Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Characterization of a key region involved in the NO stress response of Bacillus cereus

ABSTRACT: Bacterial response to nitric oxide (NO) is of major importance for bacterial survival, as NO stress is a main actor of the eukaryote immune response. Several pathogenic bacteria have developed gene regulation systems involved in detoxification and in repairing the damages caused by NO. However, bacterial mechanisms of NO resistance are poorly described for Gram positive bacteria and especially Bacillus cereus. This food born and opportunistic pathogen does not have the common weapon against NO described in other pathogenic or non-pathogenic bacteria, such as the transcriptional regulators norR and nsrR, nor NO reductases. Using a transcriptomic approach, we investigated the mechanisms used by B. cereus to fight against NO stress. A cluster of 6 genes was identified to be particularly overexpressed in the early response to NO stress. This cluster contains an iron-sulphur cluster repair enzyme, a nitrite reductase and three enzymes involved in siroheme biosynthesis. We show a co-expression and a close genetic localization implying a functional link between those genes. This cluster may play a pivotal role in the defence mechanisms used by B. cereus to fight against NO stress during infection.

ORGANISM(S): Bacillus cereus

PROVIDER: GSE168681 | GEO | 2021/06/02

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

A novel hybrid kinase is essential for regulating the ÏB-mediated stress response of Bacillus cereus.

Project description:A common bacterial strategy for monitoring environmental challenges is to use two-component systems, which consist of a sensor histidine kinase (HK) and a response regulator (RR). In the food-borne pathogen Bacillus cereus, the alternative sigma factor ÏB is activated by the RR RsbY. Here we present strong indications that the PP2C-type phosphatase RsbY receives its input from the multi-sensor hybrid kinase BC1008 (renamed RsbK). Genome analyses revealed that, across bacilli, rsbY and rsbK are located in a conserved gene cluster. A B. cereus rsbK deletion strain was shown to be incapable of inducing ÏB upon stress conditions and was impaired in its heat adaptive response. Comparison of the wild-type and rsbK mutant transcriptomes upon heat shock revealed that RsbK was primarily involved in the activation of the ÏB-mediated stress response. Truncation of the RsbK RR receiver domain demonstrated the importance of this domain for ÏB induction upon stress. The domain architecture of RsbK suggests that in the B. cereus group and in other bacilli, environmental and intracellular stress signalling routes are combined into one single protein. This strategy is markedly different from the ÏB activation pathway in other low-GC Grampositives. Two different comparisons were performed (both in duplo and Cy5-Cy3 dye-swapped): (1) B. cereus WT 30Â°C versus B. cereus WT 42Â°C (10 min heat shock) (2) B. cereus WT 42Â°C versus B. cereus FM1404 42Â°C Data from comparisons (2) were subsequently compared with transcriptome data obtained previously by Van Schaik et al., 2007

2010-06-24 | E-GEOD-14589 | biostudies-arrayexpress

The sigmaB regulon of B. cereus ATCC14579

Project description:The alternative sigma factor sigmaB has an important role in the acquisition of stress-resistance in many gram-positive bacteria. In the foodborne pathogen Bacillus cereus sigmaB is activated strongly upon a heat shock and other stress conditions. Here we describe the identification of the set of sigmaB-regulated genes in B. cereus by DNA microarray analysis of the transcriptome upon a mild heat shock. A total of 24 genes could be identified as being sigmaB-dependent as witnessed by (i) significantly lower expression-levels of these genes in mutants deleted for sigB and rsbY (encoding the alternative sigma factor sigmaB and a PP2C phosphatase that acts as a crucial positive regulator of sigmaB-activity, respectively) than in the parental strain B. cereus ATCC 14579, and (ii) increased expression of these genes upon a heat shock. Newly identified members of the sigmaB-regulon of B. cereus include an ECF-sigma factor (sigmaZ), a histidine kinase and two genes that have predicted functions in spore germination. Our data indicate that the sigmaB-regulon of B. cereus is considerably smaller than that of other gram-positive bacteria. This appears to be in line with phylogenetic analyses of sigmaB in which sigmaB in the B. cereus group was suggested to be close to the ancestral form of sigmaB in gram-positive bacteria. Keywords: stress response, comparative genomics

2007-04-10 | GSE6005 | GEO

A novel hybrid kinase is essential for regulating the σB-mediated stress response of Bacillus cereus.

Project description:A common bacterial strategy for monitoring environmental challenges is to use two-component systems, which consist of a sensor histidine kinase (HK) and a response regulator (RR). In the food-borne pathogen Bacillus cereus, the alternative sigma factor σB is activated by the RR RsbY. Here we present strong indications that the PP2C-type phosphatase RsbY receives its input from the multi-sensor hybrid kinase BC1008 (renamed RsbK). Genome analyses revealed that, across bacilli, rsbY and rsbK are located in a conserved gene cluster. A B. cereus rsbK deletion strain was shown to be incapable of inducing σB upon stress conditions and was impaired in its heat adaptive response. Comparison of the wild-type and rsbK mutant transcriptomes upon heat shock revealed that RsbK was primarily involved in the activation of the σB-mediated stress response. Truncation of the RsbK RR receiver domain demonstrated the importance of this domain for σB induction upon stress. The domain architecture of RsbK suggests that in the B. cereus group and in other bacilli, environmental and intracellular stress signalling routes are combined into one single protein. This strategy is markedly different from the σB activation pathway in other low-GC Grampositives.

