Leila Karami

Abstract Background: Researchers are seeking new plant compounds as an alternative to chemical drugs and antibiotics due to the increasing resistance of pathogenic bacteria to antibiotics. This study investigated the antibacterial effect of Plantago ovata and Lallemantia iberica L. seed extracts on some foodborne human pathogenic bacteria. Materials and Methods: Disk-diffusion antibiotic sensitivity testing, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were used to evaluate the antibacterial activity of plant extracts in comparison to the tetracycline, as a control antibiotic. Results: The results of this experiment showed that the L. iberica seed extract had the greatest effect on Bacillus subtilis, Bacillus sphaericus and Pseudomonas aeruginosa and did not have inhibitory effect or moderate inhibitory effect against other bacteria. Also, P. ovata extract had a high and moderate effect against Bacillus sphaericus and Pseudomonas aeruginosa, respectively. This extract had no inhibitory effect on the other bacteria. Tetracycline also had a significant inhibitory effect on all tested bacteria. Conclusion: According to the results of this study, it can be concluded that extracts of some Iranian native plants can be a suitable alternative to the existing antibiotics.