Antimicrobial activity of Zataria multiflora boiss. essential oil on Staphylococcus aureus isolated from raw milk

Enterotoxin-producing strains of Staphylococcus aureus can cause food poisoning through the consumption of contaminated dairy products. Essential oil (EO) of Zataria multiflora Bioss. contains components with antibacterial and antifungal properties. The present study was conducted to determine the minimum inhibitory concentration (MIC) of Z. multiflora Boiss. EO on S. aureus isolated from raw milk. Extraction and gas isolation of the EO was provided and analyzed by Chromatography/mass spectrometry. A total of 84 samples of raw milk from a dairy farm in Semnan were analyzed for the presence of S. aureus. Fourteen S. aureus strains were isolated from raw milk. The chemical composition of hydrodistilled EO of Z. multiflora Boiss was analyzed by Chromatography/mass spectrometry. A total of 25 compounds representing 98.59% of the oil were identified: carvacrol (50.53%), thymol (14.7%), p-cymene (7.9%), Carvacryl acetate (3.85%) and Trans-caryophyllene (3.4%). The MIC of Z. multiflora Boiss. Using broth microdilution method, MIC of EO on all of the S. aureus isolates was estimated at 0.0001-0.004. Based on results, the EO ofZ. multiflora Boiss possesses antibacterial activity on S. aureus isolated from raw milk.