Abstract
Aim: The main purpose of our study is that Geranium essential oil obtained from Pelargonium graveolens plant is combined with ciprofloxacin, a quinolone antibiotic used in the treatment of infections, to reveal its antimicrobial effects against pathogenic microorganisms, which are common nosocomial infections, in an in vitro experimental model.
Methods: Antimicrobial activity of combinations of P. graveolens essential oil with antibiotic (ciprofloxacin) against Staphylococcus aureus and Escherichia coli was determined by the minimum inhibition concentration (MIC) detection method. The bactericidal effects of geranium oils and antibiotics were dynamically demonstrated by the time-dependent killing method of the samples. When geranium oil is used alone or in combination with ciprofloxacin, bacterial outer membrane damage was analyzed by U.V spectrophotometer at 625 nm wavelength.
Results A synergistic effect was observed between essential oil and essential oil+antibiotic combinations. Geranium+ciprofloxacin combination showed ∼87% and ∼78% reduction in E. coli and S. aureus proliferation, respectively. In the time-dependent determination of bacterial cell count, at 24 hours, the combination of ciprofloxacin + geranium was found to reduce the number of living cells, while the use of geranium and ciprofloxacin alone did not show complete destruction of cells compared to the combination. For E. coli and S. aureus, higher bactericidal membrane damage was observed in the groups where ciprofloxacin was used together with geranium oil than the other groups.
Conclusion: In this study, the antimicrobial effect of geranium oil, ciprofloxacin, and its combination were compared. Accordingly, the combination of ciprofloxacin + geranium oil was found to be more effective than both geranium oil and ciprofloxacin.