Expression profile of a parent and M-bM-^HM-^FlstC strain in regular and high salt conditions
Ontology highlight
ABSTRACT:
ORGANISM(S): Listeria monocytogenes
SUBMITTER: Atin Datta
PROVIDER: E-GEOD-56828 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Microarray analysis of the expression profiles of a parent and its derived ∆lstC mutant in normal and high salt conditions. The analysis was performed to determine which genes were altered in the mutant when grown in high salt conditions relative to the parent strain.
2014-04-16 | GSE56828 | GEO
Project description:A previously described low-fitness, high stress-resistant, variant of Listeria monocytogenes LO28 WT was subjected to an experimental evolution regime, selecting (in two parallel lines) for increased fitness in unstressed conditions. Evolved variants with increased fitness reverted to WT-like stress resistance. Whole genome sequencing and proteomics were used to identify differences between the ancestral and evolved strains.
2023-10-03 | PXD022732 | Pride
Project description:Bacteroidaceae are common gut microbiota members in all warm-blooded animals. However, if Bacteroidaceae are to be used as probiotics, the species selected for different hosts should reflect the natural distribution. In this study, we therefore evaluated host adaptation of bacterial species belonging to the family Bacteroidaceae. B. dorei, B. uniformis, B. xylanisolvens, B. ovatus, B. clarus, B. thetaiotaomicron and B. vulgatus represented human-adapted species while B. gallinaceum, B. caecigallinarum, B. mediterraneensis, B. caecicola, M. massiliensis, B. plebeius and B. coprocola were commonly detected in chicken but not human gut microbiota. There were 29 genes which were present in all human-adapted Bacteroides but absent from the genomes of all chicken isolates and these included genes required for the pentose cycle, and glutamate or histidine metabolism. These genes were expressed during an in vitro competitive assay, in which human-adapted Bacteroides species overgrew the chicken adapted isolates. Not a single gene specific for the chicken-adapted species was found. Instead, chicken adapted species exhibited signs of frequent horizontal gene transfer, of KUP, linA and sugE genes in particular. The differences in host adaptation should be considered when the new generation of probiotics for humans or chickens is designed.
2020-09-28 | PXD020954 | Pride
Project description:Comparison of Listeria monocytogenes transcripts in different growth conditions (exponential phase 37 degrees C, stationary phase 37 degrees C, exponential phase 30 degrees C, hypoxia, human blood, murine intestinal lumen) and different mutant strains (wild-type versus prfA, sigB and hfq deletion mutants).
2009-04-24 | E-MEXP-2142 | biostudies-arrayexpress
Project description:Comparison of Listeria monocyotgenes gene expression in different growth conditions (exponential phase 37 degrees C, stationary phase 37 degrees C, exponential phase 30 degrees C, hypoxia, human blood, murine intestinal lumen) and different mutant strains (wild-type versus prfA, sigB and hfq deletion mutants).
2010-04-16 | E-MEXP-2138 | biostudies-arrayexpress
Project description:The foodborne pathogen Listeria monocytogenes experiences osmotic stress in many habitats, including foods and the gastrointestinal tract of the host. While osmotic stress induced changes in expression have been investigated for specific genes, identifying and understanding genome-wide temporal changes in the transcriptome due to salt stress will provide insights into how this pathogen adapts to and survives this stress, leading to development of new intervention strategies. To determine the short-term and long-term responses to salt stress, we exposed exponential phase cells of L. monocytogenes H7858 to 6% NaCl in Brain Heart Infusion (BHI) broth at 7°C and 37°C and extracted RNA after 2.5%, 5%, 10%, and 20% of lag phase and during exponential growth in BHI + 6% NaCl, and evaluated temporal changes in transcript levels with microarrays. The temperature dependent short-term response to salt stress included a significant increase in transcript levels of the alternative sigma factor σB, with maximum expression at 2.5-5% of lag phase at 37°C, and at 20% of lag phase at 7°C. Transcript levels of genes known to be regulated by σB, including inlAB, opuCA, glpFK, and gadBC, were significantly upregulated at the same relative time points as σB As indicated by significantly elevated transcript levels during exponential growth in BHI + 6% NaCl, genes encoding proteins involved in purine and pyrimidine synthesis and amino acid biosynthesis are part of the long-term response to salt stress at 37°C. Transcript levels of virulence genes plcA, mpl, actA, and plcB were also significantly upregulated during exponential growth under salt stress at 37°C. Genes encoding proteins involved in protein degradation and stability and cell membrane modifications are part of the long-term response to salt stress at 7°C. Overall, an initial alteration in the transcriptome occurs, decreasing transcript levels of genes encoding proteins involved in energy conversion and metabolism, while increasing transcript levels of those involved in the stress response controlled by σB, followed by a long-term response, including increased expression of genes encoding compatible solute transporters and general stress proteins, facilitating growth under salt stress. A reference design was used to analyze gene expression differences. Exponential phase cultures at 37C and at 7C were used as a reference for salt stressed samples at each temperature. Salt stressed samples from the same relative time point were compared across temperatures. 4 biological replicates were tested for each comparison.
