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dc.contributor.authorHassett, Daniel J.
dc.contributor.authorMa, J.-F.
dc.contributor.authorElkins, James D.
dc.contributor.authorMcDermott, Timothy R.
dc.contributor.authorOchsner, Urs A.
dc.contributor.authorWest, Susan E. H.
dc.contributor.authorHuang, Ching-Tsan
dc.contributor.authorFredericks, J.
dc.contributor.authorBurnett, S.
dc.contributor.authorStewart, Philip S.
dc.contributor.authorMcFeters, Gordon A.
dc.contributor.authorPassador, L.
dc.contributor.authorIglewski, Barbara H.
dc.identifier.citationHassett, D. J., Ma, J.-F., Elkins, J. G., McDermott, T. R., Ochsner, U. A., West, S. E. H., Huang, C.-T., Fredericks, J., Burnett, S., Stewart, P. S., McFeters, G., Passador, L., and B. H. Iglewski, "Quorum Sensing in Pseudomonas aeruginosa Controls Expression of Catalase and Superoxide Dismutase Genes and Mediates Biofilm Susceptibility to Hydrogen Peroxide," Molecular Microbiology 34:1082-1093 (1999).en_US
dc.description.abstractQuorum sensing (QS) governs the production of virulence factors and the architecture and sodium dodecyl sulphate (SDS) resistance of biofilm-grown Pseudomonas aeruginosa. P. aeruginosaQS requires two transcriptional activator proteins known as LasR and RhlR and their cognate autoinducers PAI-1 (N-(3-oxododecanoyl)-l-homoserine lactone) and PAI-2 (N-butyryl-l-homoserine lactone) respectively. This study provides evidence of QS control of genes essential for relieving oxidative stress. Mutants devoid of one or both autoinducers were more sensitive to hydrogen peroxide and phenazine methosulphate, and some PAI mutant strains also demonstrated decreased expression of two superoxide dismutases (SODs), Mn-SOD and Fe-SOD, and the major catalase, KatA. The expression of sodA (encoding Mn-SOD) was particularly dependent on PAI-1, whereas the influence of autoinducers on Fe-SOD and KatA levels was also apparent but not to the degree observed with Mn-SOD. β-Galactosidase reporter fusion results were in agreement with these findings. Also, the addition of both PAIs to suspensions of the PAI-1/2-deficient double mutant partially restored KatA activity, while the addition of PAI-1 only was sufficient for full restoration of Mn-SOD activity. In biofilm studies, catalase activity in wild-type bacteria was significantly reduced relative to planktonic bacteria; catalase activity in the PAI mutants was reduced even further and consistent with relative differences observed between each strain grown planktonically. While wild-type and mutant biofilms contained less catalase activity, they were more resistant to hydrogen peroxide treatment than their respective planktonic counterparts. Also, while catalase was implicated as an important factor in biofilm resistance to hydrogen peroxide insult, other unknown factors seemed potentially important, as PAI mutant biofilm sensitivity appeared not to be incrementally correlated to catalase levels.en_US
dc.titleQuorum sensing in pseudomonas aeruginosa controls expression of catalase and superoxide dismutase genes and mediates biofilm susceptibility to hydrogen peroxideen_US
mus.citation.journaltitleMolecular Microbiologyen_US
mus.identifier.categoryEngineering & Computer Scienceen_US
mus.relation.collegeCollege of Engineeringen_US
mus.relation.departmentCenter for Biofilm Engineering.en_US
mus.relation.departmentChemical & Biological Engineering.en_US
mus.relation.departmentChemical Engineering.en_US
mus.relation.universityMontana State University - Bozemanen_US
mus.relation.researchgroupCenter for Biofilm Engineering.en_US
mus.contributor.orcidStewart, Philip S.|0000-0001-7773-8570en_US

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