Project description:Primary objectives: The primary objective is to investigate circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Primary endpoints: circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Project description:Pseudomonas aeruginosa, the type species of the Pseudomonas genus, is an environmental Gram negative bacterium, well-known for its ability to produce toxins, resist antibiotics, and opportunistically colonize various niches, including invertebrate and vertebrate hosts. P. aeruginosa produces redox active secondary metabolites called phenazines involved in quorum sensing, biofilm formation, virulence, and iron acquisition. Moreover, these colorful pigmented virulence factors act as ligands for the highly conserved aryl hydrocarbon receptor (AhR) thereby regulating antibacterial defenses in vertebrates. Pseudomonas spp. are some of the most frequently identified bacteria in larval and adult stages of wild mosquito populations. Here we investigated global transcriptional changes induced in A. coluzzii third instar larvae incubated with a sublethal concentration (50 µM) of 1-hydroxyphenazine (1-HP) or pyocyanin (Pyo) at 4 h and 8 h of continuous incubation by whole-genome DNA microarrays.
Project description:ErfA is a transcription factor of Pseudomonas aeruginosa. We here define the genome-wide binding sites of ErfA by DAP-seq in Pseudomonas aeruginosa PAO1 and IHMA87, Pseudomonas chlororaphis PA23, Pseudomonas protegens CHA0 and Pseudomonas putida KT2440.
Project description:KaiC is the central cog of the circadian clock in Cyanobacteria. Close homologs of this protein are widespread among bacteria not known to have a circadian physiology. The function, interaction network, and mechanism of action of these KaiC homologs are still largely unknown. Here, we focus on KaiC homologs found in environmental Pseudomonas species. We characterize experimentally the only KaiC homolog present in Pseudomonas putida KT2440 and Pseudomonas protegens CHA0. Through phenotypic assays and transcriptomics, we show that KaiC is involved in osmotic and oxidative stress resistance in P. putida and in biofilm production in both P. putida and P. protegens.
Project description:Investigation of whole genome gene expression AdnA in Pseudomonas fluorescens, an ortholog of FleQ in P. aeruginosa, regulates both motility and flagella-mediated attachment to various surfaces. A whole genome microarray determined the AdnA transcriptome by comparing the gene expression pattern of wild-type Pf0-1 to that of Pf0-2x (adnA-) in broth culture. In the absence of AdnA, expression of 92 genes was decreased, while 11 genes showed increased expression. Analysis of 16 of these genes fused to lacZ confirmed the microarray results. Several genes were further evaluated for their role in motility and biofilm formation. Two genes, Pfl01_1508 and Pfl01_1517, affected motility and had different effects on biofilm formation in Pf0-1. These two genes are predicted to encode proteins similar to the glycosyl transferases FgtA1 and FgtA2, which have been shown to be involved in virulence and motility in P. syringae. Three other genes, Pfl01_1516, Pfl01_1572, and Pfl01_1573, not previously associated with motility and biofilm formation in Pseudomonas had similar affects on biofilm formation in Pf0-1. Deletion of each of these genes led to different motility defects. Our data revealed an additional level of complexity in the control of flagella function beyond the core genes known to be required, and may yield insights into processes important for environmental persistence of P. fluorescens Pf0-1.
Project description:We carried out an experimental evolution in human serum as an ex-vivo model and screened evolved lines for the evolution of resistance phenotypes towards two anti-virulence treatments, gallium and flucytosine, which both target the iron scavenging pyoverdine of Pseudomonas aeruginosa (each at 2 different doses). We performed whole-genome sequencing of 16 evolved clones from the different treatment regimes .
Project description:Oberhardt2008 - Genome-scale metabolic
network of Pseudomonas aeruginosa (iMO1056)
This model is described in the article:
Genome-scale metabolic
network analysis of the opportunistic pathogen Pseudomonas
aeruginosa PAO1.
Oberhardt MA, Puchałka J, Fryer
KE, Martins dos Santos VA, Papin JA.
J. Bacteriol. 2008 Apr; 190(8):
2790-2803
Abstract:
Pseudomonas aeruginosa is a major life-threatening
opportunistic pathogen that commonly infects immunocompromised
patients. This bacterium owes its success as a pathogen largely
to its metabolic versatility and flexibility. A thorough
understanding of P. aeruginosa's metabolism is thus pivotal for
the design of effective intervention strategies. Here we aim to
provide, through systems analysis, a basis for the
characterization of the genome-scale properties of this
pathogen's versatile metabolic network. To this end, we
reconstructed a genome-scale metabolic network of Pseudomonas
aeruginosa PAO1. This reconstruction accounts for 1,056 genes
(19% of the genome), 1,030 proteins, and 883 reactions. Flux
balance analysis was used to identify key features of P.
aeruginosa metabolism, such as growth yield, under defined
conditions and with defined knowledge gaps within the network.
BIOLOG substrate oxidation data were used in model expansion,
and a genome-scale transposon knockout set was compared against
in silico knockout predictions to validate the model.
Ultimately, this genome-scale model provides a basic modeling
framework with which to explore the metabolism of P. aeruginosa
in the context of its environmental and genetic constraints,
thereby contributing to a more thorough understanding of the
genotype-phenotype relationships in this resourceful and
dangerous pathogen.
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MODEL1507180020.
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