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

first_page Download PDF settings Order Article Reprints Font Type: Arial Georgia Verdana Font Size: Aa Aa Aa Line Spacing:    Column Width:    Background: Open AccessAbstract The sil System of Streptococcus anginosus: A Key Factor for Survival in Mixed Cultures † by Verena VogelVerena Vogel SciProfiles Scilit Preprints.org Google Scholar *, Jana FalkJana Falk SciProfiles Scilit Preprints.org Google Scholar , Marie JachmannMarie Jachmann SciProfiles Scilit Preprints.org Google Scholar , Alina BitzerAlina Bitzer SciProfiles Scilit Preprints.org Google Scholar , Lennart HerrlichLennart Herrlich SciProfiles Scilit Preprints.org Google Scholar and Barbara SpellerbergBarbara Spellerberg SciProfiles Scilit Preprints.org Google Scholar 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 (This article belongs to the Proceedings of The 22nd Lancefield International Symposium on Streptococci and Streptococcal Diseases (LISSSD 2025)) Download keyboard_arrow_down Download PDF Download PDF with Cover Download XML Download Epub Versions Notes Keywords: Streptococcus anginosus; streptococcal invasion locus; competition 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 ContributionsConceptualization, 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.FundingThis research received no external funding.Institutional Review Board StatementNot applicable.Informed Consent StatementNot applicable.Data Availability StatementUpon publication as a full manuscript, the data will be made available.Conflicts of InterestThe authors declare no conflict of interest.ReferencesHidalgo-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]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. 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MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Share and Cite 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 Article Metrics No No Article Access Statistics Multiple requests from the same IP address are counted as one view.