Mutation of the Streptococcus gordonii Thiol-Disulfide Oxidoreductase SdbA Leads to Enhanced Biofilm Formation Mediated by the CiaRH Two-Component Signaling System
Streptococcus gordonii is a commensal inhabitant of human oral biofilms. Previously, we identified an enzyme called SdbA that played an important role in biofilm formation by S. gordonii. SdbA is thiol-disulfide oxidoreductase that catalyzes disulfide bonds in secreted proteins. Surprisingly, inacti...
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Published in | PloS one Vol. 11; no. 11; p. e0166656 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
Public Library of Science
15.11.2016
Public Library of Science (PLoS) |
Subjects | |
Online Access | Get full text |
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Summary: | Streptococcus gordonii is a commensal inhabitant of human oral biofilms. Previously, we identified an enzyme called SdbA that played an important role in biofilm formation by S. gordonii. SdbA is thiol-disulfide oxidoreductase that catalyzes disulfide bonds in secreted proteins. Surprisingly, inactivation of SdbA results in enhanced biofilm formation. In this study we investigated the basis for biofilm formation by the ΔsdbA mutant. The results revealed that biofilm formation was mediated by the interaction between the CiaRH and ComDE two-component signalling systems. Although it did not affect biofilm formation by the S. gordonii parent strain, CiaRH was upregulated in the ΔsdbA mutant and it was essential for the enhanced biofilm phenotype. The biofilm phenotype was reversed by inactivation of CiaRH or by the addition of competence stimulating peptide, the production of which is blocked by CiaRH activity. Competition assays showed that the enhanced biofilm phenotype also corresponded to increased oral colonization in mice. Thus, the interaction between SdbA, CiaRH and ComDE affects biofilm formation both in vitro and in vivo. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Competing Interests: The authors have declared that no competing interests exist. Conceptualization: LD SH SL. Data curation: LD. Formal analysis: LD. Funding acquisition: SL. Investigation: LD. Methodology: LD SH SL. Project administration: SH SL. Resources: SH SL. Supervision: SH SL. Validation: LD. Visualization: LD. Writing – original draft: LD. Writing – review & editing: LD SH SL. |
ISSN: | 1932-6203 1932-6203 |
DOI: | 10.1371/journal.pone.0166656 |