Identification of novel antistaphylococcal hit compounds

Area of Science:

• Microbiology
• Drug Discovery
• Biochemistry

Background:

• Staphylococcus aureus is a leading cause of nosocomial infections and exhibits widespread antibiotic resistance.
• Biofilm formation by S. aureus poses significant challenges for treatment.
• Seryl-tRNA synthetase (SerRS) is a validated drug target for antibacterial development.

Purpose of the Study:

• To identify novel antistaphylococcal agents with antibiofilm activity targeting S. aureus SerRS.
• To evaluate the efficacy of identified compounds against multidrug-resistant S. aureus clinical isolates and biofilms.

Main Methods:

• Molecular docking of previously identified antistaphylococcal compounds into the S. aureus SerRS active site.
• Screening of compounds tested against S. aureus ThrRS for SerRS inhibitory activity.
• Antibacterial and anti-biofilm activity assays, including Minimum Inhibitory Concentration (MIC) determination.

Main Results:

• Seven initial hit compounds with low inhibitory activity against SerRS were identified via molecular docking.
• Six additional SerRS inhibitors were found among compounds previously tested against ThrRS.
• One compound, 3-[N'-(2-hydroxy-3-methoxybenzylidene)hydrazino]-6-methyl-4H-[1,2,4]triazin-5-one, demonstrated significant inhibition of planktonic and biofilm S. aureus growth (MIC 32 µg/mL) and lacked activity against E. coli.

Conclusions:

• A novel compound targeting S. aureus SerRS shows potent anti-biofilm activity.
• This compound is a promising candidate for an antiseptic agent against multidrug-resistant, biofilm-forming S. aureus.
• The findings highlight SerRS as a viable target for developing new strategies against challenging S. aureus infections.