Antibacterial Effects of Oregano Essential Oil (OEO) and Its Potential Applications

Main Article Content

R. Cabrera-Contreras
R. Morelos-Ramírez
J. P. Quiróz-Ríos
D. Muñoz-Quiróz


Essential oils (EOs) are commonly used in food industry, due that they possess antioxidative and antimicrobial properties. There are few essential oils that have been used in medicine, due to its potent antibacterial activity against intrahospital pathogens. OEO has experimentally shown potent antibacterial effect on nosocomial Gram-positive bacteria, therefore it can be very useful in hospital environments, where there are many bacterial pathogens, which are the etiological agents of nosocomial infections and most of them are resistant to several antibiotics.

Objective: The aim of this study was to determine antimicrobial effect of OEO on most frequent bacterial intrahospital pathogens: MRSA, MRSE comparatively to selected ATCC bacterial reference strains.

Methods: This experimental study investigates the antibacterial action of oregano (Origanum vulgare) essential oil (OvEO) on two human pathogens: Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE) Here, we used OEO against one of the most prominent antibiotic-resistant bacterial strains: methicillin-resistant SA (MRSAmecA+ = Meticillin Resistant SA and mecA- = Meticillin Resistance SA ), methicillin-resistant SE (MRSEmecA+ = Meticillin Resistance Staphylococcus epidermidis mecA+) and reference strains: S. aureus ATCC 700699, S. epidermidis ATCC 359845 and E. coli ATCC 25922. Bactericidal effects of the OEO on these bacteria were mainly evaluated using undiluted and four serial dilutions in coconut oil (CCO) l: 1:10, 1:100, 1:200, 1:400.

Results: OEO, undiluted and 4 serial dilutions showed potent antibacterial activity against all strains tested. In conclusion, this OEO could be used as an alternative in medicine. The ability of OEO to inhibit and kill clinical Multi-Drug-Resistant (MDR): MRSA and MRSE strains, highlights it´s potential for use in the management of drug-resistant MDR infections in hospitals wards.

Antibacterial effects, essential oil, antibiotics, contaminant bacteria

Article Details

How to Cite
Cabrera-Contreras, R., Morelos-Ramírez, R., Quiróz-Ríos, J. P., & Muñoz-Quiróz, D. (2020). Antibacterial Effects of Oregano Essential Oil (OEO) and Its Potential Applications. Microbiology Research Journal International, 30(4), 19-25.
Short Research Article


Aligiannis N, Kalpoutzakis E, Mitaku S, Chinou IB. Composition and antimicrobial activity of the essential oils of two Origanum species. J. Agric. Food Chem. 2001;49:4168-4170.

Arana-Sanchez A, Estarron-Espinoza M, Obledo- Vazquez EN, Padilla-Camberos E, Silva-Vazquez R, Lugo-Cervantes E. Antimicrobial and antioxidant activities of Mexican oregano essential oils (Lippiagraveolens H. B. K.) with different composition when microencapsulated in beta-cyclodextrin. Lett Appl Microbiol. 2010;50:585-590.

Elgayyar M, Draughon F, Golden DA, Mount JR. Antimicrobial activity of essential oils from plants against selected pathogenic and saprophytic microorganisms. J. Food Protect. 2001; 64(7):1019-1024.

Saeed S, Tariq P. Antibacterial activity of oregano (Origanum vulgare Linn.) against Gram positive bacteria. Pak J Pharm Sci. 2009;22:421-424.

Lambert RJW, Skandamis PN, Coote PJ, Nychas GJE. A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. J Appl Microbiol. 2001;91:453–462.

Nostro A, Blanco AR, Cannatelli MA, Enea V, Flamini G, Morelli I, Sudano Roccaro A, Alonzo V. Susceptibility of methicillin-resistant staphylococci to oregano essential oil, carvacrol and thymol. FEMS Microbiol Lett. 2004;230:191–195.

Nostro A, Marino A, Blanco AR, Cellini L, Di Giulio M, Pizzimenti F, Sudano Roccaro A, Bisignano G: In vitro activity of carvacrol against staphylococcal preformed biofilm by liquid and vapour contact. J Med Microbiol. 2009;58:791-797.

Cabrera CR, Morelos RR, Galicia CAN, Meléndez HE. Antibiotic Resistance and Biofilm Production in Staphylococcus epidermidis Strains, Isolated from a Tertiary Care Hospital in Mexico City. ISRN Microbiology. 2013;2013:5.
[Article ID 918921]
DOI: 101155/2013/ 918921

Styers D. Sheehan DJ, Hogan P, Sham DF. Laboratory-based Surveillance of Current Antimicrobial Resistance Patterns and Trends among S. aureus: 2005 Status in the United States. Ann Clin Microbiol Antimicro. 2006;5(2):1-9.

Warnke PH, Becker ST, Podschun R, Sivananthan S, Springer IN, Russo PA, Wiltfang J, Fickenscher H, Sherry E: The battle against multi-resistant strains: Renaissance of antimicrobial essential oils as a promising force to fight hospital-acquired infections. J Craniomaxillofac Surg. 2009;37:392-397.

Cabrera CR, Ramirez PM, Morelos RR, Meléndez HE. Evaluation of Three Phenotypic Tests vs. Duplex (coa & mecA) PCR For Detection of Methicillin-Resistance Staphylococcus aureus (MRSA) Strains from Patients with Nosocomial Infection (NI) in a Mexican General Hospital. British Res Microbiol J. 2016;12(3):1-7.

Roller S, Ernest N, Buckle J. The antimicrobial activity of high necrodane and other lavender oils on methicillin-sensitive and -resistant Staphylococcus aureus (MSSA and MRSA). J Altern Complement Med. 2009;15:275-279.

Nuryastuti T, van der Mei H, Busscher HJ, Iravati S, Aman AT, Krom BP: Effect of cinnamon oil on icaA expression and biofilm formation by Staphylococcus epidermidis. Appl Environ Microbiol. 2009; 75:6850-6855.

Qiu J, Zhang X, Luo M, Li H, Dong J, Wang J, Leng B, Wang X, Feng H, Ren W, Deng X: Subinhibitory concentrations of perilla oil affect the expression of secreted virulence factor genes in Staphylococcus aureus. PLoS ONE. 2011; 6:e16160.

D’Arrigo M, Ginestra G, Mandalari G, Furneri PM, Bisignano G. Synergism and postantibiotic effect of tobramycin and Melaleuca alternifolia (tea tree) oil against Staphylococcus aureus and Escherichia coli. Phytomedicine. 2010;17:317-322.

Karpanen TJ, Conway BR, Worthington T, Hilton AC, Elliott TS, Lambert PA. Enhanced chlorhexidine skin penetration with eucalyptus oil. BMC Infect Dis. 2010; 10:278.

Karpanen TJ, Worthington T, Hendry ER, Conway BR, Lambert PA. Antimicrobial efficacy of chlorhexidine digluconate alone and in combination with eucalyptus oil, tea tree oil and thymol against planktonic and biofilm cultures of Staphylococcus epidermidis. J Antimicrob Chemother. 2008;62:1031-1036.

Sharafi SM, Rasooli I, Owlia P, Taghizadeh M, Astaneh SD. Protective effects of bioactive phytochemicals from Mentha piperita with multiple health potentials. Pharmacogn Mag. 2010;6:147-153.

Mahboubi M, Ghazian BF: Antistaphylococcal activity of Zataria multiflora essential oil and its synergy with vancomycin. Phytomedicine. 2010;17:548-550.