Phytochemical investigation and inhibitory effect of Thymus eriocalyx (Ronniger) Jalas essential oil on the growth of bacteria (Enterococcus faecalis and Salmonella typhimurium)

Nowadays, due to the complications caused by the use of chemical drugs and the increase of antibiotic-resistant microbial strains, studies have been conducted to find antibacterial drugs from plant compounds. In this research, the aerial parts of Thymus eriocalyx were collected from the heights of Kermanshah in June 1400 (810 meters) in the flowering stage. The essential oil was extracted by distillation with water using a Cloninger machine. The antimicrobial activity of the essential oil of this plant in successive concentrations of 250, 125, 62.5, 31.25, 15.62, 7.81, 3.9, 1.95, 0.97 and 0.48 mg/ml against two bacterial species Enterococcus faecalis and Salmonella typhimurium by determining the minimum inhibitory concentration (MIC) in broth medium, minimum lethal concentration (MBC) in agar medium and disk diffusion were investigated. Ampicillin with a concentration of 10 mg/ml, ciprofloxacin 5 mg/ml, erythromycin 15 mg/ml and cefixime 5 mg/ml were used as positive controls. Mass gas chromatography method showed that this type of thyme has 42 effective substances. The most phenolic composition of the pasture ovia is carvacrol (66.96%). MBC for Enterococcus faecalis and Salmonella typhimurium bacteria was 15.67 and 62.5 mg/ml, respectively. 250 and 125 mg/mol discs were better than selected antibiotics in inhibiting both bacteria. The essential oil of pasture thyme plant contains antiseptic substances with antibacterial effects. The effect of essential oil in stopping the growth of Gram-positive bacteria was greater than that of Gram-negative bacteria. Considering that the essential oil of the plant had significant antibacterial effects compared to antibiotics in laboratory conditions, it is suggested to carry out more experiments to evaluate its effect in animal models.