Ontology highlight
ABSTRACT:
PROVIDER: PRJNA715821 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR14011062_1.fastq.gz | Fastqsanger.gz | |||
| SRR14011062_2.fastq.gz | Fastqsanger.gz | |||
| SRR14011063_1.fastq.gz | Fastqsanger.gz | |||
| SRR14011063_2.fastq.gz | Fastqsanger.gz | |||
| SRR14011064_1.fastq.gz | Fastqsanger.gz |
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Project description:Persistence of Listeria monocytogenes in retail deli environments is a serious food safety issue, potentially leading to cross-contamination of ready-to-eat foods such as deli meats, salads, and cheeses. We previously discovered strong evidence of L. monocytogenes persistence in delis across multiple states. We hypothesized that this was correlated with isolates’ innate characteristics, such as biofilm-forming capacity or gene differences.We further chose four isolates for RNA-sequencing analysis and compared their global biofilm transcriptome to their global planktonic transcriptome. Analysis of biofilm vs planktonic gene expression did not show the expected differences in gene expression patterns. Overall, L. monocytogenes persistence in the deli environment is likely a matter of poor sanitation and/or facility design, rather than isolates’ biofilm-forming capacity, sanitizer tolerance, or genomic content
2021-06-11 | GSE176617 | GEO
Project description:Listeria monocytogenes is a food-borne pathogen and the causative agent of listeriosis, an infection which typically arises through the consumption of contaminated foodstuffs. L. monocytogenes is a psychotrophic and facultatively anaerobic; properties which permit growth under refrigeration conditions and within modified atmosphere packaging. Through transcriptional changes L. monocytogenes is able to mount adaptive responses against stressors. Such responses typically cross protect against subsequent stresses.
2016-12-30 | GSE84879 | GEO
Project description:Listeria monocytogenes is a human, food-borne pathogen. Genomic comparisons between L. monocytogenes and Listeria innocua, a closely related non-pathogenic species, were pivotal in the identification of protein coding genes essential for virulence. However, no comprehensive comparison has focused on the non-coding genome. We used strand-specific cDNA sequencing to produce genome-wide transcription start site (TSS) maps for both organisms, and developed a publicly available integrative browser to visualize and analyze both transcriptomes in different growth conditions and genetic backgrounds. Our data revealed conservation across most transcripts, but significant divergence between the species in a subset of non-coding RNAs. In L. monocytogenes we identified 113 sRNAs and 70 asRNAs, significantly increasing the repertoire of non coding RNAs in this species. Remarkably, we identified a class of long antisense transcripts (lasRNAs) that overlap one gene while also serving as the 5M-bM-^@M-^Y UTR of the adjacent divergent gene. Experimental evidence suggests that lasRNAs transcription inhibits expression of one operon while activating the expression of another. Such lasRNA/operon structure, termed "excludon", might represent a novel form of regulation in bacteria. Construction of consensus TSS-maps in Listeria monocytogenes and Listeria innocua by applying 5'-end sequencing on samples in different conditions and genetic backgrounds.
2012-05-01 | E-GEOD-36060 | biostudies-arrayexpress
Project description:Listeria monocytogenes strains classify into at least three distinct phylogenetic lineages. Correlations exist between lineage classification and source of bacterial isolation, e.g., human clinical and food isolates usually classify into either lineage I or II, however, human clinical isolates are over-represented in lineage I while food isolates are over-represented in lineage II. σB, a transcriptional regulator previously demonstrated to contribute to environmental stress response and virulence in L. monocytogenes lineage II strains, was hypothesized to provide differential capabilities for L. monocytogenes survival in various niches (e.g., food vs. human clinical). To determine if σB contributions to stress response and virulence differ across diverse L. monocytogenes strains, ΔsigB mutations were created in strains from lineages I, II, IIIA, and IIIB. Paired parent and ΔsigB mutant strains were tested for acid and oxidative stress survival, Caco-2 cell invasion efficiency, and virulence using the guinea pig listeriosis infection model. Parent and ΔsigB mutant strain transcriptomes were compared using whole-genome expression microarrays. σB contributed to virulence in each strain. However, while σB contributed significantly to acid and oxidative stress survival and Caco-2 cell invasion in lineage I, II, and IIIB strains, σB contributions were not significant for these phenotypes in the lineage IIIA strain. A core set of 63 genes was positively regulated by σB in all four strains; different total numbers of genes were positively regulated by σB in each strain. Our results suggest that σB universally contributes to L. monocytogenes virulence, but specific σB-regulated stress response phenotypes vary among strains.
