The Antibacterial Activity of Lavender Essential Oil Alone and In Combination with Octenidine Dihydrochloride against MRSA Strains

Abstract

In the post-antibiotic era the issue of bacterial resistance refers not only to antibiotics themselves but also to common antiseptics like octenidine dihydrochloride (OCT). This appears as an emerging challenge in terms of preventing staphylococcal infections, which are both potentially severe and easy to transfer horizontally. Essential oils have shown synergisms both with antibiotics and antiseptics. Therefore the aim of this study was to investigate the impact of lavender essential oil (LEO) on OCT efficiency towards methicillin-resistant S. aureus strains (MRSA). The LEO analyzed in this study increased the OCT’s susceptibility against MRSA strains. Subsequent FTIR analysis revealed cellular wall modifications in MRSA strain cultured in media supplemented with OCT or LEO/OCT. In conclusion, LEO appears to be a promising candidate for an efficient enhancer of conventional antiseptics.

Antibacterial Activity of Selected Essential Oil Compounds Alone and in Combination with β-Lactam Antibiotics Against MRSA Strains

“…Interestingly, at 1220 cm −1 and 1080 cm −1 , the higher intensity in MRSA isolates (with high-level methicillin (MIC = 1000 ± 0.0 mg/L) and penicillin G (MIC ≥ 31.3 ± 0.0 mg/L) resistance strains) can be attributed to the symmetric and asymmetric PO 2 − stretching vibrations in phosphodiester groups, present, among others, in teichoic acid/lipoteichoic acid of Gram-positive bacteria [ 31 ]. The above-mentioned changes may affect the electrostatic interactions with antibacterial molecules, as also proven in our previous studies [ 11 , 13 ]. Moreover, blaR1 protein (which is involved in sensing of the β-lactam antibiotics and then transduction of the information to the cell’s interior) may play an important role in the association with -OH groups [ 32 ].…”

“…Nevertheless, LEO is recommended for the treatment of many skin infections caused by S. aureus such as carbuncles, abscesses, and wounds [ 27 ]. Moreover, our other previous studies showed synergism between LEO and octenidine dihydrochloride against MRSA strains [ 13 ]. Taking that fact into account, linalyl acetate was chosen for the current study.…”

“…Spectroscopic tools not only provide competitive and rapid identification methods, but also allow investigating microorganisms in their intact state. These also appear to be very promising tools to study microbial metabolism, antibiotic susceptibility, and other interactions with drugs [ 11 , 13 , 30 ]. Special attention was paid to the analysis of bands correlated with structures present in the MRSA cell wall (e.g., peptidoglycan layer).…”

“…FTIR spectroscopy analyses were conducted using staphylococcal colonies as described in our previous studies [ 11 , 13 ]. Briefly, after overnight culturing of strains at 37 °C, grown colonies were transferred directly to the Eppendorf tube, washed three times using PBS, and adjusted to 1.2 × 10 9 CFU/mL.…”

“…According to the literature data, monoterpene derivatives from plants have antistaphylococcal potential [ 10 , 11 ]. Moreover, it is known that the combination of secondary metabolites with antimicrobial agents can show synergistic or additive effects; thus, it is possible to use these combinations to reduce the effective dose of chemical antimicrobials and antiseptic agents [ 12 , 13 ].…”