Potential Applications of Essential Oils for Environmental Sanitization and Antimicrobial Treatment of Intensive Livestock Infections

Abstract

The extensive use of antibiotics has contributed to the current antibiotic resistance crisis. Livestock infections of Salmonella spp, Clostridium spp. and E. coli antimicrobial-resistant bacteria represent a public threat to human and animal health. To reduce the incidence of these zoonoses, essential oils (EOs) could be effective antibiotic alternatives. This study aims at identifying EOs safe for use, effective both in complementary therapy and in the environmental sanitization of intensive farming. Natural products were chemo-characterized by gas chromatography. Three S. Typhimurium, three C. perfringens and four E. coli strains isolated from poultry and swine farms were used to assess the antimicrobial properties of nine EOs and a modified GR-OLI (mGR-OLI). The toxicity of the most effective ones (Cinnamomum zeylanicum, Cz; Origanum vulgare, Ov) was also evaluated on porcine spermatozoa and Galleria mellonella larvae. Cz, Ov and mGR-OLI showed the strongest antimicrobial activity; their volatile components were also able to significantly inhibit the growth of tested strains. In vitro, Ov toxicity was slightly lower than Cz, while it showed no toxicity on G. mellonella larvae. In conclusion, the study confirms the importance of evaluating natural products to consolidate the idea of safe EO applications in reducing and preventing intensive livestock infections.

Rapid Classification and Recognition Method of the Species and Chemotypes of Essential Oils by ATR-FTIR Spectroscopy Coupled with Chemometrics

“…As can be seen in Table S1 , MA and MP EOs exhibited similar compositions. Both the EOs were rich in the alcoholic monoterpene menthol, the ketonic monoterpenes menthone and isomenthone, and the ester methyl acetate, accordingly to the literature [ 19 , 20 , 21 , 22 ]. On the contrary, the composition of MS-EOs extremely differed from the other two species.…”

A New Potential Resource in the Fight against Candida auris: the Cinnamomum zeylanicum Essential Oil in Synergy with Antifungal Drug

“…To investigate the toxicity of CZ-EO, in vivo experiments conducted in the model of Galleria mellonella larvae were done. This model was chosen because it was already used to evaluate the toxicity of essential oils in general and of CZ-EO in particular ( 20 , 24 ). The toxicity of the EO was evaluated by testing serial dilutions ranging from 32% vol/vol to 0.5% vol/vol on G. mellonella larvae.…”

“…Nowadays, essential oils (EOs), alone or in combination with conventional drugs, are used to fight human pathogens, including multidrug-resistant ones ( 16 to 19 ). EOs are mixtures of natural substances obtained from the distillation or pressing of aromatic plants with a known antimicrobial activity ( 20 ). There are several essential oils with known antifungal activity ( 21 ).…”

Evaluation of the composition and antimicrobial activities of essential oils from four species of Lamiaceae Martinov native to Iran

“…Essential oils obtained from Lamiaceae have gained considerable interest since their rich content in biological active molecules especially volatile molecules, such as monoterpenes, sesquiterpenes, and coumarins in some cases 5 , 6 . The antifungal and antimicrobial effect of several essential oils from this family, like thyme, peppermint, lavender, rosemary, peppermint, savory and marjoram, has been previous demonstrated 7 , 8 . The essential oil obtained from Thymus daenensis Čelak., endemic in NE Iraq and Iran, contains thymol, carvacrol, and p-cymene in high amount 9 – 15 .…”