A Staphylococcus aureus Virulence Inhibitor Identified by SaeRS Refactoring and Screening in Bacillus subtilis

Authors

Felix Ekness, Ph.D. program in Systems, Synthetic, and Physical Biology, Rice University, Houston, Texas 77005, United States.
Eric A. Wold, Department of Bioengineering, Rice University, Houston, Texas 77005, United States.
Catherine S. Leasure, Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee 37235, United States.
Elena Musteata, Ph.D. program in Systems, Synthetic, and Physical Biology, Rice University, Houston, Texas 77005, United States.
Andrew J. Monteith, Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee 37235, United States.
Clare Laut, Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee 37235, United States.

Document Type

Article

Publication Date

4-18-2025

Journal Title

ACS synthetic biology

MeSH Headings

Bacillus subtilis (genetics, metabolism, drug effects); Bacterial Proteins (genetics, metabolism, antagonists & inhibitors); Staphylococcus aureus (drug effects, pathogenicity, genetics, metabolism); Virulence (drug effects); Anti-Bacterial Agents (pharmacology); Signal Transduction (drug effects); Histidine Kinase (metabolism, genetics, antagonists & inhibitors); Gene Expression Regulation, Bacterial (drug effects); Phosphorylation (drug effects); Small Molecule Libraries (pharmacology); Protein Kinases; Transcription Factors

Abstract

Bacteria utilize two-component system (TCS) signal transduction pathways to sense environmental and physiological stimuli and mount appropriate responses. In opportunistic pathogens such as Staphylococcus aureus, TCSs activate virulence programs in response to host defense systems. Due to their critical role in pathogenesis, TCSs are important targets for antivirulence drug discovery campaigns. However, challenges associated with screening TCSs in pathogens and in vitro have limited the output of such efforts to a small number of characterized drug candidates. Here, we functionally express the S. aureus virulence-regulating TCS SaeRS from synthetic gene regulatory elements in the model bacterium Bacillus subtilis to reliably screen this system against a small molecule library under simple culturing conditions. Our approach reveals the compound NSC97920 as a strong inhibitor of SaeRS signaling. We combine in situ, in vivo, in silico, and in vitro characterization to demonstrate that NSC97920 suppresses the critical step of autophosphorylation in the SaeS histidine kinase, resulting in strong antivirulence activity. Our work shows that heterologous expression and screening of TCSs in model bacteria could accelerate the development of therapeutics against antibiotic-resistant pathogens.

First Page

1191

Last Page

1203

Recommended Citation

Ekness, Felix; Wold, Eric A.; Leasure, Catherine S.; Musteata, Elena; Monteith, Andrew J.; and Laut, Clare, "A Staphylococcus aureus Virulence Inhibitor Identified by SaeRS Refactoring and Screening in Bacillus subtilis" (2025). MaineHealth Maine Medical Center. 3985.
https://knowledgeconnection.mainehealth.org/mmc/3985