Project description:The PTS system is a central regulatory cascade in bacteria. Here, Vibrio cholerae PTS role was investagated during biofilm formation
Project description:To investigate the effect of conditions of culture on gene expression in Vibrio cholerae N16961 We then performed gene expression profiling analysis using data obtained from RNA-seq of 4 conditions of culture in biological duplicate
Project description:Type VI secretion systems (T6SS) are widely distributed among Vibrio species, yet their roles in the coexistence of toxigenic and non- toxigenic strains remain unclear. Here, we report a novel orphan T6SS effector-immunity module, TseVs-TsiVs, primarily harbored by non- toxigenic Vibrio cholerae. TseVs exhibits robust vibriocidal activity, specifically targeting susceptible Vibrios (lacking TsiVs). TseVs forms dual-membrane, ion-selective pores that collapse Na⁺/K⁺ homeostasis, resulting in membrane depolarization and ATP depletion. Remarkably, non-Vibrio bacteria evade TseVs through proton motive force (PMF)-dependent resilience, uncovering a previously unrecognized immunity-independent defense strategy. Furthermore, tseVs+ non- toxigenic V. cholerae strains are globally distributed and have dominated in recent decades, highlighting TseVs’s ecological significance in Vibrio population dynamics. By linking TseVs’s bioenergetic assassination to Vibrio population shifts, we demonstrate how T6SS effectors shape microbial genetic diversity. Our findings suggest that TseVs represents a promising model for precision antimicrobial strategies, minimizing collateral damage to commensal microbiota.
Project description:Identification of post translational modifications on Vibrio cholerae protein VesB (from purified VesB and culture supernatant) using in-gel digestion with trypsin, LC-MS/MS, database searching.
Project description:In marine Vibrio species, chitin-induced natural transformation enables bacteria to take up DNA from the external environment and integrate it into their genome via homologous recombination. Expression of the master competence regulator TfoX bypasses the need for chitin induction and drives expression of the genes required for competence in several Vibrio species. Here, we show that TfoX expression in two Vibrio campbellii strains, DS40M4 and NBRC 15631, enables high frequencies of natural transformation. Conversely, transformation was not achieved in the model quorum-sensing strain V. campbellii BB120 (previously classified as Vibrio harveyi). Surprisingly, we find that quorum sensing is not required for transformation in V. campbellii DS40M4. This result is in contrast to Vibrio cholerae that requires the quorum-sensing regulator HapR to activate the competence regulator QstR. However, similar to V. cholerae, QstR is necessary for transformation in DS40M4. To investigate the difference in transformation frequencies between BB120 and DS40M4, we used previously studied V. cholerae competence genes to inform a comparative genomics analysis coupled with transcriptomics. BB120 encodes homologs of all known competence genes, but most of these genes were not induced by ectopic expression of TfoX, which likely accounts for the non-functional natural transformation in this strain. Comparison of transformation frequencies among Vibrio species indicates a wide disparity among even closely related strains, with Vibrio vulnificus having the lowest functional transformation frequency. We show that ectopic expression of both TfoX and QstR is sufficient to produce a significant increase in transformation frequency in Vibrio vulnificus.
Project description:Investigation of whole genome gene expression level changes in a Vibrio cholerae O395N1 delta-nqrA-F mutant, compared to the wild-type strain. Total RNA recovered from wild-type cultures of VIbrio cholerae O395N1 and its nqrA-F mutant strain. Each chip measures the expression level of 3,835 genes from Vibrio cholerae O1 biovar eltor str. N16961 with twenty average probes/gene, with five-fold technical redundancy.
Project description:We have investigated the genomic and epigenetic consequences of co-culturing colorectal carcinoma cells with membrane vesicles from pathogenic bacteria Vibrio cholerae and non-pathogenic commensal bacteria Escherichia coli. Our study has revealed that membrane vesicles from pathogenic and commensal bacteria have a global impact on the gene expression of coloncarcinoma cells. The changes in gene expression correlated positively with both epigenetic changes and chromatin accessibility of promoters at transcription start sites of genes induced by both types of membrane vesicles. Moreover, we have demonstrated that membrane vesicles obtained only from V. cholerae induced the expression of genes associated with tumour differentiation. Altogether, our study suggests that the observed genomic changes in host cells might be due to specific components of membrane vesicles and does not require communication by direct contact with the bacteria.
Project description:The culture supernatant of wild-type (WT) Vibrio cholerae N16961 and mutant epsC∆PDZ strains were compared to determine which, if any, type II secretion system substrates were affected by the deletion of the PDZ domain of EpsC
