Table 1.

Antibacterial activity against Gram-positive bacteria.

Bacterial Strain	Dose	Details about the Source of the Oil and Tested Concentration	Reference
Staphylococcus aureus	MLC (minimal lethal concentration) = 320 μg/mL CZD (clear zone diameter) = 35 mm	Cold-pressed OEO was purchased from a local market in Mecca, Saudi Arabia (100 µL) Using TLC they have identified 91% lipids, followed by 0.7% glycolipids and 0.5% phospholipids. The research team also identified high amounts of linoleic and oleic acids. Both fatty acids accounted for 83% of the total fatty acid methyl esters. HPLC assay confirmed high levels of α-, β-, γ- and δ-tocopherols in OEO 180.4, 60.4, 650 and 117.6 mg/100 g oil, respectively. Besides, amounts of α-, γ- and δ-tocotrienols were 521, 58.9, and 430 mg/100 g oil, respectively. -MLC and CZD values were determined by agar well diffusion method Standards for comparison in antibacterial tests were Augmentin (30 µg), Chloramphenicol (30 µg), with CZD values 40 mm and 25 mm, respectively.	[34]
	MIC(minimum inhibitory concentration) = 0.596 mg/mL MBC (minimum bactericidal concentration) = 0.596 mg/mL MRSA MIC = 1.193 mg/mL MBC = 1.193 mg/mL	OEO was obtained from Ferquima Industry and Commerce of Essential Oils (São Paulo, Brazil) The main components consisted of: carvacrol (71%), thymol(3%), gamma-terpinene(4.5%), para-cymene(3.5%), beta-caryophyllene(4%) Tested concentrations of OEO ranged from 0.075 to 9.540 mg/mL MIC and MBC were determined by the broth dilution method	[35]
	CZD = 41.025 mm (ATCC 43300) CZD = 32.50 mm (ATCC 29213)	Origanum vulgare ssp. hirtum was collected from Kürtün, Turkey GC-MS/FID attested the presence of: carvacrol(65.080 ± 0.003%), thymol(10.490 ± 0.003%), γ-terpinene(7.340 ± 0.003%) Antibacterial activity of the essential oil was evaluated by disc diffusion method	[36]
	MIC = from 0.08 to 0.16 mg/mL A normal lessening in bacterial luminescence of 2.9 log10 was accomplished in 40 min at 5 mg/mL of OEO	OEO was acquired from Bulk Apothecary (Aurora, CO, USA) By the help of GS-MS analysis the main phytochemicals have been identified: carvacrol (72.25%) thymol (6.62%), p-cymene (5.21%), γ-terpinene (4.12%), α-pinene (1.21%) For determination of MIC, broth microdilution assay was performed. For the antibiofilm activity of the EO, Alamar Blue assay was employed Real-time monitoring of disease within the mouse burn wounds in vivo was performed through bioluminescence imaging.	[37]
	MIC = 0.28 mg/mL MBC = 0.67 mg/ml	Origanum vulgare L. was harvested from Alexandria, Behera and Matrouh in northern Egypt. GS-MS assay detected OEO’s main constitutes: pulegone 77.45%, menthone 4.86%, cis-isopulegone 2.22%, piperitenone 2.13%. The antibacterial activity of the essential oil was estimated using the microdilution method	[38]
Staphylococcus epidermidis	CZD = 52.00 mm	Source of the Origanum vulgare L. and chemical constituents were mentioned above in reference [35].	[36]
	MIC = 0.67 mg/mL MBC = 1.34 mg/mL	OEO was provided from the Department of Food Science and Technology, Nebraska University, Lincoln, NE, USA Chemical components of OEO were analyzed using GC-MS and showed thymol 99.44%, p-cymene, cineole and γ-terpinene as major constituents. OEO was screened for the antibacterial activities using broth microdilution method.	[39]
Streptococcus pyogenes Erythromycin-resistant Group A Streptococcus pyogenes	MIC = 256 to 512 μg/mL	OEO was purchased from Sigma–Aldrich (St. Louis, MO, USA) Phytochemical constituents are not mentioned MIC was determined by agar dilution and microdilution methods.	[40]
