Enhancing the antimicrobial sensitivity of Staphylococcus aureus with herbal extracts as an adjunctive treatment for reversing antibiotic resistance

Abstract Background and aim: Staphylococcus aureus is a significant public health concern due to its ability to develop antibiotic resistance. Biofilm formation or the enhancement of bacterial cell membrane permeability contributes to antibiotic resistance ability. Herbal therapy presents a promising strategy to overcome antibiotic resistance challenges. This study aims to investigate the potential of herbal extracts to reverse antibiotic resistance in S. aureus. Experimental Procedure: In this study, both Wild-type and Kanamycin-adapted (Km-adapted) S. aureus strains were pre-treated with herbal extracts derived from Zingiber zerumbet (ZZ), Eucalyptus globulus (EG), Andrographis paniculata (AP), Clerodendrum inerme(CI), Combretum quadrangular (CQ), and Plectranthus amboinicus (PA) at subinhibitory concentrations. The effects of these extracts on biofilm formation, bacterial cell surface hydrophobicity, cell permeability, and kanamycin sensitivity on pre-treated S. aureus were evaluated. Results: Our results demonstrated that S. aureus formed thick biofilms that were less sensitive to Km treatment, particularly in Km-adapted strains. However, extracts from ZZ, EG, and AP effectively reduced biofilm formation in both wild-type and Km-adapted strains and decreased bacterial cell surface hydrophobicity. Additionally, all herbal extracts increased the permeability of S. aureus cells, resulting in enhanced antibiotic sensitivity. Conclusion: Herbal therapy has the potential to reverse antibiotic resistance and reduce the necessary antibiotic dosage for treating S. aureus-related infections.