A comparative study of the antimicrobial activity of oregano, rosemary and thyme essential oils against Salmonella spp

The emergence of Salmonella resistance to therapeutic agents against human infections is attributed to their excessive use in the treatment of food-producing animals. The spreading of resistance necessitates vigorous research on alternative therapeutic schemes in order to replace commonly used antimicrobials. Thus, the aim of the present study was to investigate the inhibitory activity of three commercially available essential oils (EOs) against fifty-nine Salmonella strains belonging to fourteen serovars isolated from pig carcasses at slaughter. Their antimicrobial activity was compared with that of twenty-four commonly used antimicrobials previously tested against the same strains. The three chosen EOs were oregano, rosemary and thyme. Oregano and thyme EOs showed high antimicrobial activity, compared to that of rosemary and a better antimicrobial effect compared to that of commercial antimicrobials. The results showed that oregano and thyme have the potential of an effective alternative treatment against Salmonella spp., especially those strains resistant to synthetic antimicrobials. Thus, some EOs could be a safer alternative treatment against certain infections of food-producing animals or, perhaps, growth promoters, used for effective prevention. *Correspondence to: Grammato Evangelopoulou, Department of Nursing, Faculty of Human Movement and Quality of Life Sciences, Laboratory of Integrated Healthcare, University of Peloponnese, Sparta, Greece, Tel: 30-694584-7840, E-mail: matinavet@hotmail.com