Similar Datasets
Project description:Vibrio campbellii is a gram-negative bacterial pathogen that is both free-living and a pathogen of marine organisms and exhibits swimming motility via a single, polar flagellum. Swimming motility is a critical virulence factor in V. campbellii pathogenesis, and disruption of the flagellar motor significantly decreases host mortality. However, while V. campbelli encodes homologs of flagellar and chemotaxis genes conserved by other members of the Vibrionaceae, the regulatory network governing these genes have not been explored. We systematically deleted all 63 known flagellar and chemotaxis genes in V. campbellii and examined their effects on motility compared to their homologs in other Vibrios. We specifically focused on assessing the roles of the core flagellar regulators of the flagellar regulatory hierarchy established in other Vibrios: rpoN, flrA, flrC, and fliA. Although V. campbellii transcription of flagellar and chemotaxis genes is governed by a multi-tiered regulatory hierarchy similar to other Vibrios, we observed two critical differences: the σ54-dependent regulator FlrA is dispensable for motility, and Class II gene expression is independent of σ54 regulation. Our genetic and phenotypic dissection of the V. campbellii flagellar regulatory network highlights the differences that have evolved in flagellar regulation across the Vibrionaceae.
2021-07-26 | GSE167483 | GEO
Project description:Members of the Vibrionaceae family are often found associated with chitin-containing organisms and they are thought to play a major role in chitin degradation. The purpose of the present study was to determine how chitin affected the transcriptome and metabolome of two bioactive Vibrionaceae strains, Vibrio corallilyticus and Photobacterium galatheae. We focused on chitin degradation genes and secondary metabolites based on the assumption that these molecules in nature confer an advantage to the producer. Growth on chitin caused up-regulation of genes related to chitin metabolism and of genes potentially involved in host colonization and/or infection. The expression of genes involved in secondary metabolism was also significantly affected by growth on chitin, in one case being thirty-four folds upregulated. This was reflected in the metabolome, where the antibiotics andrimid and holomycin were produced in higher amounts on chitin. Interestingly, in cultures of P. galatheae grown on chitin we detected high amounts of the biogenic amine phenylethylamine. Overall, these results suggest that both V. coralliilyticus and P. galatheae have a specific lifestyle for growth on chitin, and that the secondary metabolites they produce are likely to play a crucial role during chitin colonization.
2016-12-01 | GSE80782 | GEO
Project description:Members of the Vibrionaceae family are often found associated with chitin-containing organisms and they are thought to play a major role in chitin degradation. The purpose of the present study was to determine how chitin affected the transcriptome and metabolome of two bioactive Vibrionaceae strains, Vibrio corallilyticus and Photobacterium galatheae. We focused on chitin degradation genes and secondary metabolites based on the assumption that these molecules in nature confer an advantage to the producer. Growth on chitin caused up-regulation of genes related to chitin metabolism and of genes potentially involved in host colonization and/or infection. The expression of genes involved in secondary metabolism was also significantly affected by growth on chitin, in one case being thirty-four folds upregulated. This was reflected in the metabolome, where the antibiotics andrimid and holomycin were produced in higher amounts on chitin. Interestingly, in cultures of P. galatheae grown on chitin we detected high amounts of the biogenic amine phenylethylamine. Overall, these results suggest that both V. coralliilyticus and P. galatheae have a specific lifestyle for growth on chitin, and that the secondary metabolites they produce are likely to play a crucial role during chitin colonization.
2016-12-01 | GSE80781 | GEO
Project description:Genome mining of pigmented Pseudoalteromonas has revealed a large potential for production of bioactive compounds, both hydrolytic enzymes and secondary metabolites and the purpose of the present study was to explore this bioactivity potential in a potent antibiotic and enzyme producer, Pseudoalteromonas rubra strain S4059. Proteomic analyses indicated that a highly efficient chitin degradation machinery was present in the red-pigmented P. rubra S4059 when grown on chitin. Four GH18 chitinases and two GH20 hexosaminidases were significantly upregulated by chitin. GH19 chitinase which is not common in bacteria is consistently found in pigmented Pseudoalteromonas and in S4059 it was only detected when the bacterium was grown on chitin. To explore the possible role of GH19 in pigmented Pseudoalteromonas, we deleted the GH19 chitinase and compared a range of phenotypes in the mutant and wild type. Neither, the chitin degrading ability or the biofilm forming capacity was affected by GH19 deletion. In some Vibrionaceae, the secondary metabolome is significantly affected by growth on chitin as compared to simpler carbon sources. The secondary metabolites produced by S4059 and the GH19 mutant were xxx start by chitin/mannose – then the mutant. not altered by the absence of the gene, indicating that chitin utilization may not directly influence the production of secondary metabolites as has been observed in some Vibrionaceae. Metabolome analysis reveal that growth on chitin XX. In summary,
2021-03-11 | PXD023249 | Pride
Project description:Bacterial outer-membrane vesicles (OMVs) and the cargo they carry are increasingly recognized as a means of communication between microbial symbionts and the cells of their host. However, few studies have focused on the biochemical and molecular mechanisms underlying OMV-signaling during symbiosis onset and development. We show here that SypC, an OMV protein of the bioluminescent symbiont Vibrio fischeri, is taken up by cells of the squid host Euprymna scolopes where it assumes a new function, i.e., the facilitation of symbiont-induced light-organ morphogenesis. SypC is a Wza-like outer-membrane protein found in host-associated Vibrionaceae, and is essential for V. fischeri biofilm formation. Colonization or direct treatment with V. fischeri OMVs triggers host development, which is reduced or delayed if the host is instead exposed to a sypC mutant or its OMVs. RNA-seq analyses comparing light-organs colonized by the mutant versus its parent strain revealed differential expression of host genes involved in immune responses and tissue morphogenesis. Immunocytochemical imaging revealed that, within the light-organ crypts, SypC-bearing OMVs are taken up by the host’s macrophage-like cells, revealing the mechanism by which SypC travels throughout the tissue to trigger morphogenesis. Taken together, the data show that, in addition to its role in biofilm formation, SypC has a second function promoting colonization and the induction of symbiotic-tissue development. These findings provide a critical piece of a puzzle whereby a rich array of host and symbiont molecules work in concert to orchestrate normal symbiont colonization and host development within the first hours to days of symbiosis.
2026-02-25 | GSE307160 | GEO