Staphylococcus aureus is an opportunistic pathogen that can lead to a number of potentially terrible community- and hospital-acquired illnesses. Among the diverse set of virulence factors that S. aureus possesses, secreted toxins play a particularly preeminent role in defining its virulence. In this work, we aimed to facilitate the development of novel strategies utilizing natural compounds to lower S. aureus's toxin production and consequently enhance therapeutic approaches. Two natural polyphenols, resveratrol (RSV) and curcumin (CUR), were tested for their effect on reducing toxin gene production of MRSA isolates. Fifty clinical MRSA isolates were gathered from Riyadh and Jeddah. Molecular screening of toxin genes (sea, seb, sec, sed, seh, lukF, and lukS) harbored by MRSA was performed. Sub-inhibitory concentrations of RSV (50 μg/ml) and CUR (20 μg/ml) were determined to study their effect on the gene expression MRSA's toxin genes. Our findings revealed the presence of the tested genes in MRSA isolates, with lukF being the most prevalent gene and seh the least detected gene. We found that RSV reduced the relative expression of toxin genes, sea, seb, lukF, and lukS, respectively, while CUR decreased the relative expression of sea and seb genes in the examined isolates. Regarding lukF and lukS, CUR downregulated the expression of both genes in some isolates and upregulated the expression in other isolates. From these results, we concluded that RSV and CUR could be used as alternative therapeutic approaches to treat MRSA infections through reducing toxin production.
Keywords: Methicillin-Resistant Staphylococcus aureus (MRSA); Staphylococcus aureus; curcumin; gene expression; resveratrol; toxins.