Unravel the antimicrobial action of Aguaribay´s Essential oils (EO) against biofilms and planktonic cells of Staphylococcus aureus.

ANDREA C. CUTRÓ; BORDÓN, ANAHÍ; MARIA SUMAMPA, CORIA; RODRIGUEZ, SERGIO A.; HOLLMANN, AXEL

Rosario

Congreso; L Reunión Anual Sociedad Argentina de Biofisica 2022; 2022

Sociedad Argentina de Biofísica

In previous work, we showed that EO obtained from S. areira leaves has shown antibacterial activity against S. aureus. This activity was accompanied by significant changes in the zeta potential of bacterial and model membranes. To achieve a better understanding of the mechanisms of its antibacterial action, new studies in bacteria cells and liposomes were carried out. In this context, the integrity of S. aureus was evaluated as a function of EO concentration and incubation time by fluorescence microscopy. It was observed an increase in permeability of cells up to 40% for the maximal EO concentration tested, showing a time dependent behavior. On the other hand, studies of the EO effect on the transition temperature of DMPC:DMPG (5:1) liposomes membrane by dynamic scattering light measurement and fluorescence spectroscopy of liposomal doped with laurdan indicated the EO produced changes in lipid membrane packing, increasing the fluidity, reducing the cooperative cohesive interaction between phospholipid and increasing access of water to the interior of the membrane. With the aim to evaluate possible intracellular targets, the potential effect on bacterial genomic DNA and metabolic oxidative stress were also assessed. S. areira EO led to partial degradation of DNA after 24h of incubation and it was capable of inducing oxidative stress at CIM and 2 CIM concentrations. Finally, it was observed that this EO has a biofilm inhibition effect at sub-MIC concentrations and also showed a preformed biofilm eradication effect at all the EO concentrations assayed. The results obtained indicated that EO has several bacteria targets, from the cell surface up to DNA, involved in the antibacterial activity observed, affecting planktonic cells and biofilms.