Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR20281310_1.fastq.gz | Fastqsanger.gz | |||
| SRR20281310_2.fastq.gz | Fastqsanger.gz | |||
| SRR20281311_1.fastq.gz | Fastqsanger.gz | |||
| SRR20281311_2.fastq.gz | Fastqsanger.gz | |||
| SRR20281312_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Panton-valentine leukocidin (PVL) has been linked to worldwide emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) -- its role in virulence in unclear. Here we show that PVL had no effect on global gene expression of prominent CA-MRSA strains nor did it affect bacterial clearance from lungs, spleen and kidneys in a highly discriminatory rabbit bacteremia model. These findings negate a large body of epidemiological research that implicated PVL in CA-MRSA virulence. Keywords: mutant vs wild type in 2 different growth phases grown in 2 different medias
2008-09-12 | GSE8677 | GEO
Project description:Panton-valentine leukocidin (PVL) has been linked to worldwide emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) -- its role in virulence in unclear. Here we show that PVL had no effect on global gene expression of prominent CA-MRSA strains nor did it affect bacterial clearance from lungs, spleen and kidneys in a highly discriminatory rabbit bacteremia model. These findings negate a large body of epidemiological research that implicated PVL in CA-MRSA virulence. Keywords: mutant vs wild type in 2 different growth phases grown in 2 different medias Wild type USA 300 (strain SF8300), wild type USA 400 (strain MW2) were compared against their respective PVL isogenic knock out strains. Strains were compared at both mid-exponential and stationary phase and grown in both TSB and CCY to determine if PVL plays a role in gene regulation under these conditions.
2010-06-19 | E-GEOD-8677 | biostudies-arrayexpress
Project description:The Staphylococcus aureus Panton Valentine leukocidin (PVL) is a pore-forming toxin secreted by strains epidemiologically associated with the current outbreak of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and with the often lethal necrotizing pneumonia. To investigate the role of PVL in pulmonary disease, we tested the pathogenicity of clinical isolates, isogenic PVL-negative and PVL-positive S. aureus strains, as well as purified PVL, in a mouse acute pneumonia model. Here we show that PVL is sufficient to cause pneumonia and that the expression of this leukotoxin induces global changes in transcriptional levels of genes encoding secreted and cell-wall-anchored staphylococcal proteins, including the lung inflammatory factor staphylococcal protein A (Spa). Keywords: comparative transcription profile in the presence or absence of PVL toxin
2007-02-13 | GSE6985 | GEO
Project description:Comparing two subclones (Taiwan clone and Asian-Pacific clone) of CA-MRSA ST59. The Taiwan clone carries the Panton-Valentine leukocidin (PVL) genes, the staphylococcal chromosomal cassette mec (SCCmec) VT and is frequently isolated from patients with severe disease. The Asian-Pacific clone is PVL-negative, carries SCCmec IV, and is a frequent colonizer of healthy children.
2012-05-31 | E-MEXP-3627 | biostudies-arrayexpress
Project description:Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are often caused by strains encoding Panton-Valentine leukocidin (PVL). PVL can cause lysis of polymorphonuclear leukocytes (PMNs) and other myeloid cells in vitro, a function considered widely as the primary means by which PVL might contribute to disease. However, at sublytic concentrations PVL can function as a PMN agonist. To better understand this phenomenon, we investigated the ability of PVL to alter human PMN function. PMNs exposed to PVL had enhanced capacity to produce superoxide in response to N-formyl-methionyl-leucyl-phenylalanine (fMLF), but unlike priming by lipopolysaccharide, this response did not require Toll-like receptor signal transduction. On the other hand, there was subcellular redistribution of NADPH oxidase components in PMNs following exposure of these cells to PVL - a finding consistent with priming. Priming of PMNs with other agonists such as IL-8 or GM-CSF altered the ability PVL to cause formation of pores in the plasma membranes of these cells. Microarray analysis revealed significant changes in the human PMN transcriptome following exposure to PVL, including up-regulation of molecules that regulate the inflammatory response. Consistent with the microarray data, mediators of the inflammatory response were released from PMNs after stimulation with PVL. We conclude that exposure of human PMNs to sublytic concentrations of PVL elicits a proinflammatory response that is regulated in part at the level of gene expression. We propose that PVL-mediated priming of PMNs enhances the host innate immune response.
