Antibacterial activity of Thymus vulgaris (thyme) essential oil against strains of Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus saprophyticus isolated from meat product

Meat products represent an important component of the human diet and are a good source of nutrients. Food-borne microorganisms are the main pathogens that cause human diseases as a result of food consumption, especially products of animal origin. The objective of the present research was to verify the antibacterial activity of the essential oil of Thymus vulgaris against strains of Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus saprophyticus isolated from meat products. For this, the analyses of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were performed in microdilution plates. The association of the product with antimicrobials was also studied using disk diffusion. And the anti-adherent activity, which was determined in the presence of sucrose, in glass tubes. Thyme oil showed a strong inhibitory activity against K. pneumoniae, P. aeruginosa and S. saprophyticus, with the MIC values ranging from 64 to 512 μg/mL, and bactericidal effect for most strains, with MBC values ranging from 256 to 1,024 μg/mL. T. vulgaris oil exhibited varied interactions in association with the antimicrobials, with synergistic (41.67%), indifferent (50%) and antagonistic (8.33%) effects. Regarding the anti-adherent activity, the test product was effective in inhibiting the adherence of all bacterial strains under study. Therefore, thyme oil presents itself as an antibacterial and anti-adherent agent against K. pneumoniae, P. aeruginosa and S. saprophyticus, being a natural product that can represent an interesting alternative in the efforts to combat foodborne diseases.