ANTIMICROBIAL ACTIVITY OF SINGLE AND BLENDED ESSENTIAL OILS AGAINST PROBIOTICS AND SALMONELLA ISOLATES COLLECTED FROM FARMED POULTRY AND SWINE

Antimicrobial resistance (AMR) represents a serious threat to human health, as well as to food-producing animals and the environment. AMR is a growing phenomenon, while antibiotic efficacy against human and zoonotic infections is decreasing. Salmonellosis is the 2nd most common zoonosis in Europe, and recent studies highlight multidrug resistance (MDR) of numerous Salmonella strains to the most commonly used antimicrobial agents. EOs could meet some of the strategic objectives outlined in the WHO's Global Action Plan on AMR. Salmonella is the most frequently isolated bacterial agent in food-borne infections. Food-producing animals are the main reservoirs of infection, with animal-derived foods (meat, eggs and milk) sources of transmission. The aim of the study was to evaluate antibacterial efficacy of single EOs (Lavandula intermedia and Origanum vulgare) and of GR-OLI (25% commercial solution of an unknown mixture of Eucalyptus globulus, Satureja montana, Citrus aurantium var. dulcis, Thymus vulgaris, Melaleuca alternifolia, Citrus limon, Lavanda hybrida, Melaleuca cajeputi, Thymus capitatus) against Salmonella (29 strains) isolated from swine and poultry farms and against beneficial microorganisms used as probiotics, including Saccharomyces cerevisiae, S. boulardii, Enterococcus faecium and Bifidobacterium thermoacidophilum (6 strains). EO efficacy was evaluated through MIC analysis according to EUCAST guidelines.