Antibacterial activity of Cinnamomum verum and Thymus vulgaris essential oils on multidrug-resistant zoonotic bacteria isolated from dogs in southern Benin.

Abstract

Antibiotic resistance is a major public health problem. The search for new therapeutic alternatives is becoming urgent. Essential oils are a promising alternative. This study aimed to evaluate the antibacterial activities of essential oils from selected plants on multidrug-resistant zoonotic strains isolated from dogs. Essential oils from dried Thymus vulgaris leaves, Cinnamomum verum bark and Cuminum cyminum seeds were extracted and tested on five multidrug-resistant Escherichia coli and four Staphylococcus aureus isolated from dogs in southern Benin. The study showed that T. vulgaris essential oil was bacteriostatic, with an MIC equal to 2.5 µl ml^-1 and a minimum bactericidal concentration (MBC) of 17 µl ml^-1 for E. coli strains and 11.25 µl ml^-1 for S. aureus strains. Regarding C. verum essential oil, its bacteriostatic power was characterized by an MIC of 1.25 µl ml^-1 for the isolates tested and an average MBC of 11.50 µl ml^-1 for E. coli and 12.19 µl ml^-1 for S. aureus. On the other hand, C. cyminum essential oil was ineffective on the strains investigated. Additionally, T. vulgaris essential oil contained predominantly thymol (36.57%), p-cymene (30.51%) and carvacrol (7.62%), whilst C. verum essential oil contained cinnamaldehyde (88.76%). This study reveals the antibacterial activity of T. vulgaris dry leaf and C. verum bark essential oils on multi-resistant E. coli and S. aureus isolated from dogs. These two essential oils may be alternative candidates for combating antibiotic-resistant E. coli and S. aureus infections.