Complete genome sequence of Vibrio parahaemolyticus CHN25 and transcriptomic analysis of cold shock proteins of VpaCspA and VpaCspD in the adaptation of low temperature growth
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ABSTRACT: To investigate low-temperature tolerance of the bacterium, three in-frame gene deletion mutants of VpacspA and VpacspD were constructed using homologous recombination method. When compared to the wild type strain, the growth of ΔVpacspA mutant was strongly repressed at 10 0C, whereas the deletion of VpacspD gene greatly activated the bacterium growth at the low temperature. Transcriptome data revealed that 12.4% of the expressed genes in V. parahaemolyticus CHN25 was significantly changed in ΔVpacspA mutant grown at 10 0C, including those involved in amino acid degradation, ATP-binding cassette (ABC) transporters, secretion systems, sulfur and glycerophospholipid metabolisms, whereas the low temperature elicited 10.0% of the genes from ΔVpacspD mutant, such as phosphotransferase system, nitrogen and amino acid metabolisms. Moreover, the major changed metabolic pathways in dual-gene deletion mutant (ΔVpacspAD) differed radically from those in single-gene mutants. Comparison of transcriptome profiles further revealed a number of differentially expressed genes shared among the three mutants, as well as regulators specifically, coordinately and or antagonistically regulating in the adaptation of V. parahaemolyticus CHN25 to the low-temperature growth. mRNA profiles of mid-log phase WT(G), ΔVpacspA, ΔVpacspD and ΔVpacspAD at 10 °C were generated by deep sequencing using Illumina HiSeq 2500
Project description:To investigate low-temperature tolerance of the bacterium, three in-frame gene deletion mutants of VpacspA and VpacspD were constructed using homologous recombination method. When compared to the wild type strain, the growth of ΔVpacspA mutant was strongly repressed at 10 0C, whereas the deletion of VpacspD gene greatly activated the bacterium growth at the low temperature. Transcriptome data revealed that 12.4% of the expressed genes in V. parahaemolyticus CHN25 was significantly changed in ΔVpacspA mutant grown at 10 0C, including those involved in amino acid degradation, ATP-binding cassette (ABC) transporters, secretion systems, sulfur and glycerophospholipid metabolisms, whereas the low temperature elicited 10.0% of the genes from ΔVpacspD mutant, such as phosphotransferase system, nitrogen and amino acid metabolisms. Moreover, the major changed metabolic pathways in dual-gene deletion mutant (ΔVpacspAD) differed radically from those in single-gene mutants. Comparison of transcriptome profiles further revealed a number of differentially expressed genes shared among the three mutants, as well as regulators specifically, coordinately and or antagonistically regulating in the adaptation of V. parahaemolyticus CHN25 to the low-temperature growth.
Project description:Vibrio parahaemolyticus is the leading bacterial cause for seafood-related gastroenteritis worldwide. As an intestinal pathogen, V. parahaemolyticus competes with other commensal bacteria for the same pool of nutrients. The major source of nutrition for intestinal bacteria is intestinal mucus. We wanted to determine the expression profile of wild-type V. parahaemolyticus in mouse intestinal mucus and then perform a differential expression analysis in a ∆luxO deletion mutant, in which the high cell density quorum sensing regulator OpaR is constitutively expressed and low cell density regulator AphA is repressed.
Project description:Vibrio parahaemolyticus is a Gram-negative marine bacterium. A limited population of the organisms causes acute gastroenteritis in humans. Vibrio parahaemolyticus wild type strain RIMD 2210633 compared with the mutants of VtrA and VtrB have a winged helix-turn-helix DNA binding motif that genes encoded on pathogenicity island loci, at OD600=1.0 in Luria-Bertani containing medium 0.5 % NaCl at 37˚C. Our goal is to determine the VtrA or VtrB regulon.
