Antibacterial and anti-virulence mechanisms of Etlingera pavieana extract against Staphylococcus aureus and its efficacy in a food matrix

Abstract

Staphylococcus aureus poses a significant threat to food safety, driving the search for effective antibacterial agents. This study investigated the antibacterial and anti-virulence properties of the ethanolic extract of Etlingera pavieana rhizome (EE) against S. aureus . EE exhibited bactericidal activity with a minimum bactericidal concentration of 4 mg/mL. Targeted chemical analysis quantified p -coumaric acid and 4-methoxycinnamyl p -coumarate as primary non-volatile phenolic markers, alongside estragole (71.37%) as the dominant volatile constituent. Mechanistically, EE induced alterations in the bacterial cell surface, evidenced by a significant reduction in cell surface hydrophobicity, which subsequently inhibited biofilm formation. Furthermore, the extract impaired the staphyloxanthin antioxidant shield, rendering the pathogen hypersensitive to oxidative stress during photodynamic inactivation. To validate these findings in a complex environment, EE was evaluated in a lipid- and protein-rich pork broth model. The extract significantly reduced bacterial populations at a high inoculum (~ 10 5  CFU/mL) and prevented regrowth at a lower inoculum (~ 10 3  CFU/mL) over 72 h. These findings highlight the potential of E. pavieana rhizome extract as a multifaceted antibacterial agent capable of controlling S. aureus growth and attenuating its virulence factors within complex biological matrices.