Investigation of the effects of chlorhexidine gluconateand lavender essential oil combinati̇ons on methicillinresistant Staphylococus aureus (MRSA) isolates

It is known that MRSA isolates have increased resistance to antiseptic agents as well as antimicrobial drugs. Since the importance of combination therapies against antimicrobial resistance is known to increase in the literature, the combinatorial effects of lavender essential oil (LEO) and chlorhexidine (CHG) compounds, which show antibacterial activity against MRSA isolates, were investigated in this study.In this context, the effect of antimicrobial agents against clinical isolates obtained from the hospital and MRSA and MSSA isolates from the culture collection was evaluated alone and in combination by performing disc diffusion and microdilution tests. The presence of resistance genes (mecA, qac A/B and qacC) was investigated for all isolates and the synergistic effects of the combined compounds were determined by the checkboard test, and their pharmacodynamic properties were determined by the time kill test. According to the results of the disk diffusion test, it was determined that all of the tested agents were effective on the isolates. It was determined that resistance genes were present in all isolates except the MSSA isolate, the combination showed a synergistic effect on all isolates tested according to the checkboard test result and a bactericidal effect within 24 hours against all isolates as a result of the time kill test. This is the first study which evaluates the activity of LEO&CHG combinations against S. aureus isolates. In line with the findings obtained in this context, designing and conducting in vivo studies are expected to significantly contribute to the results of the current study and also to provide the basis of clinical studies.