Project description:Vibrio parahaemolyticus is a Gram-negative marine bacterium. A limited population of the organisms causes acute gastroenteritis in humans. Vibrio parahaemolyticus wild type strain RIMD 2210633 compared with the mutants of VtrA and VtrB have a winged helix-turn-helix DNA binding motif that genes encoded on pathogenicity island loci, at OD600=1.0 in Luria-Bertani containing medium 0.5 % NaCl at 37˚C. Our goal is to determine the VtrA or VtrB regulon. Cohybridized wild type versus vtrA or vtrB mutants on a single array. Biological replicates: three of wild type, three of vtrA mutants and three of vtrB mutants were independently grown and harvested.
Project description:Vibrio (V.) parahaemolyticus is the leading cause of seafood borne gastro-intestinal infections in humans worldwide. It is widely found in marine environments and is isolated frequently from seawater, estuarine waters, sediments and raw or insufficiently cooked seafood. Within the food chain, V. parahaemolyticus encounters different temperature conditions that might alter the metabolism and pathogenicity of the bacterium. In this study, we performed gene expression profiling of V. parahaemolyticus RIMD 2210633 after exposure to 4°C, 15°C, 20°C, 37°C and 42°C to describe the cold and heat shock response. Analysis of transcriptomics data resulted in differential expression of 19 genes at 20°C, 193 genes at 4°C, 625 genes at 42°C and 639 genes at 15°C. Thus the highest portion of significantly expressed genes was observed at 15°C and 42°C with 13.3% and 13%, respectively. Genes of many functional categories were highly regulated even at lower temperatures. Our results showed that virulence associated genes (tdh1, tdh2, toxR, toxS, vopC, T6SS1, T6SS2) remained largely unaffected by heat or cold stresses. Along with folding and temperature shock depending systems, an overall temperature depended regulation of expression could be shown. Particularly the energy metabolism was affected most by changed temperatures. Whole-genome gene expression studies of food related pathogens such as V. parahaemolyticus reveal how these pathogens react to stress impacts for prediction of its behaviour under conditions like storage and transport.
Project description:Vibrio parahaemolyticus is the leading bacterial cause for seafood-related gastroenteritis worldwide. As an intestinal pathogen, V. parahaemolyticus competes with other commensal bacteria for the same pool of nutrients. The major source of nutrition for intestinal bacteria is intestinal mucus. We wanted to determine the expression profile of wild-type V. parahaemolyticus in mouse intestinal mucus and then perform a differential expression analysis in a ∆rpoN deletion mutant.
Project description:Vibrio (V.) parahaemolyticus is the leading cause of seafood borne gastro-intestinal infections in humans worldwide. It is widely found in marine environments and is isolated frequently from seawater, estuarine waters, sediments and raw or insufficiently cooked seafood. Within the food chain, V. parahaemolyticus encounters different temperature conditions that might alter the metabolism and pathogenicity of the bacterium. In this study, we performed gene expression profiling of V. parahaemolyticus RIMD 2210633 after exposure to 4°C, 15°C, 20°C, 37°C and 42°C to describe the cold and heat shock response. Analysis of transcriptomics data resulted in differential expression of 19 genes at 20°C, 193 genes at 4°C, 625 genes at 42°C and 639 genes at 15°C. Thus the highest portion of significantly expressed genes was observed at 15°C and 42°C with 13.3% and 13%, respectively. Genes of many functional categories were highly regulated even at lower temperatures. Our results showed that virulence associated genes (tdh1, tdh2, toxR, toxS, vopC, T6SS1, T6SS2) remained largely unaffected by heat or cold stresses. Along with folding and temperature shock depending systems, an overall temperature depended regulation of expression could be shown. Particularly the energy metabolism was affected most by changed temperatures. Whole-genome gene expression studies of food related pathogens such as V. parahaemolyticus reveal how these pathogens react to stress impacts for prediction of its behaviour under conditions like storage and transport. Temperature induced gene expression was detected in total bacterial RNA of V. parahaemolyticus. Five different temperatures (4°C, 15°C, 20°C, 37°C, 42°C) were used in at least 3 biological replicates (4 replicates for 37°C). Gene expression at 37°C was used for normalization.
