Dataset Information

Hypoxia decreases the pathogenicity of Pseudomonas aeruginosa by reducing expression of multiple virulence factors.

ABSTRACT: Hypoxia is a feature of the microenvironment during P. aeruginosa infection in several disease states. We confirm that the pathogenicity of P. aeruginosa derived from sites of acute infection is higher than those derived from sites of chronic infection. Hypoxia attenuated the pathogenicity of acute but not chronic strains implicating a role for hypoxia in controlling virulence. Mass spectrometric analysis revealed reduced expression of multiple virulence factors in hypoxia including exotoxin A, alkaline protease and proteins important in the synthesis of pyoverdine. Inhibition of pyoverdine production by iron supplementation mimicked the effects of hypoxia. Finally, strains of P. aeruginosa which lacks a functional pseudomonas prolyl-hydroxylase domain containing protein (PPHD) do not respond to hypoxia implicating a possible role for PPHD as an oxygen-sensing determinant of pathogenicity. Understanding how hypoxia influences bacterial virulence will identify new targets for anti–infective therapy against P. aeruginosa.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Pseudomonas Aeruginosa Str. E2uos

SUBMITTER: Alex von kriegsheim

LAB HEAD: Alex von Kriegsheim

PROVIDER: PXD004421 | Pride | 2017-06-06

REPOSITORIES: Pride

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Publications

Hypoxia Reduces the Pathogenicity of Pseudomonas aeruginosa by Decreasing the Expression of Multiple Virulence Factors.

Schaible Bettina B Rodriguez Javier J Garcia Amaya A von Kriegsheim Alexander A McClean Siobhán S Hickey Caitríona C Keogh Ciara E CE Brown Eric E Schaffer Kirsten K Broquet Alexis A Taylor Cormac T CT

The Journal of infectious diseases 20170501 9

Our understanding of how the course of opportunistic bacterial infection is influenced by the microenvironment is limited. We demonstrate that the pathogenicity of Pseudomonas aeruginosa strains derived from acute clinical infections is higher than that of strains derived from chronic infections, where tissues are hypoxic. Exposure to hypoxia attenuated the pathogenicity of strains from acute (but not chronic) infections, implicating a role for hypoxia in regulating bacterial virulence. Mass spe ...[more]

PMID: 28368464

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Project description:One of the hallmarks of Pseudomonas aeruginosa cystic fibrosis (CF) infection is very high-cell-density (HCD) replication in the lung, allowing this bacterium to induce virulence controlled by HCD quorum-sensing systems. However, the nutrient sources sustaining HCD replication in this chronic infection is largely unknown. Hence, understanding the nutrient factors contributing to HCD in the CF lung will yield new insights into the 'metabolic pathogenicity' and potential treatment of CF infections caused by P. aeruginosa. Herein, we performed microarray studies of P. aeruginosa directly isolated from the CF lung to demonstrate its metabolic capability and virulence in vivo. Our in vivo microarray data, confirmed by real-time reverse-transcription-PCR, indicated P. aeruginosa expressed several genes for virulence, drug-resistance, and utilization of multiple nutrient sources (lung surfactant lipids and amino acids) contributing to HCD replication. The data also indicates deregulation of several pathways, suggesting in vivo evolution by deregulation of a large portion of the transcriptome during chronic CF infection. To our knowledge, this is the first in vivo transcriptome of P. aeruginosa in a natural CF infection, and it indicates several important aspects of pathogenesis, drug-resistance, and nutrient-utilization never before observed in vivo. Experiment Overall Design: The purpose of the experiment was to observe which genes are upregulated in P. aeruginosa during chronic CF lung infection as compared to PAO1. All in vitro studies were grown in 1x M9 minimal media supplemented with 20 mM citrate and grown to mid-log phase prior to RNA isolation. The in vivo RNA was isolated directly from CF sputum samples after TRIzol treatment. Each in vitro sample (both for PAO1 and the CF sputum pool isolate) were processed individually and in triplicate. Two in vivo isolations from sputum were conducted from the same patient but two different sputum samples. After isolation of total RNA, samples were processed for microarrays (i.e. cDNA synthesis, fragmentation, labeling, etc) as recommended by Affymetrix, and processed on the GeneChip as recommended by Affymetrix.

Dataset Information

Hypoxia decreases the pathogenicity of Pseudomonas aeruginosa by reducing expression of multiple virulence factors.

Publications

Hypoxia Reduces the Pathogenicity of Pseudomonas aeruginosa by Decreasing the Expression of Multiple Virulence Factors.

Similar Datasets

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