Natural Transformation of Oral Streptococci by Use of Synthetic Pheromones
The discovery that Streptococcus pneumoniae uses a competence-stimulating peptide (CSP) to induce competence for natural transformation, and that other species of the mitis and the anginosus streptococcal groups use a similar system, has expanded the tools to explore gene function and regulatory pathways in streptococci. Two other classes of pheromones have been discovered since then, comprising the bacteriocin-inducing peptide class found in Streptococcus mutans (also named CSP, although different from the former) and the SigX-inducing peptides (XIP), in the mutans, salivarius, bovis, and pyogenes groups of streptococci. The three classes of peptide pheromones can be ordered from peptide synthesis services at affordable prices, and used in transformation assays to obtain competent cultures consistently at levels usually higher than those achieved during spontaneous competence. In this chapter, we present protocols for natural transformation of oral streptococci that are based on the use of synthetic pheromones, with examples of conditions optimized for transformation of S. mutans and Streptococcus mitis.
Key wordsOral streptococcus Streptococcus mutans Streptococcus mitis Competence Natural transformation Competence-stimulating peptide (CSP) SigX-inducing peptide (XIP)
This work was partially supported by the National Science Foundation, grant no. MCB-1020863, by the Faculty of Dentistry, University of Oslo, and by the Norwegian surveillance system for antibiotic resistance in microbes (Norsk overvåkingssystem for antibiotikaresistens hos mikrober—NORM).
- 7.Mashburn-Warren L, Morrison DA, Federle MJ (2010) A novel double-tryptophan peptide pheromone controls competence in Streptococcus spp. via an Rgg regulator. Mol Microbiol 78589–78606Google Scholar
- 11.Son M, Shields RC, Ahn SJ, Burne RA, Hagen SJ (2015) Bidirectional signaling in the competence regulatory pathway of Streptococcus mutans. FEMS Microbiol Lett 362. Doi: 10.1093/femsle/fnv159
- 16.Stevens KE, Chang D, Zwack EE, Sebert ME (2011) Competence in Streptococcus pneumoniae is regulated by the rate of ribosomal decoding errors. mBio 2:doi: 10.1128/mBio.00071-11