Testosterone (a strongly hydrophobic steroid) and testosterone hemisuccinate (a negatively charged derivative) were used as probes to investigate alterations in the outer membrane of Pseudomonas aeruginosa. Diffusion rates of the steroids across the lipid bilayer were measured by coupling the influx of these compounds to their subsequent oxidation by an intracellular delta1-dehydrogenase enzyme...

Tn501 random mutagenesis was applied to the Pseudomonas aeruginosa wild-type strain PAO1 to select for mutants hypersusceptible to aminoglycoside antimicrobial agents. One such mutant, called 19A, was found to be hypersusceptible to a wide range of antibiotics including aminoglycosides, beta-lactams, fluoroquinolones, colistin, erythromycin, rifampin, and glycopeptides. Light microscopy of the ...

Quorum sensing (QS) is a system of stimuli and responses in bacterial cells governed by their population density, through which they regulate genes that control virulence factors and biofilm formation. Despite considerable research on QS and the discovery of new antibiotics, QS-controlled biofilm formation by microorganisms in clinical settings has remained a problem because of nascent drug res...

Objective(s):The inhibitory effects of iron chelators, and FeCl3 chelation on biofilm formation and swarming motility were investigated against an opportunistic human pathogen Pseudomonas aeruginosa. Materials and Methods:The inhibitory activity of 2,2’-bipyridyl, lipoic acid, kojic acid and picolinic acidonbiofilm formation of P. aeruginosa strain PAO1 and three clinical isolates (P. aeruginos...

OBJECTIVES The inhibitory effects of iron chelators, and FeCl3 chelation on biofilm formation and swarming motility were investigated against an opportunistic human pathogen Pseudomonas aeruginosa. MATERIALS AND METHODS The inhibitory activity of 2,2'-bipyridyl, lipoic acid, kojic acid and picolinic acid on biofilm formation of P. aeruginosa strain PAO1 and three clinical isolates (P. aerugin...

BACKGROUND The enzymatic degradation of quorums sensing (QS) molecules (called quorum quenching, QQ) has been considered as a promising anti-virulence therapy to treat biofilm-related infections and combat antibiotic resistance. The recently-discovered QQ enzyme MomL has been reported to efficiently degrade different N-acyl homoserine lactones (AHLs) of various Gram-negative pathogens. Here we ...

S-type pyocins are bacteriocins produced by Pseudomonas aeruginosa isolates to antagonize or kill other strains of the same species. They have a modular organization comprising a receptor-binding domain recognizing a surface constituent of the target bacterium, a domain for translocation through the periplasm, and a killing or toxic domain with DNase, tRNase, or pore-forming activity. Pyocins S...

INTRODUCTION Antibiotics are used to treat bacterial infections by killing the bacteria or inhibiting their growth, but resistance to antibiotics can develop readily. The discovery that bacterial quorum-sensing regulates bacterial virulence as well as the formation of biofilms opens up new ways to control certain bacterial infections. Furanone compounds capable of inhibiting bacterial quorum-se...

Pseudomonas aeruginosa is a highly versatile opportunistic pathogen capable of colonizing multiple ecological niches. This bacterium is responsible for a wide range of both acute and chronic infections in a variety of hosts. The success of this microorganism relies on its ability to adapt to environmental changes and re-program its regulatory and metabolic networks. The study of P. aeruginosa a...

Much of the morbidity and mortality in patients with cystic fibrosis (CF) is secondary to pulmonary infections with Pseudomonas aeruginosa and, more recently, with Pseudomonas cepacia. Prevention of colonization and subsequent infection would be a useful therapeutic strategy. The pili (fimbriae) of P. aeruginosa are a potential vaccine antigen, as they have been implicated in binding to respira...