Project description:Arrays comparing Pseudomonas aeruginosa growth in a defined synthetic cystic fibrosis sputum medium with and without aromatic amino acids. Additional arrays comparing wild-type Pseudomonas aeruginosa and phhR mutant P. aeruginosa in defined synthetic cystic fibrosis sputum medium.
Project description:Cystic fibrosis bronchial epithelial (CFBE41o-ΔF508) cells subjected to 23 bio-active small molecules including vehicle controls, at low temperature and untreated cells. Untreated Cystic fibrosis bronchial epithelial cells (CFBE41o−CFTR) are also included.
Project description:Pseudomonas aeruginosa airway infection is the primary cause of death in Cystic Fibrosis (CF). During early infection P. aeruginosa produces multiple virulence factors, which cause acute pulmonary disease and are largely regulated by quorum sensing (QS) intercellular signalling networks. Longitudinal clinical studies have observed the loss, through adaptive mutation, of QS and QS-related virulence in late chronic infection. Although the mechanisms are not understood, infection with QS mutants has been linked to a worse outcome for CF patients. By comparing QS-active and QS-inactive P. aeruginosa CF isolates, we have identified novel virulence factors and pathways associated with QS disruption. In particular, we noted factors implicating increased intra-phagocyte survival. Our data present novel targets as candidates for future CF therapies. Some of these targets are already the subject of drug development programmes for the treatment of other bacterial pathogens and may provide cross-over benefit to the CF population. Refer to individual Series. This SuperSeries is composed of the following subset Series: GSE25128: Gene expression data from Pseudomonas aeruginosa strains isolated from cystic fibrosis lung infections GSE25129: Comparative genomic hybridisation data from Pseudomonas aeruginosa strains isolated from cystic fibrosis lung infections
Project description:Chronic Pseudomonas biofilm infections are commonly associated in patients afflicted with cystic fibrosis (CF) leading to high degree of morbidity. In a murine tumor model we demonstrated that P. aeruginosa efficiently colonizes and forms biofilms in cancerous tissue post intra-venous injection. Several non-biofilm forming mutants have been identified and incorporated in the present study. Biofilm formation by wild type strains was evident in electron microscopy and immuno-histological studies. Efficacy of currently available CF infection treatment antibiotics such as ciprofloxacin, colistin and tobramycin were tested in this model. We found out that normal doses of these antibiotics were unable to eliminate wild type P. aeruginosa PA14. However, transposon mutants of P. aeruginosa PA14 (pqsA & Pel A) had strong influence on colonization. Subsequently high doses were effective against wild type P. aeruginosa PA14 biofilms.
Project description:Effect of anaerobic growth condition on gene expression profile of Pseudomonas aeruginosa PA14 grown in cystic fibrosis sputum with 100 mM nitrate added
Project description:ndvB is a gene expressed preferrentialy in biofilms of Pseudomonas aeruginosa and has been implicated in antibiotic resistance. This gene also has a role in signaling in some plant pathogens. A knockout ndvB strain was used to determine if it controlled any other gene expression related to antibiotic resistance We used microarrays of wildtype and ndvB knockout P. aeruginosa grown in biofilms to identify the role of ndvB in gene expression Wildtype and ndvB knockout PA14 biofilms were grown for 48 hours followed by RNA extraction. RNA was pooled from 2 wells for each condition to obtain a single biological replicate. Affymetrix microarray processing was performed on PA01 genechips and data analysis was carried out using R statistical framework with bio-conductor packages using RMA and MAS5.0 normalization procedures
Project description:The following describes additional preliminary data to that outlined in Project PXD014022 and specifically describes the 12-hour co-exposure and P. aeruginosa 12 hour exposure preliminary experiments. Aspergillus fumigatus and Pseudomonas aeruginosa are the most prevalent fungal and bacterial pathogens associated with cystic fibrosis-related infections, respectively. P. aeruginosa eventually predominates as the primary pathogen, though it is unknown why this is the case. Label-free quantitative (LFQ) proteomics was employed to characterize the cellular response to co-exposure of A. fumigatus and P. aeruginosa using the type II alveolar epithelial cell line, A549, as a model of the alveolar surface. Proteomic data revealed that P. aeruginosa replication increased exponentially when co-cultured with A. fumigatus. Comparative analysis using LFQ proteomics revealed similarities and distinct differences in the response of A549 cells to A. fumigatus, or P. aeruginosa and sequential exposure to both pathogens. In total, 2264 proteins were identified. Analysis of statistically significant (p<0.05; ±1.5 fold change) differentially abundant (SSDA) proteins, revealed an increase in the relative abundance of proteins associated with biological processes common to all pathogen-exposed groups.
Project description:Analysis of Pseudomonas aeruginosa PA01 (ATCC 15692) Psl polysaccharide deficient mutant. Psl polysaccharide deficient mutant is evaluated with microarray to understand the genes affected by this polysaccharide. Our results provide new vision on the roles played by Psl polysaccharide in P. aeruginosa. Exopolysaccharide Psl is a critical biofilm matrix component in Pseudomonas aeruginosa, which forms a fiber-like matrix to enmesh bacteria communities. Iron has been shown to serve as a signal in P. aeruginosa biofilm development, yet how iron controls biofilm formation is not clear. Here we perform a transcriptomic analysis to compare Psl negative strain versus its isogenic wild-type strain PAO1. The results indicate that the expression of genes involved in iron homeostasis and oxidative stress response increased drastically at transcriptional level in Psl negative strain, suggesting Psl deficiency induces iron limitation. Subsequent studies confirm that Psl can efficiently bind iron in vitro and Psl fibers functions as an iron storage channel in P. aeruginosa biofilms.
Project description:Pseudomonas aeruginosa is an opportunistic human pathogen, infecting immuno-compromised patients and causing persistent respiratory infections in people affected from cystic fibrosis. Pseudomonas strain Pseudomonas aeruginosa PA14 shows higher virulence than Pseudomonas aeruginosa PAO1 in a wide range of hosts including insects, nematodes and plants but the precise cause of this difference is not fully understood. Little is known about the host response upon infection with Pseudomonas and whether or not transcription is being affected as a host defense mechanism or altered in the benefit of the pathogen. In this context the social amoeba Dictyostelium discoideum has been described as a suitable host to study virulence of Pseudomonas and other opportunistic pathogens.
Project description:Pseudomonas aeruginosa (P. aeruginosa) lung infection is a significant cause of mortality in patients with cystic fibrosis (CF). Most CF patients acquire unique P. aeruginosa strains from the environment; however clonal strains have been identified in CF communities in several countries. Two clonal strains infect 10% to 40% of patients in three CF clinics in mainland eastern Australia. The expression profiles of four planktonically-grown isolates of one Australian clonal strain (AES-2), and four non–clonal CF P. aeruginosa isolates were compared to each other and to the reference strain PAO1 using the Affymetrix P. aeruginosa PAO1 genome array, to gain insight into properties mediating the enhanced infectivity of AES-1. The isolates were subsequently grown as 3-day old biofilms and similarly extracted for RNA and compared as above. Data analysis was carried out using BIOCONDUCTOR software. Keywords: Comparative strain hybridization