Use of Essential Oils in Veterinary Medicine to Combat Bacterial and Fungal Infections

Abstract

Essential oils (EOs) are secondary metabolites of plants employed in folk medicine for a long time thanks to their multiple properties. In the last years, their use has been introduced in veterinary medicine, too. The study of the antibacterial properties of EOs is of increasing interest, because therapies with alternative drugs are welcome to combat infections caused by antibiotic-resistant strains. Other issues could be resolved by EOs employment, such as the presence of antibiotic residues in food of animal origin and in environment. Although the in vitro antimicrobial activity of EOs has been frequently demonstrated in studies carried out on bacterial and fungal strains of different origins, there is a lack of information about their effectiveness in treating infections in animals. The scientific literature reports some studies about in vitro EOs’ activity against animal clinical bacterial and fungal isolates, but in vivo studies are very scanty. The use of EOs in therapy of companion and farm animals should follow careful studies on the toxicity of these natural products in relation to animal species and route of administration. Moreover, considering the different behavior of EOs in relation to both species and strain pathogen, before starting a therapy, an aromatogram should be executed to choose the oil with the best antimicrobial activity.

Anti-Staphylococcal Activity of Cinnamomum zeylanicum Essential Oil against Planktonic and Biofilm Cells Isolated from Canine Otological Infections

“…This study shows that CZEO was composed mostly by phenylpropanoids, specifically ( E )-cinnamaldehyde (77.42%), eugenol (8.17%), and ( E )-cinnamyl acetate (4.50%). These results agreed with the major components reported for CZEO chemical composition [ 11 , 12 ]. The potential use of ( E )-cinnamaldehyde and eugenol, regardless their origin, has been quite explored due to significant broad-spectrum activity against pathogenic bacteria [ 13 , 14 ].…”

“…Studies relating natural plant products as new alternatives to combat MDR bacteria have gained researchers attention to develop creams and gels for topical applications [ 31 , 32 ]. EOs, widely commercialized, have become a viable alternative for the development of new treatments against skin infections in veterinary medicine, including pyoderma, media- and external-otitis [ 11 ].…”

“…Essential oils (EO), their main constituents, and most recently their association with antibiotics have been widely studied as promising therapeutic alternatives against different species of the Staphylococcus genus [9,10]. Studies exploring veterinarian applications of EOs as antimicrobials to treat microorganisms that cause skin infections in dogs are incipient, but promising [11,12]. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of Cinnamomum zeylanicum EO (CZOE) against Staphylococcus sp.…”

Overcoming Multidrug Resistance in Salmonella spp. Isolates Obtained From the Swine Food Chain by Using Essential Oils: An in vitro Study

“…As mentioned above, the possibility of combining antibiotics with EOs can be an alternative to overcome AMR in bacteria ( Solarte et al, 2017 ). In veterinary clinical practice, data concerning EO treatments in vitro and in vivo do not draw a complete picture as in human medicine ( Ebani and Mancianti, 2020 ). Nevertheless, the positive outcomes of EO treatments have been correlated with both their direct antimicrobial effects and their aspecific antioxidant and anti-inflammatory effects ( Miguel et al, 2020 ), along with the immunomodulatory activity ( Valdivieso-Ugarte et al, 2019 ).…”

Medicinal Properties and In Vitro Biological Activities of Selected Helichrysum Species from South Africa: A Review

“…Essential oils (EOs) are the condensed or concentrated hydrophobic liquids that contain volatile chemical compounds derived from plants. The variety of compounds in EOs depends on such factors as the plant species, plant part used (leaves, fruits, roots), harvest period, environmental conditions (land fertility, humidity, temperature) and the extraction technique employed [ 68 ].…”