Transcriptomic and Molecular Docking Analysis Reveal Virulence Gene Regulation-Mediated Antibacterial Effects of Benzyl Isothiocyanate Against Staphylococcus aureus.

Staphylococcus aureus (S. aureus) is a common pathogen that can cause many serious infections. Thus, efficient and practical techniques to fight S. aureus are required. In this study, transcriptomics was used to evaluate changes in S. aureus following treatment with benzyl isothiocyanate (BITC) to determine its antibacterial action. The results revealed that the BITC at subinhibitory concentrations (1/8th MIC) treated group had 94 differentially expressed genes compared to the control group, with 52 downregulated genes. Moreover, STRING analyses were used to reveal the protein interactions encoded by 36 genes. Then, we verified three significant virulence genes by qRT-PCR, including capsular polysaccharide synthesis enzyme (cp8F), capsular polysaccharide biosynthesis protein (cp5D), and thermonuclease (nuc). Furthermore, molecular docking analysis was performed to investigate the action site of BITC with the encoded proteins of cp8F, cp5D, and nuc. The results showed that the docking fraction of BITC with selected proteins ranged from - 6.00 to - 6.60 kcal/mol, predicting the stability of these complexes. BITC forms hydrophobic, hydrogen-bonded, π-π conjugated interactions with amino acids TRP (130), GLY (10), ILE (406), LYS (368), TYR (192), and ARG (114) of these proteins. These findings will aid future research into the antibacterial effects of BITC against S. aureus.