Project description:Pseudomonas aeruginosa is a virulent opportunistic pathogen responsible for high morbity in COPD, burns , implanted medical devices and cystic fibrosis. Pseudomonas aeruginosa is a problematic colonizer of the human lung. P. aeruginosa produces a phospholipase C (PlcH) that degrades choline-containing lipids such as phosphatidylcholine and sphingomylein that are found in lung surfactant and in host membranes. In this study, we analyzed gene expression in mutants defective in PlcH production (delta-plcH and delta-gbdR) and the wild type when growing in medium with lung surfactant. Pseudomonas aeruginosa was cultured in liquid cultures with aeration in a defined medium with Survanta, a lung surfactant replacement. Cultures were harvested during mid-exponential phase, and RNA was isolated for microarray analysis. The P. aeruginosa strain PAO1 wild type gene expression was compared to expression profiles from delta-gbdR and delta-plcHR deletion mutants, two mutants defective in PlcH production.
Project description:The ParS/ParR two component regulatory system plays important roles for multidrug resistance in Pseudomonas aeruginosa. In this study we report RNA-seq analyses of the transcriptomes of P. aeruginosa PAO1 wild type and par mutants growing in a minimal medium containing 2% casamino acids. This has allowed the quantification of PAO1 transcriptome, and further defines the regulon that is dependent on the ParS/ParR system for expression. Our RNA-seq analysis produced the first estimates of absolute transcript abundance for the 5570 coding genes in P. aeruginosa PAO1. Comparative transcriptomics of P. aeruginosa PAO1 and par mutants identified a total of 464 genes regulated by ParS and ParR. Results also showed that mutations in the parS/parR system abolished the expression of the mexEF-oprN operon by down-regulating the regulatory gene mexS. In addition to affecting drug resistance genes, transcripts of quorum sensing genes (rhlIR and pqsABCDE-phnAB), were significantly up-regulated in both parS and parR mutants. Consistent with these results, a significant portion of the ParS/ParR regulated genes belonged to the MexEF-OprN and quorum sensing regulons. Deletion of par genes also lead to overproduction of phenazines and increased swarming motility, consistent with the up-regulation of quorum sensing genes. Our results established a link among ParS/ParR, MexEF-OprN and quorum sensing in Pseudomonas aeruginosa. Based on these results, we propose a model to illustrate the relationship among these regulatory systems in P. aeruginosa. A total of 9 samples were analyzed in AB medium + 2% casamino acids, Pseudomonas aeruginosa PAO1 wild type strain (3 replicates); Pseudomonas aeruginosa parS mutant (3 replicates); Pseudomonas aeruginosa parR mutant (3 replicates).
Project description:The ParS/ParR two component regulatory system plays important roles for multidrug resistance in Pseudomonas aeruginosa. In this study we report RNA-seq analyses of the transcriptomes of P. aeruginosa PAO1 wild type and par mutants growing in a minimal medium containing 2% casamino acids. This has allowed the quantification of PAO1 transcriptome, and further defines the regulon that is dependent on the ParS/ParR system for expression. Our RNA-seq analysis produced the first estimates of absolute transcript abundance for the 5570 coding genes in P. aeruginosa PAO1. Comparative transcriptomics of P. aeruginosa PAO1 and par mutants identified a total of 464 genes regulated by ParS and ParR. Results also showed that mutations in the parS/parR system abolished the expression of the mexEF-oprN operon by down-regulating the regulatory gene mexS. In addition to affecting drug resistance genes, transcripts of quorum sensing genes (rhlIR and pqsABCDE-phnAB), were significantly up-regulated in both parS and parR mutants. Consistent with these results, a significant portion of the ParS/ParR regulated genes belonged to the MexEF-OprN and quorum sensing regulons. Deletion of par genes also lead to overproduction of phenazines and increased swarming motility, consistent with the up-regulation of quorum sensing genes. Our results established a link among ParS/ParR, MexEF-OprN and quorum sensing in Pseudomonas aeruginosa. Based on these results, we propose a model to illustrate the relationship among these regulatory systems in P. aeruginosa.
Project description:Pseudomonas aeruginosa is a virulent opportunistic pathogen responsible for high morbity in COPD, burns , implanted medical devices and cystic fibrosis. Pseudomonas aeruginosa is a problematic colonizer of the human lung. P. aeruginosa produces a phospholipase C (PlcH) that degrades choline-containing lipids such as phosphatidylcholine and sphingomylein that are found in lung surfactant and in host membranes. In this study, we analyzed gene expression in mutants defective in PlcH production (delta-plcH and delta-gbdR) and the wild type when growing in medium with lung surfactant.
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:PsrA, a transcription factor belonging to the TetR family, is known to participate in the regulation of fatty acid metabolism, type III secretion system, and quinolone signaling in Pseudomonas aeruginosa. Using a psrA overexpression strain, this study conducted a transcriptomic analysis to examine the role of PsrA in P. aeruginosa PAO1.
Project description:The gene encoding elongation factor G, fusA1, is frequently mutated in clinical isolates of Pseudomonas aeruginosa from patients with cystic fibrosis. Recent work has shown that fusA1 mutants often display elevated aminoglycoside resistance due to increased expression of the aminoglycoside efflux pump, MexXY. We isolated a spontaneous gentamicin-resistant fusA1 mutant (FusA1-P443L) in which mexXY expression was increased. We compared the proteome of this fusA1 mutant (EMC1) with the P. aeruginosa PAO1-derived progenitor strain (EMC0) and complemented mutant strain expressing the wild-type fusA1 gene in trans (EMC1*).
Project description:The TyrR-like enhancer-binding protein GcsR (or PA2449) was shown to regulate the expression of genes required for glycine metabolism. In order to define the regulon of GcsR we compared the transcriptome of a gcsR deletion mutant of P. aeruginosa PAO1 with that of the wild-type using RNA-Seq.