Mastoiditis caused by novel sequence type of non toxigenic toxin gene-bearing (NTTB) Corynebacterium diphtheriae
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB90574 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Diphtheria toxoid vaccines are among the oldest and safest vaccines known. The basic principle of production is the inactivation of purified diphtheria toxin by formaldehyde cross-linking, which converts the potentially fatal toxin in a completely harmless protein aggregate, which is still immunogenic. Since in addition to diphtheria toxin also other proteins might be secreted by Corynebacterium diphtheriae, we assumed that diphtheria toxoid might not be the only component present in the vaccine. Therefore, we established a protocol to reverse formaldehyde cross-linking and carried out mass spectrometric analyses. Different secreted, membrane-associated and cytoplasmic proteins of C. diphtheriae were detected in several vaccine preparations from across the world. Western blot analyses indicated that these are immunogenic and may therefore support protection against C. diphtheriae. Furthermore, we could show that the vaccines also induce antibodies directed against diphtheria toxin secreted by Corynebacterium ulcerans, an emerging pathogen evoking diphtheria-like illness and skin infections.
2019-04-17 | PXD009289 | Pride
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:RNA degradation is a crucial process in bacterial cells for maintaining proper transcriptome homeostasis and coping with changing environments. A specialized ribonuclease known as RNase J (RnJ) participates in mRNA turnover in many Gram-positive bacteria; however, nothing is known about this process in Corynebacterium diphtheriae, nor is the identity of this RNase. We report here that C. diphtheriae DIP1463 encodes a predicted RnJ homolog, comprised of an N-terminal beta-lactamase domain, followed by beta-CASP and C-terminal domains. We show that a recombinant protein encompassing the beta-lactamase domain possessed 5’-exoribonuclease activity, which was abolished by alanine-substitution of conserved catalytic residues His186 and His188. Intriguingly, deletion of DIP1463/rnj in C. diphtheriae caused slow growth and augmented cell width. Comparative RNA-seq analysis revealed that RnJ controls a large regulon encoding many factors predicted to be involved in biosynthesis, regulation, transport, and iron acquisition. One up-regulated gene in ∆rnj mutant is ftsH, coding for the cell division protein FtsH, an inner membrane protease. Interestingly, overexpression of FtsH in the wild-type strain also caused cell-width augmentation. However, unlike the rnj mutant, which was attenuated in a Caenorhabditis elegans model of infection, the FtsH-overexpressing strain exhibited the same virulence phenotype as the wild-type strain. Remarkably, under iron-depleted conditions, production of the exotoxin diphtheria toxin was significantly reduced in the rnj mutant compared to the wild-type strain, likely due to dysregulated secretion of the toxin. Evidently, RNase J is a key ribonuclease that post-transcriptionally influences the expression of factors vital to C. diphtheriae physiology and virulence.
2021-02-08 | GSE165533 | GEO
Project description:Queensland C. diphtheriae toxin gene positive case
| PRJEB23872 | ENA
Project description:We assessed changes in gene expression in response to iron availability for the human pathogen Corynebacterium diphtheriae. Expression profiles of wild-type C. diphtheriae strain 1737 grown in semi-defined metal-poor media (mPGT) in iron-limiting (0.5 µM iron chloride supplementation) and iron-replete (10 µM supplementation) conditions were compared; the expression profiles of wild-type C. diphtheriae strain 1737 during growth in iron-replete conditions was also compared against an isogenic ΔdtxR mutant grown in iron-replete conditions. Three biological replicates were prepared by isolating total RNA from mid-logarithmic growth cultures and ten genes (dip0169, dip0415, dip1061, dip1062, dip2330, dip1486, dip0173, dip1252, dip1866, and dip0281) were quantified by real-time PCR to validate the array results. Corynebacterium diphtheriae is the causative agent of the severe respiratory disease, diphtheria. Diphtheria Toxin (DT), encoded by the tox gene, is the potent exotoxin secreted by C. diphtheriae responsible for much of the morbidity and mortality of diphtheria. Expression of the tox gene is regulated by the Diphtheria Toxin Repressor (DtxR) and iron. In addition to the regulation of toxin expression, DtxR functions as a global iron-dependent regulatory factor that mediates iron homeostasis in C. diphtheriae. While numerous genes regulated by DtxR and iron are known, a genome-wide study of both the iron and DtxR regulons is lacking in C. diphtheriae. Here, we report novel iron- and DtxR-regulated genes revealed by a comprehensive transcriptomic analysis. Not all identified genes appear to be repressed by iron and DtxR; some genes were found to be induced by iron in a DtxR-dependent manner, a mechanism of regulation not previously described in C. diphtheriae. Using a prediction algorithm (MEME) and electrophoretic mobility shift assays, we verified DtxR binding to sequences upstream of several newly identified genes. Furthermore, we characterized expression of ferritin (ftn) and catalase (cat), which are both induced by iron, but differentially affected by DtxR. We identified three DtxR binding sites in the ftn promoter, while analysis of the cat promoter establishes a role for DtxR in cat expression and suggests complex regulation by additional regulators. Collectively, these results expand our knowledge on the function of DtxR and the diverse roles of this regulatory protein in controlling gene expression.
