Genome wide transcriptional analysis of P. aeruginosa PAO1, response to phosphate limitation
Ontology highlight
ABSTRACT: P. aeruginosa PAO1 grown as lawns on Nematode Growth Medium prepared without supplementation (NGM Pi<0.1 mM) has high killing ability against C. elegans, however, no mortality in worms has been observed during 48 hrs when feeding on PAO1 lawns grown on phosphate supplemented full NGM Pi 25 mM, pH 6.0 medium. We used a microarray to define the virulence-related genes in P. aeruginosa grown as lawns in NGM Pi<0.1 mM vs NGM Pi25 mM pH 6.0
Project description:P. aeruginosa PAO1 grown as lawns on Nematode Growth Medium prepared without supplementation (NGM Pi<0.1 mM) has high killing ability against C. elegans, however, no mortality in worms has been observed during 48 hrs when feeding on PAO1 lawns grown on phosphate supplemented full NGM Pi 25 mM, pH 6.0 medium. We used a microarray to define the virulence-related genes in P. aeruginosa grown as lawns in NGM Pi<0.1 mM vs NGM Pi25 mM pH 6.0 All samples for gene expression analysis were prepared in biological triplicate. P. aeruginosa MPAO1 cells collected from lawns grown on NGM/[Pi]25 mM, pH 6.0 or NGM/Pi<0.1 mM were used for RNA isolation. Microarray analysis was performed using Affymetrix P. aeruginosa GeneChips (Affymetrix, Santa Clara, CA) at the University of Chicago Functional Genomics Facility
Project description:During extreme physiological stress, the intestinal tract can be transformed into a harsh environment characterized by regio- spatial alterations in oxygen, pH, and phosphate concentration. When the human intestine is exposed to extreme medical interventions, the normal flora becomes replaced by pathogenic species whose virulence can be triggered by various physico-chemical cues leading to lethal sepsis. We previously demonstrated that phosphate depletion develops in the mouse intestine following surgical injury and triggers intestinal P. aeruginosa to express a lethal phenotype that can be prevented by oral phosphate ([Pi]) supplementation. We used a microarray to define the virulence-related genes in P. aeruginosa grown as lawns on NGM at pH7.5 vs pH6.0 All samples for gene expression analysis were prepared in triplicate. P. aeruginosa MPAO1 cells collected from lawns grown on NGM/[Pi]25 mM, pH 6.0 or NGM/[Pi]25, pH 7.5 were used for RNA isolation as previously described. Microarray analysis was performed using Affymetrix P. aeruginosa GeneChips (Affymetrix, Santa Clara, CA) at the University of Chicago Functional Genomics Facility
Project description:Here we examined virulence activation in Pseudomonas aeruginosa in response to the synthetic kappa opioid agonist U-50, 488 in nutrient poor media where growth conditions are limited and density dependent quorum sensing is not activated. We used a microarray to define the virulence-related genes in P. aeruginosa grown in liquid poor nutrient medium to determine the effect of kappa-opioid receptor agonist on virulence/lethal phenotype All biological samples for gene expression analysis were prepared in triplicate. P. aeruginosa MPAO1 cells collected from liquid culture at 7 hrs of growth in 1.) 0.1xTY medium containing tryptone 1 g/L and yeast extract, 0.5 g/L, or 2.) 0.1xTY+25 mM potassium phosphate buffer, pH 6.0, or 3.) 0.1xTY+200 uM U-50,488, or 4.) 0.1xTY+ 25 mM potassium phosphate buffer, pH 6.0+ 200 uM U-50,488 were used for RNA isolation. Microarray analysis was performed using Affymetrix P. aeruginosa GeneChips (Affymetrix, Santa Clara, CA) at the University of Chicago Functional Genomics Facility
Project description:Pseudomonas aeruginosa is one of the most frequent pathogen dominant in complicated urinary tract infections (UTI). To unravel the adaptation strategies of P. aeruginosa to the conditions in the urinary tract and to define the underlying regulatory network an artificial growth system mimicking the conditions in the urinary tract was established. Transcriptome analyses were used to investigate the physiological status of P. aeruginosa under this conditions. We performed comparisons to identify genes induced under artificial urinary tract conditions to unravel the adaptive strategies and the underlying regulatory network used by Pseudomonas aeruginosa during urinary tract infections using Affimetrix GeneChips. Pseudomonas aeruginosa wild type strain PAO1 was grown in an artificial in vitro growth system mimicking the conditions in the urinary tract. Therefore, biofilms were grown on the surface of membrane filters placed on agar plates at 37 °C up to the late logarithmic state under aerobic and anaerobic conditions (incubated in an anaerobic beanch). An artificial urine medium (AUM) simulating the averaged urine of an human adult was used as nutrient souce. 