Restoring susceptibility to beta-lactam antibiotics in methicillin-resistant Staphylococcus aureus.
Nguyen, V.T., Birhanu, B.T., Miguel-Ruano, V., Kim, C., Batuecas, M., Yang, J., El-Araby, A.M., Jimenez-Faraco, E., Schroeder, V.A., Alba, A., Rana, N., Sader, S., Thomas, C.A., Feltzer, R., Lee, M., Fisher, J.F., Hermoso, J.A., Chang, M., Mobashery, S.(2024) Nat Chem Biol 
- PubMed: 39060390 
- DOI: https://doi.org/10.1038/s41589-024-01688-0
- Primary Citation of Related Structures:  
8C0P, 8C0S, 8CF3 - PubMed Abstract: 
Infections by Staphylococcus aureus have been treated historically with β-lactam antibiotics. However, these antibiotics have become obsolete in methicillin-resistant S. aureus by acquisition of the bla and mec operons. The presence of the β-lactam antibiotic is detected by the sensor domains of BlaR and/or MecR, and the information is transmitted to the cytoplasm, resulting in derepression of the antibiotic-resistance genes. We hypothesized that inhibition of the sensor domain would shut down this response system, and β-lactam susceptibility would be restored. An in silico search of 11 million compounds led to a benzimidazole-based hit and, ultimately, to the boronate 4. The X-ray structure of 4 is covalently engaged with the active-site serine of BlaR. Compound 4 potentiates by 16- to 4,096-fold the activities of oxacillin and of meropenem against methicillin-resistant S. aureus strains. The combination of 4 with oxacillin or meropenem shows efficacy in infected mice, validating the strategy.
Organizational Affiliation: 
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.