The quorum-sensing agr system protects Staphylococcus aureus from oxidative stress (overnight growth)
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ABSTRACT:
PROVIDER: PRJNA852598 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR19847304_1.fastq.gz | Fastqsanger.gz | |||
| SRR19847304_2.fastq.gz | Fastqsanger.gz | |||
| SRR19847305_1.fastq.gz | Fastqsanger.gz | |||
| SRR19847305_2.fastq.gz | Fastqsanger.gz | |||
| SRR19847306_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:The agr quorum-sensing system clearly links Staphylococcus aureus metabolism to virulence, but little is known about how agr alters metabolism to affect cell survival during severe stress. Recently, we reported that agr activity increases survival of bacteria during treatment with lethal concentrations of H2O2, a crucial host defense against S. aureus. Here we report that protection by agr extends to growth resumption during the exit from stationary phase. The data indicate that the agr functionality of a cell’s ancestor affects stress-resiliency after resuming growth. Protection against killing by H2O2 depended on the agr effector molecule RNAIII and Rot, a transcription factor targeted by RNAIII. Expression data revealed that Δagr strains shift to fermentation, suggesting that agr promotes aerobic respiration. Epistasis between mutation of agr and sortase, which anchors surface proteins to the cell wall, suggested that reduced killing by H2O2 of wild-type agr strains acts through down-regulation of surface proteins that perturb respiration. Respiration generates reactive oxygen species (ROS), moderate amounts of which can protect from subsequent challenge by lethal concentrations, explaining agr-mediated protection against subsequent lethal H2O2 doses. Increased survival of wild-type agr cells in response to H2O2 required sodA, which dismutates O2- to H2O2, suggesting that sodA helps induce the low, protective levels of ROS triggered by agr. Additionally, detrimental effects of the Δagr mutation require ahpC, which functions to decrease the intracellular level of H2O2. Deletion of ahpC or sortase attenuated neutrophil-mediated killing of Δagr strains, demonstrating the importance of priming in anticipation of impending immune attack.
2023-06-20 | GSE206916 | GEO
Project description:The agr quorum-sensing system clearly links Staphylococcus aureus metabolism to virulence, but little is known about how agr alters metabolism to affect cell survival during severe stress. Recently, we reported that agr activity increases survival of bacteria during treatment with lethal concentrations of H2O2, a crucial host defense against S. aureus. Here we report that protection by agr extends to growth resumption during the exit from stationary phase. The data indicate that the agr functionality of a cell’s ancestor affects stress-resiliency after resuming growth. Protection against killing by H2O2 depended on the agr effector molecule RNAIII and Rot, a transcription factor targeted by RNAIII. Expression data revealed that Δagr strains shift to fermentation, suggesting that agr promotes aerobic respiration. Epistasis between mutation of agr and sortase, which anchors surface proteins to the cell wall, suggested that reduced killing by H2O2 of wild-type agr strains acts through down-regulation of surface proteins that perturb respiration. Respiration generates reactive oxygen species (ROS), moderate amounts of which can protect from subsequent challenge by lethal concentrations, explaining agr-mediated protection against subsequent lethal H2O2 doses. Increased survival of wild-type agr cells in response to H2O2 required sodA, which dismutates O2- to H2O2, suggesting that sodA helps induce the low, protective levels of ROS triggered by agr. Additionally, detrimental effects of the Δagr mutation require ahpC, which functions to decrease the intracellular level of H2O2. Deletion of ahpC or sortase attenuated neutrophil-mediated killing of Δagr strains, demonstrating the importance of priming in anticipation of impending immune attack.
2023-06-20 | GSE206889 | GEO
Project description:The quorum-sensing agr system protects Staphylococcus aureus from oxidative stress
| PRJNA853358 | ENA
Project description:RNAseq of exponentially growing cultures of the four agr prototype strains used in the study to investigate if differential expression of regulators interacting with the agr system could explain the differences in AIP sensitivity. Abstract Staphylococcus aureus both colonizes humans and causes severe virulent infections. Virulence is regulated by the agr quorum sensing system and its autoinducing peptide (AIP), with dynamics at the single-cell level across four agr-types – each defined by distinct AIP sequences and capable of cross-inhibition – remaining elusive. Employing microfluidics, time-lapse microscopy, and deep-learning image analysis, we uncovered significant differences in AIP sensitivity among agr-types. We observed bimodal agr activation, attributed to intergenerational phenotypic stability and influenced by AIP concentration. Upon AIP stimulation, agr III showed AIP insensitivity, while agr II exhibited increased sensitivity and prolonged generation time. Beyond expected cross-inhibition of agr I by heterologous AIP II and III, the presumably cross-activating AIP IV also inhibited agr I. Community interactions across different agr-type pairings revealed four main patterns: stable or switched dominance, and delayed or stable dual activation, influenced by community characteristics. These insights underscore the potential of personalized treatment strategies considering virulence and genetic diversity.
