Monitoring of Antimicrobial Activity of Essential Oils Using Molecular Markers

Abstract

Technological application of essential oils, as natural antimicrobial agents, to reduce the effect of pathogenic
microorganisms, requires new methods of detection. The present work evaluated the parameters of antimicrobial activity
of the essential oils of rosemary (Rosmarinus officinalis) on two pathogenic strains Escherichia coli and Staphylococcus
aureus. The MBC and MIC values were of 2.5, 25 μl ml-1, and values of 1.25 and 5 μl ml-1for the two strains
respectively. In this study, an attempt has been made to evaluate randomly amplified polymorphic DNA (RAPD) analysis
for its potential to establish antimicrobial effect of rosemary essential oil. For the preliminary assessment, this study
compared the effects occurring at molecular levels in E. coli and Staph. aureus exposed to rosemary essential oil at the
MIC concentrations for the two organisms. The qualitative modifications arising in random amplified polymorphic DNA
(RAPD) profiles as a measure of DNA effects were compared with control which showed many differences. In
conclusion, the measurement of parameters at molecular levels is valuable for investigating the specific effects of agents
interacting with DNA.