	MIC = 0.5 mg/mL MBC = 0.5 mg/mL MBEC(minimal biofilm eradication concentration) = 0.5 mg/mL MBIC(minimum biofilm inhibitory concentration) = 0.5 mg/mL OEO at the concentration of 0.5 mg/mL, caused 99.9% elimination of the initial bacterial inoculum after 0.08 h (5 min) of exposure	Oregano (Origanum vulgare L.) was collected from Truro, NS, Canada. According to the GC-FID(gas chromatography-flame ionization detector), carvacrol (91.6%) was the main phytoconstituent in OEO The effects of the OEO on the inhibition of bacterial growth was determined using a micro- broth dilution method. The bactericidal activity of the OEO was studied using modified time-to-kill assays.	[41]
Streptococcus pneumoniae	MIC = 2.5–10 μL/mL The treated biofilm with EO showed a significant reduction in the number of adherent bacteria and also the size of aggregates, which were reduced to small clusters or even single cells. OEO was able to significantly reduce biofilm formation as well as eradicate preestablished biofilms (p < 0.05).	Origanum vulgare L. was obtained from Tehran, Iran. GS-MS (gas chromatography-mass spectrometry) analysis showed for OEO, the main compounds were: pulegone (44.31%), 1,8-cineole (17.47%), borneol (6.20%). MIC was determined by broth micro- dilution method. The anti-biofilm activity of OEO (tested concentrations were MIC/2, MIC/4, and MIC/8) was determined by Microtiter-Plate Test and SEM (scanning electron microscope).	[42]
Bacillus cereus	MIC = 1.56 µL/mL MBC = 3.125 µL/mL	Origanum vulgare L. was collected from Latakia, Syria. The essential oil was analyzed by GC-MS and the major components were: terpinen-4-ol (24.90%), gamma-terpinene (10.57%), o-cymene (8.90%) Tested concentrations ranged from 200 to 0.0487 µL/mL	[43]
	MIC = 0.11 mg/mL MBC = 0.21 mg/mL	Origanum vulgare L. was harvested from Alexandria, Behera and Matrouh in northern Egypt. GS-MS assay detected OEO’s main constitutes: pulegone (77.45%), menthone (4.86%), cis-isopulegone (2.22%), piperitenone (2.13%) The antibacterial activity of the essential oil was estimated using the microdilution method.	[38]
Enterococcus faecalis	MIC = 8 mg/mL Inhibition zone = 13 ± 1 mm	OEO was obtained from the Magnolia Company (Tehran, Iran) The chemical composition of OEO was determined by GC–MS and the main constituents were: terpinene-4-ol (21.43%), g-Terpinene (12.32%), carvacrol (11.67%) thymol (9.45%) MIC value was determined by the broth microdilution method. Disk diffusion was employed for estimating the antibacterial activity of 20 µL of the Eos.	[44]
	CZD = 24.25 mm	Source of the Origanum vulgare L. and chemical constituents were mentioned above in reference [35].	[36]
Listeria monocytogenes	MIC = 0.6 µL/mL- L. monocytogenes ATCC 7644, LM17 MIC = 1.2 µL/mL- L. monocytogenes LM 4	The OEO used in this study was purchased from an Italian company: Zuccari SRL (Trento) GC-MS attested the presence of: carvacrol (68,1%), o-Cymene (5,9%), -thymol (3,7%) MIC values were obtained according to the microdilution method.	[45]
	MLC = 320 μg/mL CZD = 15 mm	Source of the Origanum vulgare L. and chemical constituents were mentioned above in reference [34].	[34]
	MIC = 0.40 mg/mL/ MBC = 0.83 mg/mL	Source of the Origanum vulgare L. and chemical constituents were mentioned above in reference [38].	[38]
Propionibacterium acnes	MIC = 0.34 mg/mL MBC = 0.67 mg/mL	Source of the Origanum vulgare L. and chemical constituents were mentioned above in reference [39].	[39]