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Abstract

The sil System of Streptococcus anginosus: A Key Factor for Survival in Mixed Cultures †

Institute of Medical Microbiology and Hygiene, Ulm University Hospital, 89081 Ulm, Germany
*
Author to whom correspondence should be addressed.
Presented at the 22nd Lancefield International Symposium on Streptococci and Streptococcal Diseases, Brisbane, Australia, 1–5 June 2025.
Proceedings 2025, 124(1), 24; https://doi.org/10.3390/proceedings2025124024
Published: 28 August 2025
Quorum sensing is a density-dependent form of communication in bacteria. In streptococci, the quorum sensing system sil (streptococcal invasion locus) has been associated with virulence and bacteriocin production [1,2,3]. In this system, the autoinducing peptide SilCR is sensed by histidine kinase SilB, which as a response regulator phosphorylates transcription activator SilA. SilA alters gene expression, causing an increased expression of all sil genes, including silCR. SilCR is excreted and processed by SilD and SilE [1,4]. In Streptococcus anginosus, sil regulates the expression of Angicin, a bacteriocin active against various streptococci, listeria, and enterococci [3].
To further characterize the sil system in S. anginosus, deletion mutants of all sil genes were constructed and investigated for their influence on Angicin production. In most strains, the deletion of any gene led to a loss of antimicrobial activity. While a supplementation with synthetic SilCR restored the inhibitory activity of the silCR deletion mutant, it had no effect on any of the other mutants. To assess the role of sil for bacterial fitness, a sil deletion mutant was compared to the wildtype strain in coculture with rival species. In this setting, the bacteriocin-producing wildtype strain demonstrated a significantly enhanced survival, outperforming the sil deletion mutant.
Our study is the first to functionally characterize the sil system of S. anginosus, highlighting its crucial role in bacteriocin production and intra- and interspecies competition.

Author Contributions

Conceptualization, V.V. and B.S.; methodology, J.F., M.J., A.B., L.H. and V.V.; validation, J.F., M.J., A.B., L.H., V.V. and B.S.; writing—original draft preparation, V.V.; writing—review and editing, B.S.; visualization, V.V.; supervision, B.S.; project administration, B.S.; funding acquisition, B.S. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Upon publication as a full manuscript, the data will be made available.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Hidalgo-Grass, C.; Ravins, M.; Dan-Goor, M.; Jaffe, J.; Moses, A.E.; Hanski, E. A locus of group A Streptococcus involved in invasive disease and DNA transfer. Mol. Microbiol. 2002, 46, 87–99. [Google Scholar] [CrossRef] [PubMed]
  2. Hertzog, B.B.; Kaufman, Y.; Biswas, D.; Ravins, M.; Ambalavanan, P.; Wiener, R.; Angeli, V.; Chen, S.L.; Hanski, E. A Sub-population of Group A Streptococcus Elicits a Population-wide Production of Bacteriocins to Establish Dominance in the Host. Cell Host Microbe 2018, 23, 312–323. [Google Scholar] [CrossRef] [PubMed]
  3. Vogel, V.; Bauer, R.; Mauerer, S.; Schiffelholz, N.; Haupt, C.; Seibold, G.M.; Fändrich, M.; Walther, P.; Spellerberg, B. Angicin, a novel bacteriocin of Streptococcus anginosus. Sci. Rep. 2021, 11, 24377. [Google Scholar] [CrossRef] [PubMed]
  4. Eran, Y.; Getter, Y.; Baruch, M.; Belotserkovsky, I.; Padalon, G.; Mishalian, I.; Podbielski, A.; Kreikemeyer, B.; Hanski, E. Transcriptional regulation of the sil locus by the SilCR signalling peptide and its implications on group A streptococcus virulence. Mol. Microbiol. 2007, 63, 1209–1222. [Google Scholar] [CrossRef] [PubMed]
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MDPI and ACS Style

Vogel, V.; Falk, J.; Jachmann, M.; Bitzer, A.; Herrlich, L.; Spellerberg, B. The sil System of Streptococcus anginosus: A Key Factor for Survival in Mixed Cultures. Proceedings 2025, 124, 24. https://doi.org/10.3390/proceedings2025124024

AMA Style

Vogel V, Falk J, Jachmann M, Bitzer A, Herrlich L, Spellerberg B. The sil System of Streptococcus anginosus: A Key Factor for Survival in Mixed Cultures. Proceedings. 2025; 124(1):24. https://doi.org/10.3390/proceedings2025124024

Chicago/Turabian Style

Vogel, Verena, Jana Falk, Marie Jachmann, Alina Bitzer, Lennart Herrlich, and Barbara Spellerberg. 2025. "The sil System of Streptococcus anginosus: A Key Factor for Survival in Mixed Cultures" Proceedings 124, no. 1: 24. https://doi.org/10.3390/proceedings2025124024

APA Style

Vogel, V., Falk, J., Jachmann, M., Bitzer, A., Herrlich, L., & Spellerberg, B. (2025). The sil System of Streptococcus anginosus: A Key Factor for Survival in Mixed Cultures. Proceedings, 124(1), 24. https://doi.org/10.3390/proceedings2025124024

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