Bacterial resistance to conventional antibiotics necessitates the identification of novel leads for infection control. Interference with extracellular phenomena, such as quorum sensing, extracellular DNA integrity and redox active metabolite release, represents a new frontier to control human pathogens such as Pseudomonas aeruginosa and hence reduce mortality. Here we reveal that the extracellu...

An injury to the skin resulting in a wound starts the complex healing machinery of the body, normally leading to rapid wound closure. In some cases the normal wound healing process is disturbed and prolonged; which can lead to chronic, non-healing wounds such as venous leg ulcers. Chronic wounds in general are estimated to affect 1 – 2 % of the world’s population, and about 1 % is suffering fro...

Background: Pseudomonas aeruginosa is a versatile and opportunistic human pathogen whose virulence derives from several factors as extracellular proteases, pyocyanin and pyoverdin and biofilm formation, among others. Dexamethasone is a glucocorticoid widely used as anti-inflammatory. Despite its immunosuppressive role, the interplay between dexamethasone and bacterial virulence remains uncovere...

Stock pyocyanin at 5 mg/mL in dimethyl sulfoxide was diluted in TSB, TSB agar, and Kings A agar to concentrations from 0 to 100 μM. TSB samples were scanned using square wave voltammetry (SWV) on three separate disposable carbon electrodes three times each from -0.5 to 0.0 V at a frequency and amplitude voltage of 15 Hz and 50 mV, respectively. Agar samples were scanned three times on a single ...

Two seven-gene phenazine biosynthetic loci were cloned from Pseudomonas aeruginosa PAO1. The operons, designated phzA1B1C1D1E1F1G1 and phzA2B2C2D2E2F2G2, are homologous to previously studied phenazine biosynthetic operons from Pseudomonas fluorescens and Pseudomonas aureofaciens. Functional studies of phenazine-nonproducing strains of fluorescent pseudomonads indicated that each of the biosynth...

Secreted virulence factors of the human pathogen Pseudomonas aeruginosa are often under quorum sensing control. Cells lacking the quorum-sensing regulator LasR show reduced virulence factor production under typical laboratory conditions and are hypo-virulent in short-term animal infection models, yet lasR mutants are frequently associated with long-term infection in cystic fibrosis patients. He...

In Pseudomonas aeruginosa, the catabolite repression control (Crc) protein repressed the formation of the blue pigment pyocyanin in response to a preferred carbon source (succinate) by interacting with phzM mRNA, which encodes a key enzyme in pyocyanin biosynthesis. Crc bound to an extended imperfect recognition sequence that was interrupted by the AUG translation initiation codon.

Pyocyanin is an electrochemically active metabolite produced by the human pathogen Pseudomonas aeruginosa. It is a recognized virulence factor and is involved in a variety of significant biological activities including gene expression, maintaining fitness of bacterial cells and biofilm formation. It is also recognized as an electron shuttle for bacterial respiration and as an antibacterial and ...

AIMS Pulmonary infections with Pseudomonas aeruginosa are a serious clinical problem and are often lethal. Because many strains of P. aeruginosa are resistant to antibiotics, therapeutic options are limited. Neutrophils play an important role in the host's early acute defense against pulmonary P. aeruginosa. Therefore, it is important to define the mechanisms by which P. aeruginosa interacts wi...

Antibiotic-sensitive bacteria have been found to coexist with antibiotic-producing bacteria in biofilms, but little is known about how the former develop in such an environment. Here we isolated pyocyanin-sensitive bacteria belonging to the genus Brevibacillus from a biofilm derived from soil extract and based on the preestablished biofilm of a pyocyanin producer, Pseudomonas aeruginosa strain ...