Materials and Methods: After collecting the mentioned plants phytology study was done. Then methanol extracts of named plants were prepared and antibacterial effects of these plants against the mentioned strain of L. monocytogenes by the Disk Diffusion, minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) methods were performed. Also Ampicillin (10 μg/disc) was used as the reference antibacterial substance. In order to find the relationship between antibacterial properties of plants extracts independent t test, chi-square and analysis of variance (ANOVA) tests were used.

Results: Results showed that the extracts of all the three studied plants had antibacterial effects on L. monocytogenes. Average diagonal of growing area in disk diffusion test for barberry, kiwi and onions in order was 12, 15.5 and 11 mm. Also MIC of mentioned plants extracts in order was 125, 62.5, and 125 μg/ml and MBC of named plants was 500, 250 and 500 μg/ ml, respectively.

Conclusion: The results of this work showed that methanol extracts of kiwi had stronger anti-Listerial effect than barberry’s and onion’s extracts.