Paper Title
Antimicrobial Activity of Thymus Vulgaris Extract on Strains of Pathogenic Bacteria

Abstract
This study was design to evaluate the antibacterial activity of Thymus Vulgaris extract against different strains of bacteria (Salmonella enterica, Escherichia coli, Staphylococcus aureus, and Bacillus cereus). The growth of bacteria was determined by monitoring the increase around the thyme extract. Results revealed that Thymus Vulgaris extract has a tremendous antimicrobial effect on these bacterial strains. At the two highest concentrations (5.536 and 1.384 μg/ml), Thymus vulgaris extract inhibited the growth of bacteria (Salmonella enterica, Escherichia coli, Staphylococcus aureus, and Bacillus cereus); whereas at concentrations (0.346 and 0.0865 μg/ml), Thymus vulgaris extract showed slight antibacterial activities only against Bacillus cereus and Staphylococcus aureus. In addition, the results of the diameters of the inhibition zones reveal that this extract develops important zones of inhibition in Staphylococcus and Bacillus cereus, whereas Escherichia coli and Salmonella seem sensitive towards Thymus Vulgaris extract with the diameters of the inhibition zones from 1.6 to 3 cm for Staphylococcus and from1.5 to 2.2 cm for Bacillus cereus, and 1.6 and 1.7 cm for Escherichia coli and Salmonella. These findings highlight that the ethanoic extract of Thymus Vulgaris holds antimicrobial properties and it's more effective on gram positive bacteria (Staphylococcus, and Bacillus cereus) than on gram negative bacteria (Salmonella, Escherichia coli). Keywords - Thymus vulgaris, Salmonella enterica, Escherichia coli, Staphylococcus aureus, Bacillus cereus.