Chemical composition and antimicrobial activity of the essential oil of oregano (Origanum floribundum Munby.) endemic to northern Algeria

This paper investigated the chemical composition of the essential oil (EO) of Origanum floribundum Munby. by gas chromatography coupled with mass spectrometry and evaluated its antimicrobial activity. The compositional analysis identified 33 compounds representing 97.26% of the total composition, of which the majority component was carvacrol at 41.092%. The antimicrobial activity evaluated deduced that O. floribundum EO affects all tested strains, of which the most susceptible were Staphylococcus aureus and Candida albicans, with growth inhibition zones of 25.83 mm and 23.25 mm, respectively. A bactericidal effect was recorded on Staphylococcus aureus and Bacillus cereus at 1.56 mg/mL and 3.125 mg/mL EO, respectively, and a fungistatic effect on Candida albicans at 1.56 mg/mL of EO. The intestinal microbiota strains, Bifidobacterium animalis subsp lactis and Lactobacillus rhamnosus LbRE-LSAS, were not affected by O. floribundum EO.