Probing the protein inventory of the human pathogen Clostridium difficile
ABSTRACT: The anaerobic and spore-forming bacterium Clostridium difficile has turned into an intensively studied species which can be attributed to increasing numbers of infections and rising costs for the health care system. This dataset represents a benchmark proteome of reference strain C. difficile 630erm and provides mass spectrometry based details on identified proteins which was generally missing from hitherto published datasets. An elaborate annotation and visualization of the 3764 open reading frames will serve as a valuable base for researchers trying to evaluate results of global expression studies. Furthermore, protein expression of late exponentially growing cells in the complex medium BHI and in C. difficile minimal medium was compared. Whereas abundance of proteins of DNA metabolism, protein synthesis and cell envelope showed no variation, enzymes for the biosynthesis of some vitamins and purine as well as proteins involved in butanoate fermentation differed significantly depending on the growth medium.
Project description:Analysis of Clostridium difficile (Cd) from the cecal contents of germ-free mice or Bacteroides thetaiotaomicron (Bt)-monocolonized mice on a standard, polysaccharide rich diet or polysaccharide deficient diet 5 days after infection. Results identify genes that are involved in the Cd response to diet, in vivo colonization and in interactions with Bt. In vitro transcriptional profiles of Clostridium difficile obtained from cecal contents of germ-free or Bt-monocolonized mice on a standard, polysaccharide rich or polysaccharide deficient diet. 4 samples/group. 2 control genomic DNA samples for Clostridium difficile and 2 reference genomic DNA samples for Bacteroides thetaiotaomicron Please note that 4 control samples (genomic DNA) were used to determine whether the genomic DNA correctly bound to the probes and thus, were not included in data processing (i.e no processed/normalized data).
Project description:Clostridium difficile infection (CDI) is typically associated with disturbed gut microbiota and changes related to decreased colonization resistance against C. difficile are well described. However, nothing is known about possible effects of C. difficile on gut microbiota restoration during or after CDI. In this study, we have mimicked such a situation by using C. difficile conditioned medium of six different C. difficile strains belonging to PCR ribotypes 027 and 014/020 for cultivation of fecal microbiota. A marked decrease of microbial diversity was observed in conditioned medium of both tested ribotypes. The majority of differences occurred within the phylum Firmicutes, with a general decrease of gut commensals with putative protective functions (i.e. Lactobacillus, Clostridium_XIVa) and an increase in opportunistic pathogens (i.e. Enterococcus). Bacterial populations in conditioned medium differed between the two C. difficile ribotypes, 027 and 014/020 and are likely associated with nutrient availability. Fecal microbiota cultivated in medium conditioned by E. coli, Salmonella Enteritidis or Staphylococcus epidermidis grouped together and was clearly different from microbiota cultivated in C. difficile conditioned medium suggesting that C. difficile effects are specific. Our results show that the changes observed in microbiota of CDI patients are partially directly influenced by C. difficile.
Project description:Protein expression is regulated by production and degradation of mRNAs and proteins, but their specific relationships remain unknown. We combine measurements of protein production and degradation and mRNA dynamics to build a quantitative genomic model of the differential regulation of gene expression in LPS stimulated mouse dendritic cells. Changes in mRNA abundance play a dominant role in determining most dynamic fold changes in protein levels. Conversely, the preexisting proteome of proteins performing basic cellular functions is remodeled primarily through changes in protein production or degradation, accounting for over half of the absolute change in protein molecules in the cell. Thus, the proteome is regulated by transcriptional induction of novel cellular functions and remodeling of preexisting functions through the protein life cycle. Mouse primary dendritic cells were treated with LPS or mock stimulus and profiled over a 12-hour time course. Cells were grown in M-labeled SILAC media, which was replaced with H-labeled SILAC media at time 0. Aliquots were taken at 0, 0.5, 1, 2, 3, 4, 5, 6, 9, and 12 hours post-stimulation and added to equal volumes of a master mix of unlabeled (L) cells for the purpose of normalization. RNA-Seq was performed at 0, 1, 2, 4, 6, 9, and 12 hours post-stimulation.
Project description:Clostridioides difficile (formerly Clostridium difficile) is a Gram-positive, spore-forming pathogen which cases drug-induced Clostridioides difficile-associated diseases in hospitals worldwide. A detailed analysis of the proteome may provide new targets for drug development or therapy strategies to combat this pathogen. So far, quantitative proteome analyses could only be carried out by label-free or chemical labeling methods. However, the application of metabolic labeling would allow for accurate quantification of significant differences, even in the case of very small changes. Additionally, it would be possible to perform bias free studies of the membrane or surface proteome which require elaborated preparations and are therefore prone to higher standard deviations during the quantification. Up to now, the implementation of metabolic labeling strategies of C. difficile was hampered by the very specific metabolic requirements of this anaerobic pathogen. To solve this problem, media were evaluated and the cultivation procedure with 15N labeled media for the C. difficile 630Δerm strain was optimized to gain a high incorporation rate. In the following proof-of-principle experiment, the cytosolic sub-proteomes of C. difficile cells of three different cultivation media and two growth phases were analyzed resulting in reproducible data which are shown in detail.