2010-06-01 | E-GEOD-21427 | biostudies-arrayexpress
Project description:In several gram-positive bacterial genera including Bacillus, Staphylococcus, and Listeria, sigma B (σB) has been identified as a stress-responsive alternative sigma factor responsible for initiating transcription of genes (the σB regulon) involved in response to stress-inducing environmental conditions. In L. monocytogenes, a foodborne pathogen of considerable threat to public health and the food industry, σB is involved in regulation of stress response and virulence gene expression. We have defined the σB regulon in L. monocytogenes during early stationary phase and under salt stress (0.3M NaCl) conditions using whole-genome microarrays, identifying 168 genes that generated ≥2.0-fold higher signals in the parental strain 10403S than in an isogenic sigB null mutant (ΔsigB), categorized into nine functional groups including stress-response genes (12), virulence genes (5), and genes related to transport (26) and metabolism (45). To gain a broader biological perspective of the σB stress response system, we applied these microarrays to Listeria innocua under the same environmental conditions. Our studies revealed 64 candidates in the L. innocua σB regulon with ≥2.0-fold higher signals in the parent than in a ΔsigB mutant; 49 of the 64 genes overlap with the L. monocytogenes σB regulon, indicating extensive overlap in σB-controlled genes between the two species. Further transcriptional analysis using TaqMan quantitative real time RT-PCR was performed for selected genes that displayed contrasting fold changes among the four microarray data sets (two stress conditions per species). We report novel members of the L. monocytogenes σB regulon, as well as the initial definition of the L. innocua σB regulon. Our comparative studies of the σB stress response systems in L. monocytogenes and L. innocua revealed features of the σB regulon that are conserved and unique to the two species. Keywords: Listeria monocytogenes, Listeria innocua, SigB regulon, salt stress, stationary phase
2007-11-29 | GSE7492 | GEO
Project description:Listeria monocytogenes strains classify into at least three distinct phylogenetic lineages. Correlations exist between lineage classification and source of bacterial isolation, e.g., human clinical and food isolates usually classify into either lineage I or II, however, human clinical isolates are over-represented in lineage I while food isolates are over-represented in lineage II. σB, a transcriptional regulator previously demonstrated to contribute to environmental stress response and virulence in L. monocytogenes lineage II strains, was hypothesized to provide differential capabilities for L. monocytogenes survival in various niches (e.g., food vs. human clinical). To determine if σB contributions to stress response and virulence differ across diverse L. monocytogenes strains, ΔsigB mutations were created in strains from lineages I, II, IIIA, and IIIB. Paired parent and ΔsigB mutant strains were tested for acid and oxidative stress survival, Caco-2 cell invasion efficiency, and virulence using the guinea pig listeriosis infection model. Parent and ΔsigB mutant strain transcriptomes were compared using whole-genome expression microarrays. σB contributed to virulence in each strain. However, while σB contributed significantly to acid and oxidative stress survival and Caco-2 cell invasion in lineage I, II, and IIIB strains, σB contributions were not significant for these phenotypes in the lineage IIIA strain. A core set of 63 genes was positively regulated by σB in all four strains; different total numbers of genes were positively regulated by σB in each strain. Our results suggest that σB universally contributes to L. monocytogenes virulence, but specific σB-regulated stress response phenotypes vary among strains.
2010-06-01 | GSE21427 | GEO
Project description:The SOS response is a conserved pathway that is activated under certain stress conditions and is regulated by the repressor LexA and the activator RecA. The food-borne pathogen Listeria monocytogenes contains RecA and LexA homologs, but their roles in Listeria have not been established. In this study, we identified the SOS regulon in L. monocytogenes by comparing the transcription profiles of the wild-type strain and the ΔrecA mutant strain after exposure to the DNA damaging agent mitomycinC (MMC). The SOS response is an inducible pathway involved in DNA repair, restart of stalled replication forks, and in induction of genetic variation in stressed and stationary phase cells. It is regulated by LexA and RecA. LexA is an autoregulatory repressor which binds to a consensus sequence in the promoter region of the SOS response genes, thereby repressing transcription. A consensus LexA binding motif for L. monocytogenes has not been identified thus far. Generally, the SOS response is induced under circumstances in which single stranded DNA accumulates in the cell. This results in activation of RecA, which in turn stimulates cleavage of LexA, and ultimately in the induction of the SOS response. Keywords: stress response, loop design, SOS response, mitomycin c, listeria monocytogenes, RecA, LexA
2009-11-25 | GSE12634 | GEO
Project description:Listeria monocytogenes is a food-borne pathogen which causes listeriosis. It is an intracellular parasite invading the epithelial cells where it escapes from the vacuole into the host cytoplasm to replicate, using actin-based motility to move within and between cells. The intracellular life cycle is well documented whereas the time spent in the lumen of the intestine is poorly understood. The aim of this study was to investigate the mechanism by which L. monocytogenes adapts to the environment of the small intestine prior to invasion. Specifically, to determine if the PrfA regulon, that encodes the virulence factors of L. monocytogenes, is switched on by signals within the intestinal lumen. L. monocytogenes were grown under aerobic or microaerobic conditions with glucose or glycerol as carbon source.
2023-11-24 | E-MTAB-12856 | biostudies-arrayexpress
Project description:Peracetic acid (PAA), a strong oxidizing agent, has been widely used as a disinfectant in food processing settings as it does not produce harmful chlorinated by-products. In the present study, the transcriptional response of Listeria monocytogenes to 2.5 ppm of PAA was assessed using RNA-sequencing (RNA-seq). Our analysis revealed 12 differentially expressed genes, of which 9 were up-regulated (ohrR, ohrA, rpsN, lmo0637, lmo1973, fur, lmo2492, zurM, and lmo1007), and 3 were down-regulated (argG, lmo0604, lmo2156) in PAA treated samples compared to the control samples. A non-coding small RNA (rli32) was also found to be down-regulated. In detail, the organic peroxide toxicity protection (OhrA-OhrR) system, the metal homeostasis genes fur and zurM, the SbrE-regulated lmo0636-lmo0637 operon and a carbohydrate phosphotransferase system (PTS) operon component were induced under exposure of L. monocytogenes to PAA. Hence, this study identified key elements involved in the primary response of L. monocytogenes to oxidative stress caused by PAA. The investigation of the molecular mechanism of PAA response in L. monocytogenes is of utmost importance for the food industry, as this response can be induced in food-processing environments, as a result of inadequate rinsing during the disinfection process, that lead to PAA residues at low concentrations.
2024-10-04 | GSE269393 | GEO