IADR Abstract Archives

Harnessing Natural Competence in Streptococcus Ferus for Oral Health.

Objectives: The ability to take up and incorporate foreign DNA is a well-known characteristic of naturally transformable Streptococci. The objectives of this work were to identify if the understudied species Streptococcus ferus was also capable of natural transformation, using a system similar to that
identified in Streptococcus mutans. S. mutans natural transformation is under the control of the alternative sigma factor sigX (also known as comX), whose expression is induced by two types of peptide signals: CSP (competence stimulating peptide, encoded by comC) and XIP (sigX-inducing peptide, encoded by comS). These systems control competence via either the two-component signal-transduction system ComDE or the transcriptional regulator ComR, respectively.
Methods: Protein and nucleotide homology searches were used to determine if S. ferus encoded for putative orthologs of comRS and/or comCDE. Synthetic peptides encoding for competence-inducing peptide (XIP) from S. mutans or a putative XIP from S. ferus were added to cultures of S. ferus alongside DNA to determine if S. ferus was able to induce natural competence in response to XIPs. Knockouts of genes identified to be important for S. ferus natural transformation were constructed and assessed for their role in natural transformation. Resulting knockout strains were assessed for biofilm formation and growth defects.
Results: Protein and nucleotide homology searches identified in S. ferus putative orthologs of comRS, but not comCDE. We demonstrate that natural transformation in S. ferus is induced by a small, double-tryptophan containing competence-inducing peptide (XIP), akin to that of S. mutans, and requires the presence of the comR homolog for efficient transformation. Additionally, we find that natural transformation is induced in S. ferus by both the native XIP and the XIP variant of S. mutans.
Conclusions: S. ferus possesses a system for natural transformation similar to that identified in S. mutans. Natural transformation induction in S. ferus by both the native XIP and the XIP variant of S. mutans implies that crosstalk between the two species is possible. This process has been harnessed to construct gene deletions in S. ferus and used to examine the production and biological relevance of tryglysin A, an antimicrobial RaS-RiPP produced by S. ferus.

2022 Pan European Region Oral Health Congress (Marseille, France)
Marseille, France
  • Rued, Britta  ( University of Illinois , Chicago , Illinois , United States )
  • Federle, Michael  ( University of Illinois , Chicago , Illinois , United States )
  • NONE
    NIH, R01-AI091779 to M.J.F. and 5K12 GM139186/NIGMS/NIH to B.E.R.
    Oral Session
    Thursday, 09/15/2022 , 04:00PM - 06:00PM