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:Arginine utilization in Pseudomonas aeruginosa with multiple catabolic pathways represents one of the best examples of metabolic versatility of this organism. To identify genes of this complex arginine network, we employed DNA microarray to analyze the transcriptional profiles of this organism in response to L-arginine. While most genes in arginine uptake, regulation and metabolism have been identified as members of the ArgR regulon in our previous study, eighteen putative transcriptional units of 38 genes including the two known genes of the arginine dehydrogenase (ADH) pathway, kauB and gbuA, were found inducible by exogenous L-arginine but independent of ArgR.
Project description:Arginine utilization in Pseudomonas aeruginosa with multiple catabolic pathways represents one of the best examples of metabolic versatility of this organism. To identify genes of this complex arginine network, we employed DNA microarray to analyze the transcriptional profiles of this organism in response to L-arginine. While most genes in arginine uptake, regulation and metabolism have been identified as members of the ArgR regulon in our previous study, eighteen putative transcriptional units of 38 genes including the two known genes of the arginine dehydrogenase (ADH) pathway, kauB and gbuA, were found inducible by exogenous L-arginine but independent of ArgR. We conducted three independent microarray experiments in the presence (experimental) of L-Glutamate or D-Arginine. P. aeruginosa PAO1 was grown aerobically in minimal medium P with 300 rpm shaking at 37°C, in the presence of L-Glu with or without the addition of D-Arg at 20 mM.
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:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare transcriptome profiling of control of P. aeruginosa PAO1 (RNA-seq) to transcriptome profiling of farnesol-treated P. aeruginosa PAO1 and to evaluate protocols for optimal high-throughput data analysis. Methods:LB medium (50 mL) was inoculated with exponential growth phase P. aeruginosa PAO1 at a concentration of 108 CFU/mL. Farnesol was then added at a concentration of either 0 (control) or 0.56 mg/mL, in triplicate. All six experiment groups were incubated in a water bath shaker at 37 ºC with a shaking rate of 180 rpm for 5 h. Cells were then sampled and centrifuged from the three control groups and three farnesol treatment groups, respectively. The cell precipitates were separately snap-frozen at -80ºC. Total RNA was isolated from cells using Trizol (Life Technologies, USA) according to the manufacturer’s protocol. Results: Our RNA-seq results showed that less than 100 genes of P. aeruginosa PAO1 were differentially expressed following farnesol treatment. We found that about 1.7% of all detected genes (96 of 5554 genes) were more than two-fold differentially expressed following farnesol treatment. Conclusions:
Project description:To further determine the origin of the increased virulence of Pseudomonas aeruginosa PA14 compared to Pseudomonas aeruginosa PAO1, we report a transcriptomic approach through RNA sequencing. Next-generation sequencing (NGS) has revolutioned sistems-based analsis of transcriptomic pathways. The goals of this study are to compare the transcriptomic profile of all 5263 orthologous genes of these nearly two strains of Pseudomonas aeruginosa.
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:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare transcriptome profiling of control of P. aeruginosa PAO1 (RNA-seq) to transcriptome profiling of diallyl disulphide-treated P. aeruginosa PAO1 and to evaluate protocols for optimal high-throughput data analysis. Methods: Every 50 mL LB medium was inoculated exponential growth phase of P. aeruginosa PAO1, with the bacterial concentration of 108 CFU/mL. Then DDS was added, with its concentrations were 0 (as control, three biological repeats numbered A1, A2, and A3) and 0.64 mg/mL (three biological repeats numbered B1, B2, and B3) separately, both with a triplicate. All the six experiment groups were incubated in a water bath shaker at 37 ºC with a shaking rate at 150 rpm for 5 hours. The cells were then sampled and centrifuged from the three control groups and three DDS treatment groups, respectively. The cell precipitates in the control and DDS-treated groups were quickly separately frozen at -80 ºC. Total RNA was isolated from cells using Trizol (Life Technologies, USA) according to the manufacturer’s protocol. Results: The RNA sequencing results revealed that a large number of genes in P. aeruginosa PAO1 were differentially expressed after DDS treatment. More than three thousands of genes were differentially expressed, with either up regulated (1649 genes) or down regulated (1725 genes) more than two-fold. Conclusions:
Project description:Among multiple interconnected pathways for L-Lysine (L-Lys) catabolism in pseudomonads, Pseudomonas aeruginosa PAO1 employed the decarboxylase and the transaminase pathways. However, up till now several genes involved in the operation and regulation of these pathways were still missing. Transcriptome analyses coupled with promoter activity measurements and mutant growth phenotype analysis lead us to identify several new members of the L-Lys and D-Lys catabolic pathways and their regulatory elements, including argR to trigger lysine decarboxylation into cadaverine, PauR for the γ-glutamylation pathway of polyamine catabolism into 5-aminovalerate, gcdR-gcdHG for glutarate utilization, dpkA, amaR-amaAB and PA2035 for D-Lys catabolism, lysR-lysXE for L-Lys efflux, and lysP for L-Lys uptake. Gene expression microarray, including probe preparation, hybridization, fluidics run and chip scan, was performed by Georgia State University DNA/Protein Core Facility. P. aeruginosa PAO1 was grown aerobically in minimal medium P with 350 rpm shaking at 37C, in the presence of 10mM L-glutamate supplemented with 10 mM L-lysine, cadaverine, 5-amino valerate, glutaric acid, D-lysine or 5mM L-pipecolate. Cells were harvested when the optical density at 600 nm reached 0.5~0.6 by centrifugation for 5 minutes at 4C. Total RNA samples were isolated by RNeasy purification kit following instructions of the manufacturer (Qiagen). Reverse transcription for cDNA synthesis, fragmentation by DNase I treatment, cDNA probe labeling and hybridization were performed according to the instructions of GeneChip manufacturer (Affymetrix). Data were processed by Microarray Suite 5.0 software normalizing the absolute expression signal values of all chips to a target intensity of 500. GeneSpring software (Silicon Genetics) was used for expression pattern analysis and comparison. Data collection was carried out using GCOS 1.4 software (Affymetrix). Probe intensity values were normalized to a target value of 500 with normalization factor equal to 1. Data analysis was performed using GeneSpring GX 11 Software (Aglient, Palo Alto,CA). Related Research Papers: 1. Indurthi SM, Chou HT, Lu CD. Molecular Characterization of lysR-lysXE, gcdR-gcdHG, and amaR-amaAB Operons for Lysine Export and Catabolism: A Comprehensive Lysine Catabolic Network in Pseudomonas aeruginosa PAO1. Microbiology. 2015 Submitted [EMID:04803de65c782] 2. Chou HT, Li J, and Lu CD. Functional Characterization of the agtABCD and agtSR Operons for γ-Aminobutyrate and δ-Aminovalerate Uptake and Regulation in Pseudomonas aeruginosa PAO1. Curr. Microbiology. 2014 Jan;68(1):59-63. 3. Chou HT, Li JY, Peng YC, Lu CD. Molecular characterization of PauR and its role in control of putrescine and cadaverine catabolism through the γ-glutamylation pathway in Pseudomonas aeruginosa PAO1. J Bacteriol. 2013 Sep; 195(17):3906-13. 4. Chou HT, Hegazy M, Lu CD. L-lysine Catabolism is Controlled by Arginine/ArgR in Pseudomonas aeruginosa PAO1. J Bacteriol. 2010 Nov;192(22):5874-80