19 research outputs found
Analysis of the pressure perturbation due to the introduction of a measuring probe under an elastic garment
Anionic fluoroquinolones as antibacterials against biofilm-producing Pseudomonas aeruginosa
A proteome analysis of the response of a Pseudomonas aeruginosa oxyR mutant to iron limitation
Nanowires and nanostructures fabrication using template methods: a step forward to real devices combining electrochemical synthesis with lithographic techniques
Pseudomonas aeruginosa AlgR Phosphorylation Modulates Rhamnolipid Production and Motility
Mext Functions as a Redox-responsive regulator modulating disulfide stress resistance in Pseudomonas aeruginosa
MexT is a global LysR transcriptional regulator known to modulate antibiotic resistance and virulence in Pseudomonas aeruginosa. In this study, a novel role for MexT in mediating intrinsic disulfide stress resistance was demonstrated, representing the first identified phenotype associated with inactivation of this regulator in wild-type cells. Disruption of mexT resulted in increased susceptibility to the disulfide stress elicitor diamide [diazenedicarboxylic acid bis(N,N,-di-methylamide)]. This compound is known to elicit a specific stress response via depletion of reduced glutathione and alteration of the cellular redox environment, implicating MexT in redox control. In support of this, MexT-regulated targets, including the MexEF-OprN multidrug efflux system, were induced by subinhibitory concentrations of diamide. A mexF insertion mutant also exhibited increased diamide susceptibility, implicating the MexEF-OprN efflux system in MexT-associated disulfide stress resistance. Purified MexT protein was observed to form an oligomeric complex in the presence of oxidized glutathione, with a calculated redox potential of −189 mV. This value far exceeds the thiol-disulfide redox potential of the bacterial cytoplasm, ensuring that MexT remains reduced under normal physiological conditions. MexT is activated by mutational disruption of the predicted quinone oxidoreductase encoded by mexS. Alterations in the cellular redox state were observed in a mexS mutant (PA14nfxC), supporting a model whereby the perception of MexS-associated redox signals by MexT leads to the induction of the MexEF-OprN efflux system, which, in turn, may mediate disulfide stress resistance via efflux of electrophilic compounds
The Stringent Response Controls Catalases in Pseudomonas aeruginosa and Is Required for Hydrogen Peroxide and Antibiotic Tolerance
Formation of Pseudomonas aeruginosa PAO1 biofilms in the presence of hydrogen peroxide. The effect of the aiiA gene
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Development of Potent Inhibitors of Pyocyanin Production in Pseudomonas aeruginosa
The development of new approaches for the treatment of antimicrobial-resistant infections is an urgent public health priority. The Pseudomonas aeruginosa pathogen, in particular, is a leading source of infection in hospital settings, with few available treatment options. In the context of an effort to develop antivirulence strategies to combat bacterial infection, we identified a series of highly effective small molecules that inhibit the production of pyocyanin, a redox-active virulence factor produced by P. aeruginosa. Interestingly, these new antagonists appear to suppress P. aeruginosa virulence factor production through a pathway that is independent of LasR and RhlR