Avaliação da atividade antimicrobiana do óleo essencial de Mentha x piperita (Laminaceae) contra bactérias de importância médica e veterinária

Abstract

The indiscriminate and irresponsible use of antibiotics today represents a major challenge for both human and veterinary medicine. The emergence of bacterial strains resistant to conventional therapies makes it necessary to search for new therapeutic options for the treatment of infectious diseases that pose a risk to One Health; among these, phytotherapy stands out. Currently, several plants are being studied for their antimicrobial action. Peppermint essential oil (Mentha-piperita), a plant belonging to the Lamiaceae family, contains compounds such as menthol and menthone, which stand out because they have several therapeutic applications, including anti-inflammatory, antimicrobial, antifungal, antioxidant, and analgesic properties. In this study, peppermint essential oil was used against strains of Pseudomonas aeruginosa, Shigella flexneri, Streptococcus uberis, Streptococcus agalactiae, Streptococcus pyogenes, Enterococcus faecalis, and Bacillus cereus, pathogens of great importance to human and veterinary medicine. The work was carried out between May 2025 and April 2026 at the Federal University of the Southern Frontier (UFFS), Realeza Campus, PR, Brazil. After standardization of the inoculum, assays were performed in triplicate to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC), and the results were analyzed using descriptive statistical analysis. The MIC and MBC values obtained ranged from 0.04882% to 0.78125% against all evaluated pathogen strains, revealing, through the MBC/MIC ratio, a predominantly bactericidal profile. E. faecalis and B. cereus strains showed lower bactericidal concentrations (MBC 0.78125%); MIC analysis revealed that bacteria of the genus Streptococcus showed greater sensitivity to inhibitory screening. The results obtained in this study demonstrated that the essential oil exhibited antibacterial activity against the evaluated bacterial strains, evidenced by the observed MIC and MBC values. The variation in sensitivity among microorganisms indicates that the efficacy of the essential oil depends on the bacterial species analyzed. Thus, the essential oil shows itself as a potential candidate for the development of products with antimicrobial activity for medicinal purposes.