Sigma factors are master regulators of bacterial transcription which direct gene expression of specific subsets of genes. In particular, alternative sigma factors are well-known to be key players of bacterial adaptation to changing environments. To elucidate the regulatory network of sigma factors in P. aeruginosa, an integrative approach including sigma factor-dependent mRNA profiling was performed to define the primary regulon of each sigma factor. Overall design: Sigma factor hyper-expressing strains harboring the sigma factor gene in trans under control of the araBAD promoter and sigma factor deletion mutants were constructed. Under optimal conditions regarding sigma factor activity and optional induction of sigma factor expression, bacteria were harvested and total RNA was extracted. Upon mRNA enrichment, RNA was fragmented and ligated to specific RNA-adapters containing a hexameric barcode sequence for multiplexing. These RNA-libraries were reverse transcribed and amplified resulting in cDNA libraries which were sequenced on Illumina platforms. Sequence reads were separated according to their barcodes and barcode sequences were removed. The short reads were mapped to the genome sequence of the reference strain P. aeruginosa PA14 wild-type using stampy with default settings. The R package DESeq was used for differential gene expression analysis.
Antisense transcription in Pseudomonas aeruginosa.
Disease, Subject
View SamplesWe analyzed the transcriptional profile of P.aeruginosa PA14 grown under 14 different environmental conditions. These included conditions of growth within biofilms, at various temperatures, osmolarities and phosphate concentrations, under anaerobic conditions, attached to a surface and conditions encountered within the eukaryotic host. We found that >30% of the PA14 genome was differentially regulated at least under one of the 14 environmental conditions (referred to as the adaptive transcriptome). Most of the genes were also differentially regulated upon sigma factor hyper expression and/or inactivation (GEO accession number GSE54999) and many of those belonged to primary alternative sigma factor regulons. Overall design: The samples of P. aeruginosa PA14 wild type strain were cultivated under 14 different experimental conditions and were analyzed by RNA-seq. For each condition, at least two biological replicates were generated Please note that PA14 is our standard lab strain used for all generated data in this records. There is no mutation introduced for any of those experiments, and thus, the descriptions only highlight the growth conditions.
Antisense transcription in Pseudomonas aeruginosa.
Cell line, Subject
View SamplesExperimental Design
Quorum-sensing antagonistic activities of azithromycin in Pseudomonas aeruginosa PAO1: a global approach.
No sample metadata fields
View SamplesWe demonstrate that the versatile environmental bacterium Pseudomonas aeruginosa adapts a virulence phenotype after serial passage in Galleria mellonella as an invertebrate model host. The virulence phenotype was not linked to the acquisition of genetic variations and was sustained for several generations, despite cultivation of the ex vivo virulence-adapted P. aeruginosa cells under non-inducing rich medium conditions. Transcriptional reprogramming seemed to be induced by a host-specific food source as reprogramming was also observed upon cultivation of P. aeruginosa in medium supplemented with polyunsaturated long-chain fatty acids. Methods : mRNA profiles were generated for Pseudomonas aerugionsa samples derived from LB-cultures grown to an OD600 =2. The removal of ribosomal RNA was performed using the Ribo-Zero Bacteria Kit (Illumina) and cDNA libraries were generated with the ScriptSeq v2 Kit (Illumina) . The samples were sequenced in single end mode on an Illumina HiSeq 2500 device and mRNA reads were trimmed and mapped to the NC_008463.1 (PA14) reference genome from NCBI using Stampy pipeline with defaut settings. Overall design: Isolate CH2658 was subjected to in vivo and in vitro evolution experiments in this study. This isolate was obtained from the lab of G. Gastmeier, Charite Berlin, Germany. The in vivo passages (using G. mellonella) are named CH2658 I-IV corresponding to passages 1 4. The last passage CH2658 IV corresponds to the “evolved strain” and was passaged in LB (four days, two passages a day) to generate revertants which are referred to as CH2658 Rev1-4 corresponding to samples from day1-4. The last passage CH2658 Rev4 is called “revertant”. Additionally, the clinical isolate was passaged under in vitro conditions in the presence of linolenic acid (Roth) with (CH2658 Lil+P) and without paraffin (CH2658 Lil). As controls, CH2658 was passaged in LB (CH2658 LB) and in LB supplemented with paraffin (CH2658 LB+P). The in vitro passage experiment was conducted for four days and two passages a day.
Establishment of an induced memory response in Pseudomonas aeruginosa during infection of a eukaryotic host.
Subject
View SamplesGene regulation via transcription factors influences the metabolic, adaptive and pathogenic capabilities of the organism. We report the transcriptomes of the mutants of six major P. aeruginosa PA14 trancription factors - RhlR, LasR, Anr, GacA, FleQ and CbrB. Overall design: The P. aeruginosa PA14 transposon mutants were analyzed by RNA-seq. All samples were cultivated in LB medium until reaching an OD600 of 2.0. For each biological replicate, three cultures were pooled for RNA extraction, library preparation and sequencing.
Functional modules of sigma factor regulons guarantee adaptability and evolvability.