2009-12-17 | GSE14589 | GEO

The NsrR regulon of Escherichia coli K-12

Project description:Successful pathogens must be able to protect themselves against reactive nitrogen species generated either as part of host defence mechanisms, or as products of their own metabolism. The regulatory protein, NsrR (a member of the Rrf2 family of transcription factors), plays key roles in this stress response. Microarray analysis was carried out to reveal the regulon of NsrR. Keywords: Response to repressor titration and different growth conditions

2007-05-18 | GSE6781 | GEO

The sigmaB regulon of B. cereus ATCC14579

2010-07-01 | E-GEOD-6005 | biostudies-arrayexpress

RNA Atlas of Bacterial Human Pathogens Uncovers Stress Dynamics Linked to Bacterial Infections

Project description:Pathogenic bacteria encounter a variety of stressful host environments during infection. Their responses to meet these challenges protect them from deadly damages and aid in adaption to harmful environments. Bacterial products critical for this protection are therefore interesting as suitable targets for new antimicrobials. To shed light on the complex array of molecular pathways involved in bacterial stress responses we challenged 32 diverse human pathogenic bacteria to 11 infection related stress conditions and catalogued their transcriptomes. Initial analyses of the comprehensive data set showed that beside coding RNAs, known and yet unknown putative novel ncRNAs comprise a significant part of the responses. We also computed a scores for all genes to be used for predictions for their probability to be regulated at certain stresses. The core scores enabled identification of universal stress responders representing conserved gene products involved in basic mechanisms important for responses to multiple stresses. Further, the environmental specific core scores made it possible to predict functions of yet non-characterized and also hypothetical gene products. All data are collected in the PATHOGENEX interactive RNA atlas, which is made available to the research community providing ample opportunities for discovering new aspects of regulatory networks in pathogenic bacteria as well as identification of novel players critical for bacterial infectivity and maintenance of infections.

2021-04-23 | GSE152295 | GEO

Response of Bacillus cereus ATCC 14579 to challenges with sublethal concentrations of enterocin AS-48

Project description:Enterocin AS-48 is produced by Enterococcus faecalis S48 to compete with other bacteria in their environment. Due to its activity against various Gram positive and some Gram negative bacteria it has clear potential for use as a food preservative. Here, we studied the effect of enterocin AS-48 challenges on vegetative cells of Bacillus cereus ATCC 14579 by use of transcriptome analysis.

2010-04-08 | GSE15600 | GEO

New genetic biomarkers to differentiate pathogenic and clinically relevant Bacillus cereus strains

Project description:Bacillus cereus is the second leading cause of collective food poisoning in France. B. cereus is also associated with severe clinical infections leading to patient death in 10% of the cases. The emergence of B. cereus as a foodborne and opportunistic pathogen has intensified the need to distinguish strains of public health concern. In this work, by performing a screen on a large collection of B. cereus strains of varying pathogenic potential, we identified genetic determinants capable of discriminating B. cereus strains inducing negative clinical outcomes. The combination of 4 biomarkers is sufficient to accurately discern clinical strains from harmless strains. Three of the biomarkers are located on the chromosome, with a fourth one identifying a plasmid carried by most pathogenic strains. A 50 kbp region of this plasmid promotes the virulence potential of these strains and could thus be defined as a new pathogenicity island of B. cereus. These new findings help in the understanding of B. cereus pathogenic potential and complexity and may provide tools for a better assessment of the risks associated with B. cereus contamination to improve patient health and food safety.

2022-01-12 | GSE171128 | GEO

Transcripts regulated by elevated DKF-2 (WT background)

Project description:Transcriptional profiling was used to determine why DKF-2 (protein kinase D) deficiency and surfeit caused hypersensitivity and resistance, respectively, to a bacterial pathogen (P. aeruginosa 14). The studies show that DKF-2 contributes to C. elegans innate immunity by inducing expression of >75 genes that protect against pathogenic bacteria. Keywords: Induced imune response

2009-01-12 | GSE12456 | GEO

Novel inducible filamentous sliding motility identified in pathogenic Bacillus cereus group species

Project description:We isolated an atmospheric contaminant, subsequently identified as a new strain of Bacillus mobilis, which showed a novel, robust, inducible filamentous sliding motility and completely colonized a bacterial culture plate in less than 48 h under some conditions. This flagella-independent sliding motility was characterized by long filamentous cells at the expanding edge, and was induced when cells were inoculated onto lawns of metabolically inactive Campylobacter jejuni cells, heat killed bacterial biomass, and milk or blood dried onto agar plates. Phosphatidylcholine (PC), bacterial membrane components, and sterile human fecal extracts were sufficient to induce filamentous expansion. Screening of eight other Bacillus spp. (five from the B. cereus group and three other Bacillus spp.) showed that filamentous motility was conserved amongst B. cereus group species to varying degrees. RNAseq of filamentously expanding cells collected from PC and milk lawn plates in comparison to rod-shaped cells from control plates revealed that genes related to metabolism, ion and amino acid transport were differently regulated, genes controlling sporulation were reduced, and some virulence genes (e.g., hblA/B/C/D and plcR) were increased. We hypothesize that the robust and conserved nature of filamentous motility in pathogenic B. cereus group species can enhance bacterial colonization during host colonization.

2020-01-01 | GSE136873 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data