Chemical composition of Thymus vulgaris extracts and antibacterial activity against pathogenic multidrug resistance bacteria

Abstract The antibiotic-resistance represent a global concern due to capability of Bacteria to continuously evolution unique mechanisms of resistance against different antimicrobial classes, thus, there is un argent need to discover new antibiotics with novel chemical structure and unique mechanism of action. Therefore, the present study aimed to investigate the antimicrobial activity of Thymus vulgaris leaves extracts against several bacterial pathogens including Multiple drug resistance (MDR) strains. T. vulgaris leaves extracts showed a potent antibacterial activity against tested pathogens including the Methicillin-resistant S. aureus (MRSA) and Multiple drug resistance A. baumannii with obvious superiority for ethyl acetate extract. The most susceptible pathogen was S. typhimurium by 30 mm and 40 mm zone of inhibition for hexane and ethyl acetate extracts respectively followed by B. subtilis whereas E. faecalis and Methicillin-resistant S. aureus were the least affected with inhibition zone of 18 mm and 17 mm respectively for ethyl acetate extract. The MIC value for ethyl acetate extract ranged between μ g / mL , Multiple drug resistance A. baumannii showed an interested susceptibility to ethyl acetate extract by MIC of 156 312 μg/mL. Phenol 2-methyl-5-(1-methylethyl) commonly known as carvacrol was the major compound (9.5%) in the leaves extracts of T. vulgaris, carvacrol reported to possesses potent antibacterial properties against pathogenic bacteria, thus the antibacterial activity of ethyl acetate and hexane may attributed to this compound alone or in synergy with other molecules of the extract including benzene 1-methyl-4-(1-methylethyl) ∼(5%), Bicyclo[5.2.0]nonane, 2-methylene-4,8,8-trimethyl-4-vinylv (2.5%) and borneol (2.2%). Our data obtained in this work showed the important of natural products as source for compounds with biological activities. Thus Further chemical tests are needed to purify the compound to which the antibacterial activity is attributed.