SONIA TANASESCU, RAZVAN NITU, GEORGE DAHMA, CIPRIAN PILUT, MIRCEA DIACONU, OCTAVIAN NEAGOE, DELIA MUNTEAN, IOANA DELIA HORHAT, ADRIANA DRAGOMIR, DIANA LIGHEZAN, AMADEUS DOBRESCU CHEMICAL COMPOSITION AND ANTIMICROBIAL ACTIVITY OF ESSENTIAL OIL OF ROMANIAN ORIGANUM VULGARE The aim of this study was to determine the chemical characterization and antimicrobial properties of the essential oil of Romanian Origanum vulgare. The oil was isolated by hydro distillation. The chemical composition was characterized by Gas chromatography-Mass spectroscopy. Antibacterial activity was evaluated by disk diffusion method and determination of the minimum inhibitory concentration (MIC).Thirty-two volatile constituents were identified in the oil studied and the major compounds were thymol (35.51%), g-terpinen (19.19%), durenol (17.99%), durene (11.40) and carvacrol (2.69%). It showed a bactericidal activity towards all tested reference strains: Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes and Candida albicans.