Synergism between essential oils and antimicrobial drugs against Staphylooccus aureus and Escherichia coli strains from human infections

The studies with plants and combinatory therapy have been stimulated. The interactions between cinnamon (Cinnamomun zeylanicum Blume Lauraceae), lemon grass (Cymbopogon citratus (DC.) Stapf, Poaceae), mint (Mentha piperita L. Lamiaceae), ginger (Zingiber officinale Roscoe Zingiberaceae), clove (Caryophillus aromaticus L. Myrtaceae) and rosemary (Rosmarinus officinalis L. Lamiaceae) and eight antimicrobial drug was carried. It was made against twelve S. aureus and twelve E.coli strains isolated from human specimens. After minimal inhibitory concentration (MIC) values determination of essential oils by dilution agar method, the synergism assays were performed by Kirby and Bauer method. The S. aureus was susceptible to oils and drugs interactions, and the lemon grass oils showed synergism with all drugs tested followed by mint with seven drugs. E.coli assays, synergism was observed only with rosemary (three drugs) and lemon grass (two drugs). No antagonism between drugs and oils tested was observed and the results were variable according to microorganism used.

Antimicrobial drugs; bacteria; essential oils; medicinal plants; synergism