2024-03-05 | E-MTAB-13859 | biostudies-arrayexpress
Project description:The Staphylococcus aureus accessory gene regulator (agr) is a prototype quorum-sensing system in Gram-positive bacteria and a paradigmatic example of gene regulation by a small regulatory RNA, RNAIII. Using genome-wide transcriptional profiling in the community-associated methicillin-resistant (CA-MRSA) strain MW2, we demonstrate here that in contrast to the current model of target gene regulation by agr, a large subset of agr-regulated genes is controlled independently of RNAIII. This group comprised predominantly metabolism genes, whereas virulence factors were mostly controlled by RNAIII. Remarkably, the phenol-soluble modulin (PSM) leukocidin genes were the only virulence determinants under RNAIII-independent control, emphasizing their exceptional role in S. aureus physiology and pathogenesis. Of note, PSM promoters bound the AgrA response regulator protein, previously believed to interact exclusively with agr promoters, explaining the exceptionally strict control of PSMs by agr. Our results suggest that virulence factor control is a secondary acquisition of the agr regulon, which evolved by development of RNAIII around the mRNA of the PSM d-toxin, exemplifying how gene control via a small regulatory RNA may be linked to a pre-established regulatory circuit. In addition to elucidating agr control in CA-MRSA, which revealed features potentially crucial for CA-MRSA pathogenesis, our study establishes a novel two-level model of cell-density dependent gene regulation in S. aureus and gives important insight into the connection of metabolism and virulence control in this leading opportunistic pathogen. Keywords: Wild type control vs mutant Wild type in triplicate is compared to mutant in triplicate totalling 27 samples
2010-05-14 | E-GEOD-10165 | biostudies-arrayexpress
Project description:The quorum-sensing agr system protects Staphylococcus aureus from oxidative stress (5 hour growth)
| PRJNA852568 | ENA
Project description:The Staphylococcus aureus accessory gene regulator (agr) is a prototype quorum-sensing system in Gram-positive bacteria and a paradigmatic example of gene regulation by a small regulatory RNA, RNAIII. Using genome-wide transcriptional profiling in the community-associated methicillin-resistant (CA-MRSA) strain MW2, we demonstrate here that in contrast to the current model of target gene regulation by agr, a large subset of agr-regulated genes is controlled independently of RNAIII. This group comprised predominantly metabolism genes, whereas virulence factors were mostly controlled by RNAIII. Remarkably, the phenol-soluble modulin (PSM) leukocidin genes were the only virulence determinants under RNAIII-independent control, emphasizing their exceptional role in S. aureus physiology and pathogenesis. Of note, PSM promoters bound the AgrA response regulator protein, previously believed to interact exclusively with agr promoters, explaining the exceptionally strict control of PSMs by agr. Our results suggest that virulence factor control is a secondary acquisition of the agr regulon, which evolved by development of RNAIII around the mRNA of the PSM d-toxin, exemplifying how gene control via a small regulatory RNA may be linked to a pre-established regulatory circuit. In addition to elucidating agr control in CA-MRSA, which revealed features potentially crucial for CA-MRSA pathogenesis, our study establishes a novel two-level model of cell-density dependent gene regulation in S. aureus and gives important insight into the connection of metabolism and virulence control in this leading opportunistic pathogen. Keywords: Wild type control vs mutant
2009-01-05 | GSE10165 | GEO
Project description:In many pathogens, quorum-sensing systems regulate virulence. Quorum-sensing is therefore often proposed as a target for antivirulence drug development. Coagulase-negative staphylococci are leading causes of nosocomial blood infections and of mortality due to sepsis as the most extreme consequence of such infections. However, there is a severe lack of understanding how virulence and especially quorum-sensing affects coagulase-negative staphylococcal sepsis. Using a mouse systemic infection model, we here show that the staphylococcal Agr quorum-sensing system has a strong impact on mortality from sepsis caused by the exemplary coagulase-negative staphylococcal species Staphylococcus haemolyticus. To that end, we analyzed the mechanism and regulon of S. haemolyticus Agr, which revealed a strong focus of quorum-sensing regulation of phenol-soluble modulin toxins. Our results further indicate that PSMs are the virtually exclusive mediators of the Agr effect on S. haemolyticus sepsis and suggest that the predominant underlying mechanism is cytolytic capacity of PSMs. These findings imply that Agr and PSMs represent promising targets for antivirulence drug development targeting sepsis caused by coagulase-negative staphylococci. This contrasts quorum-sensing targeted efforts to control S. aureus blood infections, for which such approaches are considered less promising - a difference our results suggest is due to the much more focused role of Agr control in coagulase-negative staphylococci, where among toxins, Agr exclusively and exceptionally tightly controls PSMs.
2025-09-23 | GSE285447 | GEO
Project description:Drug discovery for novel anti-infectives is essential to meet the global health threat of antibiotic resistant bacterial infections, including those caused by Staphylococcus aureus1,2. Because ~90% of S. aureus infections involve skin and soft tissues (SSTIs)3,4, we hypothesized that developing anti-virulence therapeutics5,6 for SSTIs could minimize pressure on resistance development while sparing conventional antibiotics for control of systemic infections. We identified a small molecule inhibitor that disrupted signaling by a quorum sensing operon, agr, associated with human SSTIs7,8 without affecting agr-independent growth.
2017-02-09 | GSE52978 | GEO
Project description:Single-cell approach dissecting agr quorum sensing dynamics in Staphylococcus aureus
| PRJEB72799 | ENA