Project description:Pseudomonas aeruginosa frequently resides among ethanol-producing microbes, making its response to these microbially-produced concentrations of ethanol relevant to understanding its biology. Transcriptome analysis found that the genes involved in trehalose metabolism were induced by low concentrations of ethanol, and levels of intracellular trehalose increased significantly upon growth with ethanol. The increase in trehalose was dependent on the TreYZ pathway, and not other trehalose metabolic enzymes TreS or TreA. The sigma factor AlgU (AlgT), a homolog of RpoE in other species, was required for increased expression of the treZ gene and trehalose levels, but induction was not controlled by the well-characterized proteolysis of its antisigma factor MucA. Growth with ethanol led to increased (p)ppGpp, synthesized by SpoT, and genetic data suggest that increased (p)ppGpp stimulates AlgU-dependent transcription of treZ and other AlgU-regulated genes through DksA, a (p)ppGpp and RNA polymerase binding protein. Ethanol stimulation of trehalose also required acylhomoserine lactone (AHL)-mediated quorum sensing, as induction was not observed in a ∆lasR∆rhlR strain. A network analysis of publicly available P. aeruginosa transcriptome datasets using eADAGE provided strong support for our model that treZ and co-regulated genes are controlled by both AlgU and AHL-mediated QS. Consistent with (p)ppGpp and AHL-mediated quorum sensing regulation, ethanol, even when added at the time of culture inoculation, only stimulated treZ transcript levels and trehalose production in post-exponential phase cultures. These data highlight the integration of growth and cell density cues in responses to ethanol.
Project description:Pseudomonas aeruginosa is an opportunistic pathogen frequently isolated from co-infections with Candida albicans and other ethanol-producing organisms. We found that ethanol, including that produced by C. albicans, stimulates the PhoB regulon in P. aeruginosa. We identify a subset of PhoB-regulated genes as differentially expressed in response to ethanol which are slightly different than the set of genes with increased expression in a genetically induced low phosphate response via pstB mutation.
Project description:Analysis of Pseudomonas aeruginosa PAO1 treated with 200 µM sphingomyelin. Results provide insight into the response to sphingomyelin in P. aeruginosa.
Project description:Pseudomonas aeruginosa PAO1 persister and normal cells were treated with and without Granulocyte Macrophage Colony-Stimulating Factor (GM-CSF) to understand the effect of GM-CSF on gene expression of PAO1. We used DNA microarrays to identify the down-regulated and up-regulated genes after GM-CSF treatment.
Project description:In the present study, we employed Affymetrix Pseudomonas aeruginosa GeneChip arrays to investigate global gene expression profiles during the cellular response of Pseudomonas aeruginosa to sodium hypochlorite Keywords: Antimicrobial response
Project description:Biofilm formation by Pseudomonas aeruginosa relies on specific changes in gene expression. Some of these genes, for instance, control antibiotic resistance. We used microarrays to detail the global programme of gene expression underlying biofilm formation and identified distinct classes of up-regulated genes during this process. Pseudomonas aeruginosa PAO1 cells were grown as planktonic cells in LB broth for 4 hours (PC4) or 24 hours (PC24) and sessile cels for 24 hours.
Project description:This study addresses the impact of zinc limitation on the opportunistic human pathogen, Pseudomonas aeruginosa. Zinc limitation was assessed in the P. aeruginosa PAO1 strain using an isogenic deletion mutant lacking the periplasmic, zinc solute-binding protein, znuA (PA5498). ZnuA delivers bound zinc to its cognate ABC transporter, ZnuBC, for import into the cytoplasm. Our transcriptional analyses revealed P. aeruginosa to possess a multitude of zinc acquisition mechanisms, each of which were highly up-regulated in the zinc-deficient znuA mutant strain. P. aeruginosa also utilized zinc-independent paralogues of zinc-dependent genes to maintain cellular function under zinc limitation. Together, these data reveal the complex transcriptional response and versatility of P. aeruginosa to zinc depletion.
Project description:To investigate the gene expression profile of pellicle cells of Pseudomonas aeruginosa, microarray analysis was performed. Transcriptome profiles of pellicle cells and planktonic cells grown in LB medium were determined by Affymetrix GeneChip. Gene expression pattern that is specific to pellicle cells was evaluated by comparing the data set with that of planktonic cells.
Project description:To investigate the gene expression profile of pellicle cells of Pseudomonas aeruginosa, microarray analysis was performed. Transcriptome profiles of pellicle cells and planktonic cells grown in LB medium were determined by Affymetrix GeneChip. Gene expression pattern that is specific to pellicle cells was evaluated by comparing the data set with that of planktonic cells. Pseudomonas aeruginosa wild type (PAO1ut) strain was cultivated aerobically in LB in Erlenmeyer flasks under static or shaking conditions, and total RNAs were extracted at 24 hours (static culture) and early stationary phase (OD600 = 1.4, shaking culture). The experiment was performed in duplicate independent cultures.