The effects of the hydroalcoholic extract of Thymbra spicata on some gram positive and gram negative pathogenic bacteria

Treatment of bacterial diseases by synthetic antibiotics leads to problems such as side effects in human and antibiotic resistance in microorganisms. Recently, plants have been given more attention in curing bacterial diseases. Since the use of Thymbra spicata is common in Iranian ancient medicine, this study tried to investigate the antibacterial effects of the extract of Thymbra speculate on some gram positive and gram negative pathogenic bacteria. The mentioned plant was collected from Zagros mountains, Ilam province, Iran. After naming and identification, the plant extract was provided by the maceration method. The bacteria were affected by different concentrations of the extract using the disc diffusion method. Diagnostic antibiotics were used as positive control and DMSO as negative control. MIC and MBC were also determined. The highest effect of the extract was found in gram positive bacteria. The maximum zones of inhibition were observed in 76 mg/ml concentration of the extract, and S. aureus and S. epidermidis were more sensitive than other bacteria (P˂0.05). The lowest MIC was pertaining to S. aureus (1885) with 2.5 mg/ml and S. epidermidis (2405) with 5mg/ml of extract. E. coli and K. penemonia with 15 mm zone of inhibition were the most sensitive gram negative bacteria to the extract. The hydroalcoholic extract of T. spicata had a considerable antibacterial effect. Statistic assessment of the inhibition zones showed that the extract was more effective on gram positive bacteria