In response to the increasing need for alternative antibacterial agents, we analyzed antibacterial activity of essential oils and hydrosols of five selected medicinal plants: mugwort (Artemisia annua), lavandin (Lavandula hybrida), curry plant (Helichrysum italicum), German chamomile (Matricaria recutita) and sage (Salvia officinalis) against Escherichia coli and Staphylococcus epidermidis. Minimal inhibitory concentration (MIC) was determined using broth microdilution method. Minimal bactericidal concentration (MBC) was confirmed using plate count method. Gram-positive bacteria were more susceptible to essential oils, with most of them having MIC 3.13 mg/ml, while MIC for Gram-negative bacteria were mostly 6.25 mg/ml. Essential oils of lavandin and curry plant were the most effective, followed by mugwort and German chamomile. The sample containing sage essential oil and hydrosol had the most variable results. Essential oils had a better antibacterial effect than hydrosols. At 50 % concentration, hydrosols did not show any inhibition of bacterial growth. At 75 % and 100 % however, antibacterial activity was determined, but only for lavandin hydrosol. Mugwort, curry plant and German chamomile also showed weak antibacterial activity at 100 % concentration, but only against S. epidermidis. Results of our experiments indicate that essential oils and hydrosols of medicinal plants could also be used as antibacterial agents in food industry, which would require further research.
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