2012-09-06 | GSE33939 | GEO
Project description:Staphylococcus aureus can cause a broad spectrum of diseases that vary widely in clinical presentation and disease severity[121]. Methicillin-Resistant S. aureus (MRSA) strains first described in the 1960’s[122] were hospital acquired (HA MRSA), however in the 1990’s, community-associated MRSA strains (CA MRSA) were identified and are considered to be more virulent[16]. Therapeutics and management of MRSA focuses on novel antibacterials and vaccines targeting virulence factors. To date no clinical trials for vaccines have succeeded[123] due to the poor understanding of the pathogenic mechanisms exhibited by S.aureus.We investigated the differential gene expression of four clinical MRSA strains in vitro, belonging to HA and CA MRSA, at the stationary and exponential growth phases, using RNA-seq on the Ion torrent next generation sequencing platform. This study reveals the high diversity of virulence trait expression among MRSA strains within strains as well as between different growth phases, and also suggests potential factors other than PVL that contributes to enhanced virulence in CA MRSA
2020-01-07 | GSE70636 | GEO
Project description:Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are often caused by strains encoding Panton-Valentine leukocidin (PVL). PVL can cause lysis of polymorphonuclear leukocytes (PMNs) and other myeloid cells in vitro, a function considered widely as the primary means by which PVL might contribute to disease. However, at sublytic concentrations PVL can function as a PMN agonist. To better understand this phenomenon, we investigated the ability of PVL to alter human PMN function. PMNs exposed to PVL had enhanced capacity to produce superoxide in response to N-formyl-methionyl-leucyl-phenylalanine (fMLF), but unlike priming by lipopolysaccharide, this response did not require Toll-like receptor signal transduction. On the other hand, there was subcellular redistribution of NADPH oxidase components in PMNs following exposure of these cells to PVL - a finding consistent with priming. Priming of PMNs with other agonists such as IL-8 or GM-CSF altered the ability PVL to cause formation of pores in the plasma membranes of these cells. Microarray analysis revealed significant changes in the human PMN transcriptome following exposure to PVL, including up-regulation of molecules that regulate the inflammatory response. Consistent with the microarray data, mediators of the inflammatory response were released from PMNs after stimulation with PVL. We conclude that exposure of human PMNs to sublytic concentrations of PVL elicits a proinflammatory response that is regulated in part at the level of gene expression. We propose that PVL-mediated priming of PMNs enhances the host innate immune response. time series of PMN's non treated vs PVL treated vs iPVL treated
2012-09-06 | E-GEOD-33939 | biostudies-arrayexpress
Project description:Introduction Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are increasingly isolated, with USA300-0114 being the predominant clone in the USA. Comparative whole genome sequencing of USA300 isolates collected in 2002, 2003 and 2005 showed a limited number of single nucleotide polymorphisms and regions of difference. This suggests that USA300 has undergone rapid clonal expansion without great genomic diversification. However, whole genome comparison of CA-MRSA has been limited to isolates belonging to USA300. The aim of this study was to compare the genetic repertoire of different CA-MRSA clones with that of HA-MRSA from the USA and Europe through comparative genomic hybridization (CGH) to identify genetic clues that may explain the successful and rapid emergence of CA-MRSA. Materials and Methods Hierarchical clustering based on CGH of 48 MRSA isolates from the community and nosocomial infections from Europe and the USA revealed dispersed clustering of the 19 CA-MRSA isolates. This means that these 19 CA-MRSA isolates do not share a unique genetic make-up. Only the PVL genes were commonly present in all CA-MRSA isolates. However, 10 genes were variably present among 14 USA300 isolates. Most of these genes were present on mobile elements. Conclusion The genetic variation present among the 14 USA300 isolates is remarkable considering the fact that the isolates were recovered within one month and originated from a confined geographic area, suggesting continuous evolution of this clone. Data is also available from <ahref=http://bugs.sgul.ac.uk/E-BUGS-108 target=_blank>BuG@Sbase</a>
