Mini-Tn5-induced mutants with defects in utilization of linear terpenes such as citronellol, geraniol, citronellate and/or geranylate were isolated from Pseudomonas aeruginosa. One mutant was unable to utilize geraniol but showed wild-type growth with the three other acyclic terpenes tested. The Tn5 insertion site of the mutant was determined by DNA sequencing. Comparison with the P. aeruginosa...

Quorum sensing (QS) has been recognized as a general phenomenon in microorganisms and plays an important role in many pathogenic bacteria. In this report, we used the Agrobacterium tumefaciens biosensor strain NT1 to rapidly screen for autoinducer-quenching inhibitors from bacteria. After initial screening 5389 isolates obtained from land and beach soil, 53 putative positive strains were identi...

Bacteria inhabiting biofilms usually produce one or more polysaccharides that provide a hydrated scaffolding to stabilize and reinforce the structure of the biofilm, mediate cell-cell and cell-surface interactions, and provide protection from biocides and antimicrobial agents. Historically, alginate has been considered the major exopolysaccharide of the Pseudomonas aeruginosa biofilm matrix, wi...

Plasmids encoding mercury resistance carried by Pseudomonas aeruginosa PAO1161 and PA103 were found to be involved in regulating the secretion of protease, phospholipase C, and alkaline phosphatase. Previously, mutations in Pseudomonas strains that caused pleiotropic effects on the production of extracellular enzymes were mapped to the bacterial chromosome. We show that pleiotropic changes in e...

Pseudomonas aeruginosa, a gram-negative bacterium of clinical importance, forms more robust biofilm during anaerobic respiration, a mode of growth presumed to occur in abnormally thickened mucus layer lining the cystic fibrosis (CF) patient airway. However, molecular basis behind this anaerobiosis-triggered robust biofilm formation is not clearly defined yet. Here, we identified a morphological...

Objective(s): Pseudomonas aeruginosais a Gram-negative and aerobic rod bacterium that displays mucoid and non-mucoid phenotype. Mucoid strains secrete alginate, which is the main agent of biofilms in chronic P. aeruginosa infections, show high resistance to antibiotics; consequently, the biological disruption of mucoid P. aeruginosa biofilms is an attractive area of study for researchers. Algin...

Although P. aeruginosa is especially dangerous in cystic fibrosis (CF), there is no consensus as to how it kills representative cell types that are of key importance in the lung. This study concerns the acute toxicity of the sequenced strain, PAO1, toward a murine macrophage cell line (RAW 264.7). Toxicity requires brief contact with the target cell, but is then delayed for more than 12 h. None...

Two lipopolysaccharide O-antigen-specific monoclonal antibodies, MA1-8 (an immunoglobulin G1 [IgG1]) and MF15-4 (an IgM), were used to localize the O antigen of the lipopolysaccharide of Pseudomonas aeruginosa PAO1. A protein A-dextran-gold conjugate with an average particle diameter of 12.5 nm was used to label bacterial cells treated with MA1-8, while a second antibody (goat anti-mouse IgM) w...

The refractory nature of Pseudomonas aeruginosa infections is due in part to the presence of specialized cells, termed persisters, within the population. To identify genes involved in P. aeruginosa persister formation, a PAO1 transposon (Tn) library was challenged en masse with 1,000 μg/ml of carbenicillin and was enriched for mutants that were able to survive in the presence of this antibiotic...

BACKGROUND Quorum sensing (QS) plays an important role in the production of virulence factors and pathogenicity in Pseudomonas aeruginosa, and the interruption of QS will be a hopeful pathway to combat bacterial infection. OBJECTIVE In this study, we selected Forsythia suspense (Thunb.) Vahl from traditional Chinese herbal medicines for its anti-QS activity. MATERIALS AND METHODS Anti-QS of...