The inhibitory effect of the methanolic extract and the essence of Anvillea garcinii on expression of the genes related to Staphylococcus aureus biofilm formation.

Background and objectives: Staphylococcus aureus (S. aureus) is a pathogenic bacterium whose virulence is attributed to its extracellular compounds and biofilm-forming ability. This study aimed to evaluate the inhibitory effects of the methanolic extract (AGME) and the essential oil (AGEO) of Anvillea garcinii on the growth and the biofilm formation of S. aureus.

Materials and methods: The antibacterial and antibiofilm activities of AGME and AGEO against S. aureus ATCC 6538 were assessed using the microbroth dilution method and the Crystal Violet Staining Assay, respectively. The expression levels of sarA, spa, and icaA, genes involved in biofilm formation, were analyzed using real-time PCR.

Results: AGME and AGEO inhibited S. aureus growth at minimum inhibitory concentrations (MIC) of 1 mg/ml and 0.6 mg/ml, respectively. AGME exhibited a 72% inhibition of biofilm formation at ¼ MIC, whereas AGEO showed no significant antibiofilm activity. AGME downregulated the expression of sarA, a key regulator of biofilm formation, as well as spa, and icaA genes.

Conclusion: This study demonstrated that A. garcinii essential oil (AGEO) exhibits significant antimicrobial activity, while its methanolic extract (AGME) effectively inhibits biofilm formation in S. aureus. These findings suggest the potential application of AGEO and AGME as antimicrobial and antibiofilm agents. Further investigations on their efficacy against other bacterial pathogens are recommended.