The protocol of the Clinical and Laboratory Standards Institute (CLSI) [67,68] was followed with some modifications. The bacterial suspensions were diluted to a McFarland standard of 0.5 (0.5 McFarland standard is prepared by mixing 0.05 mL of 1.175% barium chloride dihydrate (BaCl2·2H2O), with 9.95 mL of 1% sulfuric acid (H2SO4), and adjusted to about 104–105 bacteria/mL before use. A 0.1 mL portion from this bacterial dilution was spread on Mueller–Hinten (MH) agar (MHA, Sigma-Aldrich, Darmstadt, Germany). Subsequently, sterile paper discs (Macherey-Nagel, Düren, Germany, LOT: 141112) 6 mm in diameter were placed within 15 min onto the inoculated agar surface containing 10 µL of the essential oil or 10 µL of sterile water as control. Petri dishes were incubated at 37 °C for 24 ± 1 h. After incubation, the inhibition zones were measured as the complete inhibition in mm, as a diameter including the disc. The inhibition zones were measured in triplicate with a vernier caliper. The distance from the colonies closest to the disc to the center of the disc was doubled to obtain a diameter.