10-fold diluted Luria Bertani (LB)-medium was used as reference medium. For growth under oxygen depletion the media were supplemented with 50 mM KNO3 to sustain anaerobic respiration. The biofilms were harveted at this time points and resuspsended in 0.9% (w/v) NaCl. The OD578 of biofilm suspension was 0.8 for all tested conditions. First comparison: Identification of genes induced or repressed under aerobic conditions in the P. aeruginosa wild type PAO1. Here we compared the transcriptome profile of P. aeruginosa PAO1 grown aerobically for 18 h to the late logarithmic phase in biofilms on AUM with the transcriptome profile of the PAO1 strain, which was grown aerobically for 18 h to the late logarithmic phase in biofilms on 10-fold diluted LB. Second comparison: Identification of genes induced or repressed under anaerobic conditions in the P. aeruginosa wild type PAO1. Here we compared the transcriptome profile of P. aeruginosa PAO1 grown anaerobically for 2 days up to the late logarithmic phase in biofilms on AUM supplemented with 50 mM nitrate with the transcriptome profile of the PAO1 strain, which was grown anaerobically for 2 days up to the late logarithmic phase in biofilms on 10-fold diluted LB supplemented with 50 mM nitrate.
Project description:Pseudomonas aeruginosa (P. aeruginosa) lung infection is a significant cause of mortality in patients with cystic fibrosis (CF). Existing experimental data in our lab showed significantly different levels of virulence of "early" and "late" P. aeruginosa infection isolates in a C. elegans slow killing model. We wished to examine the expression profile of these isolates in order to explore genes that may be responsible for the observed differences. The expression profiles of two pairs of isolates (four isolates in total) were compared to each other using the Affymetrix P. aeruginosa PAO1 genome array, to gain insight into properties mediating virulence in these isolates. Data analysis was carried out using BIOCONDUCTOR software. Keywords: Comparative strain hybridization Two pairs of isolates (four isolates in total) were compared to each other when grown on Nematode Growth Medium (NGM).
Project description:The transcriptome of P. aeruginosa PAO1 in the presence of extracelluar 2-oxoglutarate at a concentration of 20 mM. We determined the transcriptional response of P. aeruignosa PAO1 to extracellular 2-oxoglutarate. P. aeruginosa PAO1 was grown in nutrient broth (Oxoid number 2) and induced with 20 mM 2-oxoglutarate. At 30 min post induction, total RNA was isolated and prepped for Affymetrix GeneChips.
Project description:Pseudomonas aeruginosa PAO1 contacted with and without poplar roots gene expression Poplar contacted with and without PAO1 gene expression. All samples cultured in 1 x hrp + 0.25 % sucrose Experiment Overall Design: Strains: P. aeruginosa PAO1 WT Experiment Overall Design: Medium: 1 x hrp + 0.25 % sucrose Experiment Overall Design: Biofilm grown on poplar root compared to biofilm grown on glasswool Experiment Overall Design: Poplar roots grown
Project description:Gene expression profiles of Bacillus subtilis strain AG174 were compared as a function of steady-state external pH during growth with aeration. Aerated overnight cultures were diluted 1:500 and incubated in 250 mL baffled flasks containing potassium-modified Luria-Bertani medium (LBK) buffered with 50 mM HOMOPIPES at pH 6.0, pH 7.0, and pH 9.0. Tubes were incubated at 37°C with aeration (260 rpm) to an optical density at 600 nm of 0.2. For each of the three pH conditions, RNA was isolated from five independent cultures. Overnight cultures were diluted 1:500 and incubated in 250 mL baffled flasks containing potassium-modified Luria-Bertani medium (LBK) buffered with 50 mM HOMOPIPES at pH 6.0, pH 7.0, and pH 9.0. Cultures were incubated at 37°C with aeration (260 rpm) to an optical density at 600 nm of 0.2. Five replicate cultures were grown at each pH.