In vitro Antibacterial Effects of Salvia sclarea, Eucalyptus Globulus and Eugenia Caryophyllata Essential oils Against Multidrug Resistant Corynebacterium spp Clinical Isolates

Abstract

Objectives: Multidrug resistant Corynebacterium species are increasingly reported as the ethiological agent of various clinical infections. Thus, the purpose of this research was to evaluate the in vitro antimicrobial activity of three essential oils Salvia sclarea, Eucalyptus globulus and Eugenia caryophyllata against Corynebacterium species. Methods: Twenty-four multidrug resistant strains including C. striatum, C. amycolatum, C. urealyticum, C. aurimucosum, C. imitans, and C. jeikeium were used in the study. Inhibition diameter zone, minimum inhibitory concentration and minimum bactericide concentration of these oils were determined using agar disc diffusion method and microdilution method. Tigecycline was used as positive control. Results: Our study showed that Eugenia caryophyllata had the best activity. Eucalyptus globulus extract exhibited a moderate activity and Salvia sclarea was inactive against all the species tested. We found that C. amycolatum was more resistant to the essential oils than other species. On the other hand, tigecycline was effective on the majority of the strains (37.5%), but his action was lower than Eugenia caryophyllata oil. Conclusion: These results support the use of clove oil as a natural alternative to treat infections caused by multidrug resistant corynebacteria.