Project description:Recently, we engineered a tunable rhamnose promoter-based setup for the production of recombinant proteins in E. coli. This setup enabled us to show that being able to precisely set the production rate of a secretory recombinant protein is critical to enhance protein production yields in the periplasm. It is assumed that precisely setting the production rate of a secretory recombinant protein is required to harmonize its production rate with the protein translocation capacity of the cell. Here, using proteome analysis we show that enhancing periplasmic production of human Growth Hormone (hGH) using the tunable rhamnose promoter-based setup is accompanied by increased accumulation levels of at least three key players in protein translocation; the peripheral motor of the Sec-translocon SecA, leader peptidase (LepB) and the cytoplasmic membrane protein integrase/chaperone YidC. Thus, enhancing periplasmic hGH production leads to increased Sec-translocon capacity, increased capacity to cleave signal peptides from secretory proteins and an increased capacity of an alternative membrane protein biogenesis pathway, which frees up Sec-translocon capacity for protein secretion. When cells with enhanced periplasmic hGH production yields were harvested and subsequently cultured in the absence of inducer, SecA, LepB and YidC levels went down again. This indicates that when using the tunable rhamnose-promoter system to enhance the production of a protein in the periplasm, E. coli can adapt its protein translocation machinery for enhanced recombinant protein production in the periplasm.
Project description:In this study, we aimed at the characterization of C. difficile’s stress response to the main four human bile acids. Although, a phenotypically description of growth differences upon challenge with different bile acids has been described (Lewis 2016, Thanissery 2017), there is no information on the adaptation of gene expression available. We employed a comprehensive proteomics approach to record stress signatures of the unconjugated bile acids CA, CDCA, DCA and LCA during long-term-stress conditions and could depict a general stress response concerning all four bile acids, but also specific responses to only a single or a few of the different bile acids. Our results are a starting point for the understanding of how the individual bile acids cocktail of a patient can decide on the outcome of a C. difficile infection
Project description:In this study, we aimed at the characterization of C. difficile’s stress response to the main four human bile acids. Although, a phenotypically description of growth differences upon challenge with different bile acids has been described (Lewis 2016, Thanissery 2017), there is no information on the adaptation of gene expression available. We employed a comprehensive proteomics approach to record stress signatures of the unconjugated bile acids CA, CDCA, DCA and LCA in shock experiments as well as during long-term-stress conditions and could depict a general stress response concerning all four bile acids, but also specific responses to only a single or a few of the different bile acids. Our results are a starting point for the understanding of how the individual bile acids cocktail of a patient can decide on the outcome of a C. difficile infection.
Project description:In this study, we used gel-free nanoLC-MS/MS-based proteomics to compare the protein profile of B. pertussis wild type and an isogenic hfq defective mutant strain under control an iron limited conditions. We found that Hfq affects the abundance of 302 proteins, which represents 8% of the total B. pertussis coding sequence. The absence of Hfq induced changes in the abundance of proteins involved in metabolic pathways, stress response and virulence. Hfq was also found involved in B. pertussis adaptation to iron starvation, one of the main stresses this pathogen faces inside the host. Altogether, these results indicate that B. pertussis Hfq is involved in bacterial physiological processes as well as bacterial pathogenesis.
Project description:In Escherichia coli, the Twin-arginine (Tat) secretion system is one of the main routes of the protein export to the periplasm. The Tat pathway secretes a set of proteins with important physiological functions. In our study, we investigated the influence of the deactivation of the Tat pathway on the E. coli cells. We applied a comprehensive and comparative proteomic analysis of the E. coli wild type and tat mutant. This dataset provides mass spectrometry based details on the abundances of proteins in cytoplasmic, periplasmic and membrane fractions. We observed that a tat deletion increases abundances of proteins involved in protein folding, degradation, responses to heat, oxidation, osmolarity, and cold. Moreover, the impairment of E. coli outer membrane resulted in the activation of proteins responsible for cell wall biogenesis. The tat deletion negatively affects the synthesis of iron transporters and imbalances its homeostasis in the cell.
Project description:C. difficile infection (CDI) is a common debilitating nosocomial infection associated with high mortality. Several CDI outbreaks have been attributed to ribotypes 027, 017, and 078. Clinical and experimental evidence indicates that the nonpathogenic yeast Saccharomyces boulardii CNCM I-745 (S.b) is effective for the prevention of CDI. However, there is no current evidence suggesting this probiotic can protect from CDI caused by outbreak-associated strains. We used established hamster models infected with outbreak-associated C. difficile strains to determine whether oral administration of live or heat-inactivated S.b can prevent cecal tissue damage and inflammation. Hamsters infected with C. difficile strain VPI10463 (ribotype 087) and outbreak-associated strains ribotype 017, 027, and 078 developed severe cecal inflammation with mucosal damage, neutrophil infiltration, edema, increased NF-?B phosphorylation, and increased proinflammatory cytokine TNF? protein expression. Oral gavage of live, but not heated, S.b starting 5 days before C. difficile infection significantly reduced cecal tissue damage, NF-?B phosphorylation, and TNF? protein expression caused by infection with all strains. Moreover, S.b-conditioned medium reduced cell rounding caused by filtered supernatants from all C. difficile strains. S.b-conditioned medium also inhibited toxin A- and B-mediated actin cytoskeleton disruption. S.b is effective in preventing C. difficile infection by outbreak-associated via inhibition of the cytotoxic effects of C. difficile toxins.