2011-04-15 | E-BUGS-108 | biostudies-arrayexpress
Project description:Panton-Valentine Leukocidin (PVL) is a Staphylococcus aureus toxin that binds to and kills human neutrophils resulting in the formation of neutrophil extracellular traps. A subset of individuals colonized with PVL expressing S. aureus suffer from recurring infections. We found that neutrophils from affected individuals display increased spontaneous NET formation after isolation, and increased sensitivity to killing by PVL. Compared to healthy controls, the expression of the target receptors for PVL, CD45 and C5L2, but not CD88, was increased in these patients, and the expression correlated to the amount of PVL-induced NETs produced. NADPH-oxidase activity was not important for PVL induced NETosis as neutrophils from CGD patients produced NETs in response to PVL. Through NET proteome analysis we identified that the protein content of PVL induced NETs is different from mitogen induced NETs. The abundance of the antimicrobial proteins LL37, myeloperoxidase, azurocidin, and proteinase 3 was lower on PVL NETs and PVL-induced NETs were deficient in killing Staphylococcus aureus. Neutrophils from patients that suffer from recurring PVL-positive infections may be more sensitive to PVL-induced NETosis, impairing their ability to combat the infection.
2023-11-23 | PXD025702 | Pride
Project description:Background: Community-associated methicillin-resistant staphylococcus aureus (CA-MRSA) is a drug-resistant bacterium prevalent in community settings, characterized by high pathogenicity and transmission potential. Polymorphonuclear neutrophils (PMNs) represent the first line of defense in innate immunity and are activated to phagocytose MRSA. However, MRSA, once phagocytosed by PMNs, induces necroptosis within the neutrophils, which is a key mechanism contributing to host damage.CA-MRSA releases virulence factors that enhance its pathogenicity by disrupting the host's innate immune response, particularly impairing the phagocytic function of PMNs. Steamed Panax notoginseng (S-PN) has demonstrated immune-regulatory and anti-inflammatory properties, showing promising therapeutic effects in alleviating the severe inflammatory responses induced by pathogenic microbial infections. Objective: This study aims to investigate the pharmacological effects and mechanisms of S-PN in attenuating CA-MRSA-induced necroptosis of PMNs, and to explore the impact of PMN necroptosis on the inflammatory response. Methods: A co-culture model of MRSA USA300 strain and PMNs isolated from healthy human blood was established to observe the changes in necroptosis marker HMGB1, PMNs counts, ROS, chemokine MCP-1 and pro-inflammatory cytokines IL-1β, IL-8, TNF-α. RNA-seq was employed to analyze the effects of S-PN on the transcriptional expression of pathogenesis-related genes of MRSA. RT-PCR was utilized to validate the expression of S-PN on MRSA virulence factors and PMNs necroptosis related genes. Results: S-PN significantly inhibited HMGB1, ROS, MCP-1, IL-1β and IL-8 in MRSA-PMN co-cultures, the PMN count in the S-PN group was higher than that in the model group. S-PN down-regulated MRSA pathogenic-associated Staphylococcus aureus infection and quorum sensing signaling pathways, and significantly reduced the virulence factors PSM and PVL. S-PN suppressed the expression of genes associated with necroptosis ripk1, ripk3, and mlkl in PMNs. Conclusion: S-PN inhibited CA-MRSA-induced necroptosis of PMNs, as well as the excessive inflammatory response and ROS accumulation accompanying this process. The mechanism involves the inhibition of the expression of MRSA virulence factor PSM and necroptosis pathway genes. These findings underscore the significant potential of S-PN in the treatment of CA-MRSA infections.
2025-03-19 | GSE284429 | GEO