Project description:Pandemic and endemic strains of Vibrio cholerae arise from toxigenic conversion by the CTXφ bacteriophage, a process by which CTXφ infects non-toxigenic strains of V. cholerae. CTXφ encodes the cholera toxin, an enterotoxin responsible for the watery diarrhea associated with cholera infections. Despite the critical role of CTXφ during infections, signals that affect CTXφ-driven toxigenic conversion or expression of the CTXφ-encoded cholera toxin remain poorly characterized, particularly in the context of the gut mucosa. Here, we identify mucin polymers as potent regulators of CTXφ-driven pathogenicity in V. cholerae. Our results indicate that mucin-associated O-glycans block toxigenic conversion by CTXφ and suppress the expression of CTXφ-related virulence factors, including the toxin co-regulated pilus and cholera toxin, by interfering with the TcpP/ToxR/ToxT virulence pathway. By synthesizing individual mucin glycan structures de novo, we identify the Core 2 motif as the critical structure governing this virulence attenuation. Overall, our results highlight a novel mechanism by which mucins and their associated O-glycan structures affect CTXφ-mediated evolution and pathogenicity of V. cholerae, underscoring the potential regulatory power housed within mucus.
2022-12-01 | GSE213598 | GEO
Project description:Vibrio cholerae non-toxigenic strains from natural reservoirs
Project description:In presence of high concentrations of L-arabinose, Vibrio cholerae enters into a non-proliferative state. In V. cholerae, when L-arabinose in present into the media, it is incorporated and metabolized through the galactose pathway. In the present datasets we show that in presence of L-arabinose, transposon insertions in the galactose pathway confer a resistance to the detrimental effect of L-arabinose.
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 exposed wild-type Vibrio cholerae E7496, multiple Vibrio cholerae virulence factor deleted genes with intact hemolysin A gene [CVD109] and without hemolysin A gene [CVD110] in E7946, and E.coli OP50 to wild-type C.elegans N2 for 18 hours. We used microarrays to detail the global gene expression and identified distinct classes of up-regulated and down-regulated genes during this process. C. elegans were exposed to Vibrio cholerae and E.coli then hybridization on Affymetrix microarray chips.
Project description:We used RNA-seq to determine transcriptional profiles of whole guts or IPCs isolated from guts infected with wild type or type VI secretion system deficient Vibrio cholerae. We found significant differences between guts and progenitor cells infected wild type or type VI secretion system deficient Vibrio cholerae.
Project description:We exposed wild-type Vibrio cholerae E7496, multiple Vibrio cholerae virulence factor deleted genes with intact hemolysin A gene [CVD109] and without hemolysin A gene [CVD110] in E7946, and E.coli OP50 to wild-type C.elegans N2 for 18 hours. We used microarrays to detail the global gene expression and identified distinct classes of up-regulated and down-regulated genes during this process.
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.