Project description:Table grapes cv. Cardinal are highly perishable and their quality deteriorates during postharvest storage at low temperature mainly because of sensitivity to fungal decay and senescence of rachis. The application of a 3-day CO2 treatment with 20 kPa CO2 at 0C reduced total decay and retained fruit quality in early and late-harvested table grapes during postharvest storage. In order to study the transcriptional responsiveness of table grapes to low temperature and high CO2 levels in the first stage of storage and how the maturity stage affect these changes, we have performed a comparative large-scale transcriptional analysis. In the first stage of storage, low temperature led to a significantly intense change in grape skin transcriptome irrespective of fruit maturity, although there were different changes within each stage. In the case of CO2 treated samples, in comparison to fruit at time zero, only slight differences were observed. Functional enrichment analysis revealed that major modifications in the transcriptome profile of early- and late-harvested grapes stored at 0C are linked to biotic and abiotic stress-responsive terms. However, in both cases there is a specific reprogramming of the transcriptome during the first stage of storage at 0C in order to withstand the cold stress. Thus, genes involved in gluconeogenesis, photosynthesis, mRNA translation and lipid transport were up-regulated in the case of early-harvested grapes, and genes related to protein folding stability and intracellular membrane trafficking in late-harvested grapes. The beneficial effect of high CO2 treatment maintaining table grape quality seems to be an active process requiring the induction of several transcription factors and kinases in early-harvested grapes, and the activation of processes associated to the maintenance of energy in late-harvested grapes.
Project description:ABA deficiency reduced low temperature responses via disturbing stability of chloro-plast ultrastructure, modifying the starch and sucrose metabolisms, and affecting an-tioxidant enzyme activities in barley.
Project description:The two-component system CBO0366/CBO0365 was recently demonstrated to have a role in cold tolerance of Group I Clostridium botulinum ATCC 3502. The mechanisms under its control, ultimately resulting in increased sensitivity to low temperature, are unknown. A transcriptomic analysis with DNA microarrays was performed to identify the differences in global gene expression patterns of the wild-type ATCC 3502 and a derivative mutant with insertionally inactivated cbo0365 at 37 M-BM-0C and 15 M-BM-0C. Altogether 150 or 141 chromosomal CDSs were found to be differently expressed in the cbo0365 mutant at 37 M-BM-0C or 15 M-BM-0C, respectively, and thus considered to be under direct or indirect transcriptional control of the response regulator CBO0365. Of the differentially-expressed CDSs, expression of 141 CDSs was similarly affected at both temperatures investigated, suggesting that the putative CBO0365 regulon was practically not affected by temperature. The regulon involved genes related to acetone-butanol-ethanol (ABE) fermentation, motility, to arsenic resistance, and phosphate uptake and transport. Deteriorated growth at 17 M-BM-0C was observed for mutants with disrupted ABE fermentation pathway components (crt, bdh and ctfA), arsenic detoxifying machinery components (arsC and arsR), or phosphate uptake mechanism components (phoT), suggesting roles for these mechanisms in cold tolerance of Group I C. botulinum. Electrophoretic mobility shift assays showed recombinant CBO0365 to bind to the promoter regions of crt, arsR, and phoT, as well as to the promoter region of its own operon, suggesting direct DNA-binding transcriptional activation or repression as means for CBO0365 in regulating these operons. The results provide insight to the mechanisms Group I C. botulinum utilize in coping with cold. C. botulinum ATCC 3502 cbo0365 mutant vs. wild type; 3 replicates of each strain; growth at 37C in TPGY broth batch culture and subjected to cold shock to 15C; sampling at mid-log growth phase before cold shock, and 1 h after temperature downshift to 15C (= 2 time points). Dye-swapped hybridization.