ESSENTIAL OILS HAVE GREAT POTENTIAL IN MOUNTING AN OXIDATIVE STRESS RESPONSE IN STAPHYLOXANTHIN PRODUCING STAPHYLOCOCCUS AUREUS

Abstract

S. aureus is an etiological agent that possesses a myriad array of virulence factors (VFs). Staphyloxanthin (STX) is one such VF present in S. aureus that confers protection against reactive oxygen species produced by host defense and allows the bacteria to persist in the inflammation site. These properties make STX an attractive target for antivirulence therapy, as demonstrated for some plant-derived compounds. Essential oils (EOs) are invigorating and rational approaches to combat the complications arising from multidrug-resistant STX producing S. aureus (SPSA). The main objective of this study is to derive novel inferences to effectively determine EOs as antistaphylococcal agents suppressing STX pigment production and activating oxidative stress response in SPSA. From the EOs library, a total of 16 EOs were studied against SPSA isolates, among them, cinnamon (3.125 μL/mL), clove (3.125 μL/mL)), thyme (12.5 μL/mL)), ginger (12.5 μL/mL)), tea tree (12.5 μL/mL)), tulsi (25 μL/mL)), peppermint (25 μL/mL)) and eucalyptus (25 μL/mL)) EO successfully arrests SPSA isolates for inhibiting the production of STX. The inhibitory effects of EOs towards STX production confirmed that S. aureus grown in the presence of EOs showed increased susceptibility to H2O2 and singlet oxygen. Consequently, the survival ability of the EOs treated organism decreased in freshly isolated human whole blood due to less carotenoid pigment to act as an antioxidant scavenger. Furthermore, the statistical analysis of the results established EOs as a significant protection against SPSA where normal probability test, linear correlation, ANOVA, and two sample T-test successfully analyzed at significance α=0.05. Thus the present findings reveal the potential of EOs as an alternative antivirulence candidate to control S. aureus pathogenicity, which may give a new lifeline in this post-antibiotic era.