Expression of the hemolytic phospholipase C (PlcH) of Pseudomonas aeruginosa is induced under phosphate starvation conditions or in the presence of the osmoprotectants choline and glycine betaine. Because choline and glycine betaine may serve as carbon and energy sources in addition to conferring osmoprotection to P. aeruginosa, it seemed possible that induction of plcH is subject to catabolite...

The Pseudomonas aeruginosa transcriptional regulator AlgR controls a variety of different processes, including alginate production, type IV pilus function, and virulence, indicating that AlgR plays a pivotal role in the regulation of gene expression. In order to characterize the AlgR regulon, Pseudomonas Affymetrix GeneChips were used to generate the transcriptional profiles of (i) P. aeruginos...

AlgR is a key Pseudomonas aeruginosa transcriptional response regulator required for virulence. AlgR activates alginate production and twitching motility but represses the Rhl quorum-sensing (QS) system, including rhamnolipid production. The role of AlgR phosphorylation is enigmatic, since phosphorylated AlgR (AlgR-P) is required for twitching motility through the fimU promoter but is not requi...

BACKGROUND Pseudomonas aeruginosa lung infections are a huge problem in ventilator-associated pneumonia, cystic fibrosis (CF) and in chronic obstructive pulmonary disease (COPD) exacerbations. This bacterium secretes virulence factors that may subvert host innate immunity. OBJECTIVE We evaluated the effect of P. aeruginosa elastase LasB, an important virulence factor secreted by the type II s...

PURPOSE To determine the importance of Pseudomonas aeruginosa exotoxin A (ETA) as a virulence factor in corneal disease. METHODS Isogenic mutants deficient in ETA were constructed in P. aeruginosa strains PAO1 and ATCC 19660 by allelic exchange and then evaluated for virulence in a mouse model of bacterial keratitis. The effect of ETA on adherence to scarified corneal epithelium was assessed ...

A temperate, type IV pilus-dependent, double-stranded DNA bacteriophage named DMS3 was isolated from a clinical strain of Pseudomonas aeruginosa. A clear-plaque variant of this bacteriophage was isolated. DMS3 is capable of mediating generalized transduction within and between P. aeruginosa strains PA14 and PAO1, thus providing a useful tool for the genetic analysis of P. aeruginosa.

Bacterial adhesion and biofilm formation are both dependent on the production of extracellular polymeric substances (EPS) mainly composed of polysaccharides, proteins, lipids, and extracellular DNA (eDNA). eDNA promotes biofilm establishment in a wide range of bacterial species. In Pseudomonas aeruginosa eDNA is major component of biofilms and is essential for biofilm formation and stability. I...

Two chemotactic transducers for inorganic phosphate (P(i)), designated CtpH and CtpL, have been identified in Pseudomonas aeruginosa. The corresponding genes (ctpH and ctpL) were inactivated by inserting kanamycin and tetracycline resistance gene cassettes into the wild-type genes in the P. aeruginosa PAO1 genome. Computer-assisted capillary assays showed that the ctpH single mutant failed to e...

The opportunistic pathogen Pseudomonas aeruginosa is among the main colonizers of the lungs of cystic fibrosis (CF) patients. We have isolated and sequenced several P. aeruginosa isolates from the sputum of CF patients and compared them with each other and with the model strain PAO1. Phenotypic analysis of CF isolates showed significant variability in colonization and virulence-related traits s...

Studies of immunity to Pseudomonas aeruginosa have indicated that a variety of potential immunogens can elicit protection in animal models, utilizing both antibody- and cell-mediated immune effectors for protection. To attempt to optimize delivery of multiple protective antigens and elicit a broad range of immune effectors, we produced an aroA deletion mutant of the P. aeruginosa serogroup O2/O...