Amirreza Akbari - Departement of Microbiology, Ilam Branch,Islamic Azad University,Ilam,Iran
Tayeb Seifi - Veterinary Laboratory Science Expert, Ilam University, Faculty of Veterinary Medicine
Reza Alizadeh - Departement of Veterinary Laboratory Sciences, Ilam University, Faculty of Veterinary Medicine
Bahareh Shah Ali - Departement of Microbiology, Ilam Branch,Islamic Azad University,Ilam,Iran
Roya Rasouli - Departement of Food Health, Ilam University, Faculty of Veterinary Medicine
Zeinab Safari - Departement of Food Health, Ilam University, Faculty of Veterinary Medicine

Background and Aim : Background and purpose: Improper use of chemical drugs to treat diseases has led to the emergence of resistant microbial isolates, and bacterial resistance to antibiotics is one of the most common problems in medical and veterinary sciences. Gold nanoparticles are targeted thermal agents that have many applications in medical and pharmaceutical treatments and have a high accuracy of thermal effects in subcellular dimensions. In this study, the antibacterial effect of gold nanoparticles on seven pathogenic bacteria Escherichia coli, Klebsiella Oxy Toka, Citrobacter Frondy, Enterobacteriaceae, Staphylococcus aureus, Bacillus cereus, and Streptococcus agalactia was evaluated in laboratory conditions.Methods : Materials and Methods: In this study, gold nanoparticles in different concentrations were applied to the bacterium using agar diffusion method and tetracycline and gentamicin antibiotics as positive control and from DMF negative control. The minimum inhibitory concentration and the minimum lethal concentration were determinedResults : Results: In this study, the results showed antibacterial effects of gold nanoparticles on ۷ bacteria, and the most sensitive was showed in Escherichia coli with the highest diameter of non-growth zone (۲۵ mm) and MIC was(۱۰۰ mg-mg / m)l. And the Staphylococcus aureus bacterium was(۲۲ mm) and the MIC was (۲۰۰ mm).Conclusion : Conclusion: The results of this study showed that gold nanoparticles have a growth inhibitory effect on all seven bacteria and have the greatest inhibitory effect on Escherichia coli and Staphylococcus aureus bacteria.

Keywords: Gold nanoparticles, antibacterial effect