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).

2016-02-26 | E-GEOD-44681 | biostudies-arrayexpress

Antibacterial activities of the algal bromophenol methylrhodomelol against Pseudomonas aeruginosa

Project description:Methylrhodomelol (1) is a bromophenol from the red alga Vertebrata lanosa (L.) T.A.Christensen that has been associated with antimicrobial properties. Aim of the current study was therefore, to assess the antimicrobial potential of this compound in more detail against the gram-negative pathogen Pseudomonas aeruginosa. 1 exerted weak bacteriostatic activity against different strains when grown in minimal medium, whereas other phenolics were inactive. In addition, 1 (35 and 10 µg/mL) markedly enhanced the susceptibility of multidrug resistant P. aeruginosa towards the aminoglycoside gentamicin, while it did not affect the viability of Vero kidney cells up to 100 µM. Finally, pyoverdine release was reduced in bacteria treated at sub-inhibitory concentration, but no effect on other virulence factors was observed. Transcriptome analysis of treated versus untreated P. aeruginosa indicated an interference of 1 with bacterial carbon and energy metabolism, which was corroborated by RT-qPCR and decreased ATP-levels in treated bacteria.

2024-04-07 | GSE249483 | GEO

The phage-encoded protein PIT2 impacts bacterial quorum sensing in Pseudomonas aeruginosa by direct interaction with LasR

Project description:Quorum sensing (QS) is the cell density-dependent virulence factor regulator in Pseudomonas aeruginosa. Here, we elucidate PIT2, a phage-encoded inhibitor of the QS regulator LasR, derived from the lytic Pseudomonas phage LMA2. PIT2 inhibits the effectors PrpL and LasA of the type 2 secretion system of P. aeruginosa and attenuates bacterial virulence towards HeLa cells and in Galleria mellonella. Using RNAseq-based differential gene expression analysis, the effect of PIT2 on the LasR regulatory network was revealed. Moreover, the specific interaction between LasR and PIT2 was determined. These data expand our knowledge on phage-encoded modulators of the bacterial metabolism, as this examples an anti-virulence protein derived from a lytic phage. From an applied perspective, this phage protein reveals and exploits an interesting anti-virulence target in P. aeruginosa. As such, it lays the foundation for a new phage-inspired anti-virulence strategy to combat multidrug resistant pathogens and opens the door for SynBio applications.

2023-09-27 | GSE227677 | GEO

Pseudomonas aeruginosa DHS01

Project description:Multidrug-resistant epidemic Pseudomonas aeruginosa genome sequencing (early isolate)

| PRJNA224149 | ENA

Pseudomonas aeruginosa DHS29

Project description:Multidrug-resistant epidemic Pseudomonas aeruginosa genome sequencing (late isolate)

| PRJNA224150 | ENA