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The Impact of Pyruvate Oxidase (SpxB) on the Release of the Toxin Pneumolysin in Streptococcus Pneumoniae

Streptococcus pneumoniae (pneumococcus) is a major human pathogen and commensal organism of the nasopharynx. A major virulence factor of the pneumococcus is the cholesterol dependent, pore forming cytolysin pneumolysin. This toxin acts extracellularly, but the mechanism of release has not been well elucidated. Despite being a catalase negative organism, the pneumococcus produces up to millimolar concentrations of hydrogen peroxide through the activity of pyruvate oxidase. In all strains analyzed, deletion of the pyruvate oxidase gene yielded a significant reduction in the amount of PLY observed in the supernatant via western blot. A single strain, WU2 was also observed to have a significant (p<.05) reduction in the amount of PLY observed in the supernatant when treated with extracellular catalase. Furthermore, a significant correlation between hydrogen peroxide production and PLY release was observed in a panel of 15 clinical isolates.

Identiferoai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-5506
Date14 August 2015
CreatorsBryant, Joseph Colby
PublisherScholars Junction
Source SetsMississippi State University
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceTheses and Dissertations

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