the AGF stress, however, half of which displayed distinct expression features between the two growth phases. Vibrio parahaemolyticus seemed to have evolved a number of molecular strategies for coping with the acid stress. The data here will facilitate future studies for environmental stresses and pathogenicity of the leading food-borne pathogen worldwide. When V.parahemolyticus CHN25 grown to log phase and stationary phase at 37°C in TSB-3% NaCl, different cultures were subsequently exposed to artificial gastric fluid at 37°C for 30 min. Two independent experiments were performed at each phase for microarray expreriments.
Project description:In order to gain a better understanding of the impact of Vibrio parahaemolyticus infection on genetic regulation of Litopenaeus vannamei,we performed a transcriptome analysis in the hepatopancreas of Litopenaeus vannamei challenged with Vibrio parahaemolyticus, using the Illumina HiSeq 2500 platform.
Project description:Vibrio parahaemolyticus an emerging pathogen that is a causative agent of foodborne gastroenteritis when raw or undercooked seafood is consumed. Previous microarray data using a Vibrio parahaemolyticus RIMD2210633 chip has shown the master quorum-sensing regulator OpaR controls virulence, type III and type VI secretion systems, and flagellar and capsule production genes. In a parallel study, RNA-Seq was used to comparatively study the transcriptome changes of wild type Vibrio parahaemolyticus BB22 and a ΔopaR strain directly. Differences in mRNA expression were analyzed using next generation Illumina sequencing and bioinformatics techniques to align and count reads. A comparison with the previous microarray data showed good correlation between the shared genes. The RNA-Seq offered an insight into control of genes specific to the Vibrio parahaemolyticus BB22 strain as well as a new look at the sRNAs that are expressed. Eleven transcriptional regulators with greater than 4 fold regulation in the previous microarray study and 2 fold regulation in the RNA-Seq analysis, were chosen to validate the data using qRT-PCR and further characterized with electrophoretic mobility shift assays (EMSAs) to determine if they are direct targets of OpaR. The transcription factors chosen play key roles in virulence, surface motility, cell to cell interactions, and cell surface characteristics. One small RNA was identified in the RNA-Seq data to be quorum-sensing controlled and unidentified by other programs. The RNA-Seq data has aided in understanding and elucidating the hierarchy of quorum-sensing control of OpaR in Vibrio parahaemolyticus. The wild type Vibrio parahaemolyticus BB22 strain LM5312 and an opaR deletion strain LM5674 were analyzed for mRNA expression using RNA-Seq.
Project description:Vibrio parahaemolyticus is a Gram-negative marine bacterium. Strain RIMD 2210633, the wild type strain of the organism, causes acute gastroenteritis in humans. Human intestinal factor bile often affects the global gene regulation in some species of enteropathogenic bacteria. To determine the genes in V. parahaemolyticus that respond to bile, we investigated the differences in the transcriptomes of the wild type strain and the vtrA-null strain grown in Luria-Bertani medium cultivated with or without 0.04% crude bile. The vtrA gene encodes the previously identified T3SS2 regulator. Our goal is to demonstrate bile regulon controlled by VtrA in V. parahaemolyticus.
Project description:Vibrio parahaemolyticus an emerging pathogen that is a causative agent of foodborne gastroenteritis when raw or undercooked seafood is consumed. Previous microarray data using a Vibrio parahaemolyticus RIMD2210633 chip has shown the master quorum-sensing regulator OpaR controls virulence, type III and type VI secretion systems, and flagellar and capsule production genes. In a parallel study, RNA-Seq was used to comparatively study the transcriptome changes of wild type Vibrio parahaemolyticus BB22 and a ΔopaR strain directly. Differences in mRNA expression were analyzed using next generation Illumina sequencing and bioinformatics techniques to align and count reads. A comparison with the previous microarray data showed good correlation between the shared genes. The RNA-Seq offered an insight into control of genes specific to the Vibrio parahaemolyticus BB22 strain as well as a new look at the sRNAs that are expressed. Eleven transcriptional regulators with greater than 4 fold regulation in the previous microarray study and 2 fold regulation in the RNA-Seq analysis, were chosen to validate the data using qRT-PCR and further characterized with electrophoretic mobility shift assays (EMSAs) to determine if they are direct targets of OpaR. The transcription factors chosen play key roles in virulence, surface motility, cell to cell interactions, and cell surface characteristics. One small RNA was identified in the RNA-Seq data to be quorum-sensing controlled and unidentified by other programs. The RNA-Seq data has aided in understanding and elucidating the hierarchy of quorum-sensing control of OpaR in Vibrio parahaemolyticus.