2018-09-07 | GSE119621 | GEO
Project description:Fatal respiratory diphtheria caused by Beta-lactam-resistant toxigenic Corynebacterium diphtheriae
| PRJNA473263 | ENA
Project description:Corynebacterium diphtheriae and non-toxigenic C. ulcerans at a horse stable in Finland, 2021
| PRJEB61304 | ENA
Project description:Background: The human pathogen Corynebacterium diphtheriae is the causative agent of the disease diphtheria. In the 1990s a large diphtheria outbreak in Eastern Europe was caused by the strain C. diphtheriae NCTC 13129. Although the genome was sequenced several years ago, not much is known about the transcriptome. Our aim was to use RNA Sequencing to close this knowledge gap and gain insights into the transcriptional landscape of C. diphtheriae. Results: We applied two different RNA Sequencing techniques, one to retrieve 5' ends of primary transcripts and one to obtain full length transcripts, to gain insights into various features of the C. diphtheriae NCTC 13129 transcriptome. By examining the data we identified 1,657 transcription start sites (TSS) of which 1,229 were assigned to genes and 428 to putative novel transcripts. By using the TSS data SigA promotor regions and their motifs could be analyzed in detail, revealing a well conserved –10 but unconserved –35 motif, respectively. Furthermore with the TSS data in hand 5' UTR lengths were explored. The observed 5' UTRs range from leaderless, which make up 20 % of all genes, up to over 450 bp long leaders, which may harbor regulatory functions. The C. diphtheriae transcriptome consists of 470 operons which are further divided into 167 sub-operon structures. In addition we discovered that the deletion of the iron sensing transcription regulator DtxR, which also controls expression of diphtheria toxin (DT), has a strong influence on general gene expression. Nearly 15 % of the genome is differentially expressed, indicating that DtxR might have other functions next to regulation of iron metabolism and DT. Furthermore we shed light on the transcriptional landscape of the DT encoding gene tox and present evidence for an additional TSS and three tox antisense RNAs, which might reveal new ways of transcriptional regulation. Conclusions: This study presents extensive insights into the transcriptome of C. diphtheriae and provides a basis for future studies regarding transcriptional regulators, gene characterization and the tox gene in particular.
2018-01-12 | GSE98202 | GEO
Project description:Diphtheria is a severe upper respiratory disease that can cause fatal infections. It is known to produce diphtheria toxin and a range of other virulence factors, particularly when it encounters low levels of iron at sites of infection. Genomic sequencing of the NCTC13129 reference strain and its relatives responsible for the Eastern European outbreak in the 1990s revealed the presence of pathogenicity islands that contain a number of genes that encode for surface and secreted virulence factors, including pili, heme-acquisition machinery, and antimicrobial-resistance genes. Despite its clinical relevance and use as a model bacterium for research purposes, no proteomic study reported to date has rigorously defined the exoproteome and surfaceome in any tox-producing C. diphtheriae strain or defined how these proteomes change in response to iron limitation. Thus, defining the full complement of secreted (exoproteome) and surface (surfaceome) protein factors produced by C. diphtheriae that enables it to colonize its host promises to provide insight into how it both causes and prevents disease. To gain insight into how it colonizes its host we have identified iron-dependent changes in the exoproteome and surfaceome of C. diphtheriae strain 1737 using a combination of whole-cell fractionation, intact cell surface proteolysis, and quantitative proteomics. We first performed whole-cell fractionation and surface proteomics to quantitatively evaluate the exoproteome and surfaceome under low-iron growth conditions. For each protein we quantified its degree of secretion and surface-exposure by normalizing supernatant and surface digest abundances to fractions derived from the whole-cell lysate. Then, we performed differential abundance on secreted (supernatant) and surface (surface proteolysis) proteins under three different iron conditions that tested both the effect of iron concentration and iron source (e.g. free iron or heme from hemoglobin) on the exoproteome and surfaceome, respectively. All experiments were performed in biological triplicate, for a total of 33 LC-MS/MS runs.
2025-05-06 | PXD051674 | Pride
Project description:We assessed changes in gene expression in response to manganese availability for the human pathogen Corynebacterium diphtheriae. Total RNA was harvested from wild-type C. diphtheriae strain 1737 and an isogenic ΔmntR (dip0619) grown in semi-defined metal-limited media (mPGT) without or with 5 µM manganese chloride supplementation. Three biological replicates were prepared and five genes were assessed by real-time PCR to validate the array results: dip0124, dip0169, dip0615, dip1923, and dip2261. (Abstract) Corynebacterium diphtheriae is the causative agent of a severe respiratory disease in humans. The bacterial systems required for infection are poorly understood, but the acquisition of metals such as manganese (Mn) are likely critical for host colonization. MntR is a Mn-dependent transcriptional regulator in C. diphtheriae and was previously shown to repress the expression of the mntABCD genes, which encode an ABC metal transporter. However, other targets of Mn and MntR regulation in C. diphtheriae have not been identified. In this study, we use comparisons between the gene expression profiles of wild-type C. diphtheriae strain 1737 grown without or with Mn supplementation and comparisons of gene expression between wild-type and an mntR mutant to characterize the C. diphtheriae Mn and MntR regulon. MntR was observed to both repress and induce the expression of various target genes in a Mn-dependent manner. Genes induced by MntR include the Mn-superoxide dismutase, sodA, and the putative ABC transporter locus, iutABCD. DNA binding studies showed that MntR interacts at the promoter regions for several genes identified in the expression study, and a 17-bp consensus MntR DNA binding site was identified. We found that an mntR mutant displayed increased sensitivity to Mn and Cd that could be alleviated by the additional deletion of the mntA-D transport locus, providing evidence that the MntABCD transporter functions as a Mn uptake system in C. diphtheriae. The findings in this study further our understanding of metal uptake systems and global metal regulatory networks in this important human pathogen.
2021-05-06 | GSE173960 | GEO