Effect of the essential oil, infusion and ethanol extract of Thymus vulgaris L, on the growth in vitro of group a β-hemolytic Streptococcus pyogenes

Abstract Biological activity of the distilled essential oil, ethanol extract, and infusion of thyme (Thymus vulgaris L.) was evaluated on the growth of group A ß-hemolytic Streptococcus pyogenes, the primary cause of faryngoamygdalitis. Sensitivity tests and measurements the zones of inhibition in vitro was performed. The distilled essential oil showed the greatest effect (inhibition halo of 3.2 cm), superior even to penicillin (2.4 cm). The ethanol extract had less effect, and the infusion showed no effect. The essential oil and the ethanol extract were analyzed by gas chromatography to determine the concentration and purity of their principal components and to compare these to the commercially available pure essential oil of thyme. These analyses allowed us to establish the presence of thymol and to a lesser extent carvacrol, both of which are known to inhibit bacterial growth.