antibacterial activity of mentha longifolia against salmonella typhimurium

background and aims: traditionally, plants have long been applied in the treatment of various diseases throughout the history of human life. the antimicrobial activity of plant extracts in the laboratory is studied on gram positive and negative strains of human infectious agents. the aim of this study was to evaluate the antibacterial activity of mentha longifolia against important human pathogens. methods: this was an experimental study and no statistical method was used. the antimicrobial effect of ethanol extracts of mentha longifolia were investigated on salmonella typhimurium were determined using broth microdilution method. the broth microdilution method was used to determine the minimal inhibitory concentration (mic) and the minimum bactericidal concentration (mbc). all tests were performed in mueller hinton broth supplemented with tween 80 at a final concentration of 0.5%. results: the results showed that the lowest mic concentration was 5 mg/ml that 1 strain of salmonella was inhibited. the highest and the lowest mbc values of extract were 40 and 10 mg/ml, respectively. conclusion: since the antibiotic resistant bacteria are increasing in the world, replacing the chemical and synthetic antibiotics with natural products is essential. it can be concluded from the results of this study that using herbal plant instead of antibiotics can resolve some antibiotic resistant problems.