The Antimicrobial Activity of Thyme, Sweet Marjoram, Savory and Eucalyptus oils on Escherichia coli, Salmonella typhimurium, Aspergillus niger and Aspergillus flavus

Background: The presence of pathogenic microorganisms in aviculture threatens the health of fowl and humans. Thyme (Zataria multiflora Boiss), sweet marjoram (Origanum majorana), savory (Satureja hortensis) and eucalyptus (Eucalyptus globules) are Iranian herbal medicines that are used in folk medicines. Objective: The aims of this study were to evaluate the antimicrobial activity of these oils separately and in combination against Escherichia coli, Salmonella typhimurium, Aspergillus niger and Aspergillus flavus in vitro condition. Methods: The antimicrobial activity of essential oils against different isolates of microorganisms was evaluated by disc diffusion and macro broth dilution assays. Results: The results showed that the antimicrobial activity of thyme, sweet marjoram and savory oils against different bacteria and fungi were more than the eucalyptus oil. When ethanol was used as a solvent in comparison with dimethyl sulfoxide, the antimicrobial activity of oils was increased. The type of solvent creates meaningful discrepancy on effectiveness of oils (p