Antimicrobial and Antifungal Effects of Essential Oils from Origanum vulgare, Lavandula officinalis, and Syzygium aromaticum on Bacterial Strains through Gaseous Contact

Background: Hospital-acquired infections, also known as nosocomial infections, affect thousands of patients worldwide. In Algeria, these infections raise significant concerns and give rise to numerous questions due to hygiene deficits and non-compliance with preventive measures. Objective: The main objective of this study was to investigate the antibacterial and antifungal properties of Origanum vulgare, Lavandula officinalis, and Syzygium aromaticum, as well as their combinations, to discover new antibacterial and antifungal agents to combat nosocomial infections related to hospital and medical care environments. Materials and Methods: Essential oils were obtained by a Clevenger-type apparatus and analyzed using GC and GC/MS. The antimicrobial and antifungal activity was tested against several bacteria responsible for nosocomial infections in in-vitro tests using the gas contact method in sealed containers. Results: The essential oil extracted from S. aromaticum buds was primarily composed of eugenol (59.4%), E-β-caryophyllene (16.5%), and eugenyl acetate (10.5%). The analysis of the chemical composition of L. officinalis essential oil identified 1,8-cineole (22.8%), β-pinene (12.4%), and linalool (8.5%) as the main compounds. As for O. vulgare essential oil, its major components were carvacrol (72.6%) and thymol (10.5%). The results revealed that the essential oils of L. officinalis, O. vulgare and S. aromaticum, as well as their combinations, used at a concentration of 1/10, had a remarkable effect on the E. coli, P. aeruginosa and K. pneumoniae strains. In contrast, they had a limited effect on the Gram-positive strain, S. aureus. The antifungal effectiveness of the essential oil of O. vulgare, as well as the combination of O. vulgare and S. aromaticum, has been remarkable against the C. albicans species, leading to a complete inhibition of yeast growth. Conclusion: Our results indicate that our essential oils have a broad spectrum of antimicrobial activity, which makes them particularly useful as disinfectants in health facilities and could be used as a valuable medicine to control nosocomial infections and avoid infections acquired during a stay in a health facility such as respiratory tract infections and urinary tract infections.