Subject
View SamplesPurpose: The goal of this study was to use RNA Seq to explore whether and to what extent genetic heterogeneity would shape the transcriptional profile in the environment of the CF lung Methods : mRNA profiles were generated for Pseudomonas aerugionsa samples derived from explanted lung tissue or pure cultures isolated from the same lung regions by deep sequencing. To enrich the bacterial RNA MicrobeEnrich Kit (Ambion) was used. The removal of ribosomal RNA was performed using the Ribo-Zero Bacteria Kit (Illumina) and cDNA libraries were generated with the ScriptSeq v2 Kit (Illumina) . The samples were sequenced in single end mode on an Illumina HiSeq 2500 device and mRNA reads were trimmed and mapped to the PAO1 NC_002516 reference genome from NCBI using Stampy pipeline with defaut settings. Overall design: mRNA profiles either from Pseudomonas aeruginosa containing explanted lung tissue from a single patient from various regions of the lung or pure P. aeruginosa liquid cultures grown in LB at 37C from the same lung regions as the ex vivo samples were generated and deep sequenced using Illumina HiSeq 2500.
Genetically diverse Pseudomonas aeruginosa populations display similar transcriptomic profiles in a cystic fibrosis explanted lung.
Subject
View SamplesPurpose : The goal of this study was to use RNA-seq to compare transcriptional profiles under biofilm conditions with planktonic growth and explore the correlation of gene expression of a collection of clinical P. aeruginosa isolates to various phenotypes, such as biofilm structure or virulence. Methods : mRNA profiles were generated for Pseudomonas aeruginosa clinical samples derived from various geographical locations by deep sequencing. The removal of ribosomal RNA was performed using the Ribo-Zero Bacteria Kit (Illumina) and cDNA libraries were generated with the ScriptSeq v2 Kit (Illumina). The samples were sequenced in single end mode on an Illumina HiSeq 2500 device or paired end mode on an Illumina Novaseq 6000. mRNA reads were trimmed and mapped to the NC_008463.1 (PA14) reference genome from NCBI using bowtie2 with default settings. Overall design: mRNA profiles from Pseudomonas aeruginosa derived from static biofilm cultures grown for 12h to 48h in 96-well microtiter plates or planktonic LB cultures grown to an OD600 = 2 and deep sequenced using Illumina HiSeq 2500/NovaSeq 6000.
Parallel evolutionary paths to produce more than one <i>Pseudomonas aeruginosa</i> biofilm phenotype.
Subject
View SamplesPurpose : The goal of this study was to use RNA Seq to explore the correlation of gene expression of a collection of clinical P. aeruginosa isolates to various phenotypes, such as antimicrobial resistance, biofilm formation or virulence Methods : mRNA profiles were generated for Pseudomonas aerugionsa clinical samples derived from various geographical locations by deep sequencing. The removal of ribosomal RNA was performed using the Ribo-Zero Bacteria Kit (Illumina) and cDNA libraries were generated with the ScriptSeq v2 Kit (Illumina) . The samples were sequenced in single end mode on an Illumina HiSeq 2500 device and mRNA reads were trimmed and mapped to the NC_008463.1 (PA14) reference genome from NCBI using Stampy pipeline with defaut settings. Overall design: mRNA profiles from Pseudomonas aeruginosa derived from liquid LB cultures grown to an OD600 = 2 and deep sequenced using Illumina HiSeq 2500.
Predicting antimicrobial resistance in Pseudomonas aeruginosa with machine learning-enabled molecular diagnostics.
Disease, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MEK inhibitors activate Wnt signalling and induce stem cell plasticity in colorectal cancer.
Specimen part, Treatment
View SamplesBackground Small colony variants (SCVs) are slow-growing bacteria, which often show increased resistance to antibiotics and cause latent or recurrent infections. It is therefore important to understand the mechanisms at the basis of this phenotypic switch. Methodology/Principal findings One SCV (termed PAO-SCV) was isolated, showing high resistance to gentamicin and to the cephalosporine cefotaxime. PAO-SCV was prone to reversion as evidenced by emergence of large colonies with a frequency of 10-5 on media without antibiotics while it was stably maintained in presence of gentamicin. PAO-SCV showed a delayed growth, defective motility, and strongly reduced levels of the quorum sensing Pseudomonas quinolone signal (PQS). Whole genome expression analysis further suggested a multi-layered antibiotic resistance mechanism, including simultaneous over-expression of two drug efflux pumps (MexAB-OprM, MexXY-OprM), the LPS modification operon arnBCADTEF, and the PhoP-PhoQ two-component system. Conversely, the genes for the synthesis of PQS were strongly down-regulated in PAOSCV. Finally, genomic analysis revealed the presence of mutations in phoP and phoQ genes as well as in the mexZ gene encoding a repressor of the mexXY and mexABoprM genes. Only one mutation occurred only in REV, at nucleotide 1020 of the tufA gene, a paralog of tufB, both encoding the elongation factor Tu, causing a change of the rarely used aspartic acid codon GAU to the more common GAC, possibly causing an increase of tufA mRNA translation. High expression of phoP and phoQ was confirmed for the SCV variant while the revertant showed expression levels reduced to wild-type levels. Conclusions By combining data coming from phenotypic, gene expression and proteome analysis, we could demonstrate that resistance to aminoglycosides in one SCV mutant is multifactorial including overexpression of efflux mechanisms, LPS modification and is accompanied by a drastic down-regulation of the Pseudomonas quinolone signal quorum sensing system.
Phenotypic and genome-wide analysis of an antibiotic-resistant small colony variant (SCV) of Pseudomonas aeruginosa.
No sample metadata fields
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