Shahrekord University of Medical Sciences Future Natural Products 2783-4662 3 1 2017 01 31 Antimicrobial activities of Gold nanoparticles against Salmonella typhimurium 26 30 EN Farzaneh Ghanavati Behbahan Mohammad Salari Seyedeh Razeyeh Mousavi Razeyeh Rezaei Journal Article 2015 12 12 2016 04 24 Background and aims: One of the major problems in hospitals is resistant pathogenic bacteria to antimicrobial substances. The problem of increased costs of treatment failure and mortality rates is increasing. The aim of this study was to evaluate the antimicrobial activity of gold nanoparticles has been on Salmonella typhimurium. Methods: This cross-sectional study was performed and Salmonella typhimurium bacteria were isolated from poultry. Gold nanoparticles for business were purchased. Minimum inhibitory concentrations of gold nanoparticles in different concentrations by dilution in the wells were determined on bacteria. Susceptibility to several antibiotics was evaluated by Kirby-Bauer disk diffusion method. Results: The result of gold nanoparticles showed the highest MIC (the minimum inhibitory concentration) was 100 ppm concentration that 6 strains of them were inhibited by this concentration. The lowest MIC was 50 ppm concentration that 1 strain of Salmonella was inhibited. The highest and lowest MBC value of extract was 200 and 100 ppm, respectively. Conclusions: The results showed that gold nanoparticles have good inhibitory effect on all studied bacteria. onclusions: The results showed that gold nanoparticles have good inhibitory effect on all studied bacteria.