Abstract

Plant extracts and their phytochemicals with antibacterial properties can be influential on infection treatment. In the present study, inhibitory activity of aqueous and ethanol 90 extracts of Zataria multiflora, Thymus vulgaris, Mentha pulegium, Mentha piperita, Ocimum basilicum, Cassia senna, and Carthamus tinctorius on the growth of Escherichia coli isolated from diseased chickens were tested in vitro using disk diffusion method. Inhibition zone diameters of bacterium were calculated in the presence of the plants extract. All the ethanol 90 extracts with concentration of 0.2-1.0 mg/mL effectively inhibited the growth of the bacterium, while aqueous extracts showed no activity against E. coli. Inhibition zone diameters (IZD) of the bacteria treated with different concentrations of ethanol 90 extracts of the plants raging between 14.6-41.0 mm. Zataria multiflora and M. pulegium with concentration of 1.0 mg/mL exhibited highest antibacterial activity compared with other plants with IZDs of 41.0 +/- 0.0 and 39.0 +/- 0.0 mm, respectively. According to the results, the order of inhibitory effect of plants extract with concentration of 1.0 mg/mL against E. coli was Z. multiflora> M. pulegium> T. vulgaris> M. piperita> C. angustifolia> C. tinctorius> O. basilicum. Our findings revealed that the tested plants could be considered as suitable source of phytochemicals for prevention of E. coli growth. The extracts of the examined plants are suitable supplementary alternative for control of E. coli in laying hens.