Antimicrobial effects of Rosmarinus Officinalis; in-vitro study

Introduction: The plant Rosmarinus officinalis (RO) is a member of the Lamiaceae family and is more commonly known as rosemary. This study's primary objective is to compare the antimicrobial effect of RO extract at different concentrations on various microorganisms. Material and Methods: Strains of S. aureus ATCC 29213, K. pneumoniae ATCC 13883, and E. coli ATCC 25922 obtained from the national reference center were inoculated into liquid Müller Hinton broth (Oxoid, UK) and incubated at 37 oC’ for 24 hours. To assess the antimicrobial efficacy of the RO extract, dilutions of 0.0625%, 0.125%, 0.25%, 0.5%, 1%, 2%, 3%, and 4% were prepared. Results: The MIC value for RO extract was 2% for S. aureus ATCC 29213 and K. pneumoniae ATCC 13883 and 3% for E. coli ATCC 25283. A statistically significant difference was found between the three groups, including 0.0625% and 2% of RO, in terms of the growth rates of microorganisms (p<0.001). There was no statistically significant difference between the concentrations of 3% and 4% (p=1.00). Discussion: The antimicrobial effect potential of RO has been demonstrated in the literature and in-vito in this study. In addition, we believe it can be used as a prophylactic or as an alternative to antimicrobial agents in the topical or systemic treatment of SSIs due to its various effects, topical, oral, and systemic use, and low cost. Thus, it is anticipated that the costs of treatment will be reduced. To determine the efficacious dose and implement it in clinical practice, experimental and clinical studies are necessary.