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Project description:Helicobacter pylori, a pathogenic member of phylum Campylobacterota (formerly Epsilonproteobacteria), is recognized as the leading cause of several human gastric pathologies, including acute and chronic gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In the last two decades, the alarming increase of the antibiotic resistance levels to first-line and even “rescue” antibiotics, especially clarithromycin, metronidazole and levofloxacin, has led to a marked decrease of the eradication rates of traditional therapies. In previous works, we have validated the essential protein HsrA as an effective therapeutic target for H. pylori infection. HsrA is an OmpR/PhoB-type orphan response regulator, unique and highly conserved in members of phylum Campylobacterota, which appears involved in a variety of crucial physiological processes. In the present work, we carried out a transcriptomic analysis in order to discern the global effects of lethal concentrations of a bactericidal HsrA inhibitor on the H. pylori physiology. Treatment with the bactericidal HsrA inhibitor significantly changed the transcript levels of 367 open reading frames (ORF), of which 212 genes appeared upregulated and 155 genes resulted in downregulation, as compared with control samples. Thus, in vivo HsrA inhibition influenced, directly or indirectly, the expression of 23% of ORFs encoded by the H. pylori 26696 genome. Among the 268 differentially expressed genes (DEGs) with defined functions, two functional categories were highly enriched with downregulated genes involved in essential physiological processes: (1) ribosome biogenesis, and (2) electron transfer and oxidative phosphorylation.
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Project description:The extensively studied intracellular pathogen, L. monocytogenes, is an ideal model for identifying small-molecule agents for treating bacterial infections. By selecting specific biological targets in L. monocytogenes, which are common to Gram-positive pathogens, we could extrapolate drug discovery information derived from this well-studied bacterium. Attenuating the pathogenM-bM-^@M-^Ys virulence and stress response attributes without killing it, eliminates selective pressure caused by disruption of essential gene functions (as done by current antibiotics) and reduces the likelihood of developing microbes that are impervious to the effects of antibiotics. To this end, we have assessed multiple libraries of small organic compounds to identify inhibitors of L. monocytogenes M-OM-^CB, the alternative sigma factor common to several clinically relevant Gram-positive pathogens, such as Staphylococcus aureus, Bacillus cereus, and Bacillus anthracis. The role of M-OM-^CB as a transcriptional regulator of stress response and virulence makes it an ideal, well conserved target for chemotherapeutic development. Independent RNA isolations were performed for each growth experiment (log phase cells exposed to BHI+0.3M NaCl and BHI+0.3M NaCl + CMPD). Four biological replicates were used in competitive whole-genome microarray experiments. For the hybridizations, RNA from the wildtype parent strain L. monocytogenes 10403S were hybridized to RNA from the wildtype parent strain 10403S treated with CMPD.
2011-12-06 | E-GEOD-16887 | biostudies-arrayexpress
Project description:Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative bacterial pathogen associated with severe periodontitis and non-oral diseases. Clinical isolates of Aa display a rough (R) colony phenotype with strong adherent properties. Upon prolonged culturing, non-adherent strains with a smooth (S) colony phenotype emerge. To date, most virulence studies on Aa have been performed with S strains of Aa, whereas the virulence of clinical R isolates received relatively little attention. Since the extracellular proteome is the main bacterial reservoir of virulence factors, the present study was aimed at a comparative analysis of this sub-proteome fraction for a collection of R isolates and derivative S strains, in order to link particular proteins to the virulence of Aa with serotype b. To assess the bacterial virulence, we applied different infection models based on larvae of the greater wax moth Galleria mellonella, a human salivary gland-derived epithelial cell line, and freshly isolated neutrophils from healthy human volunteers. A total number of 351 extracellular Aa proteins was identified by mass spectrometry, with the S strains consistently showing more extracellular proteins than their parental R isolates. A total of 50 known extracellular virulence factors was identified, of which 15 were expressed by all investigated bacteria. Importantly, the comparison of differences in exoproteome composition and virulence highlights critical roles of 10 extracellular proteins in the different infection models. Altogether, our present study provides novel cues for understanding the virulence of Aa, and for development of potential preventive or therapeutic avenues to neutralize this important oral pathogen.
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