A dynamic and intricate regulatory network determines Pseudomonas aeruginosa virulence

Abstract

Pseudomonas aeruginosa is a metabolically versatile bacterium that is found in a wide range of biotic and abiotic habitats. It is a major human opportunistic pathogen causing numerous acute and chronic infections. The critical traits contributing to the pathogenic potential of P. aeruginosa are the production of a myriad of virulence factors, formation of biofilms and antibiotic resistance. Expression of these traits is under stringent regulation, and it responds to largely unidentified environmental signals. This review is focused on providing a global picture of virulence gene regulation in P. aeruginosa. In addition to key regulatory pathways that control the transition from acute to chronic infection phenotypes, some regulators have been identified that modulate multiple virulence mechanisms. Despite of a propensity for chaotic behaviour, no chaotic motifs were readily observed in the P. aeruginosa virulence regulatory network. Having a ‘birds-eye’ view of the regulatory cascades provides the forum opportunities to pose questions, formulate hypotheses and evaluate theories in elucidating P. aeruginosa pathogenesis. Understanding the mechanisms involved in making P. aeruginosa a successful pathogen is essential in helping devise control strategies.

Selection of fast and slow growing bacteria from fecal microbiota using continuous culture with changing dilution rate

“…S-D-Bact-0341-b-S-17 Forward (5´ TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGCCTACGGGNGGCWGCAG) and S-D-Bact-0785-a-A-21 Reverse (5´ GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGGACTACHVGGGTATCTAATCC) were used for PCR amplification of the V3–V4 hypervariable regions of the 16S rRNA genes [29]. The amplified region was 390–410 bp long and average 67,000 reads per sample were obtained.…”

A PhoPQ-Regulated ABC Transporter System Exports Tetracycline in Pseudomonas aeruginosa

“…The high intrinsic resistance of P. aeruginosa also depends on other mechanisms, such as the intrinsic or induced expression of efflux pumps, particularly the nodulation cell division (RND) systems MexAB-OprM and MexXY-OprM, and adaptive production of drug degradation enzymes, such as AmpC ␤-lactamase (4,5). Also of note, metabolic versatility allows P. aeruginosa to adapt to a wide range of environments, including antibiotic stress (6)(7)(8).…”

Pseudomonas Aeruginosa AmpR Transcriptional Regulatory Network

“…In the opportunistic human pathogen P. aeruginosa, gene expression is a tightly controlled process and many regulators act in concert to control virulence traits (511,512).…”

“…P. aeruginosa employs three interdependent mechanisms of QS namely the Las, Rhl and Pseudomonas quinolone system (PQS). The Las system is at the top of the regulatory hierarchy, above the Rhl system, while PQS interacts with both Las and Rhl [reviewed in (511,512)]. In P. aeruginosa, the QS process controls production of secreted enzymes and toxins such as LasA, LasB and ToxA, redox-active compounds such as phenazines (512), and in the case of chronic infections, the formation of bacterial communities called biofilms (451).…”