Farzaneh Firoozeh - Associate professor, Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, IR Iran
Termeh Aziziyan - MSc Student, Department of Biology, Danesh Alborz University, Qazvin, IR Iran
Ali Sobhani-Nasab - Assistant professor, Institute of Nano Science and Nano Technology, University of Kashan, Kashan, IR Iran
Mohammad Zibaei - Professor, Department of Parasitology and Mycology, School of Medicine, Alborz University of Medical Sciences, Karaj, IR Iran
Afshar Etemadi - PhD Student, Department of Microbiology, School of Medicine, Kashan University of Medical Sciences, Kashan, I.R. Iran

Introduction and Objectives: Escherichia coli and Staphylococcus aureus are the most common causes of hospital- and community-acquired infections and antimicrobial resistance among them has become a major health problem. Recently nanoparticles are among the compounds that have been most noticed due to their antimicrobial properties. It has been shown that the production of nanoparticles by using plant extracts leads to the acquisition of nanoparticles with increased antimicrobial activity. The purpose of current study was to evaluate antibacterial effects of combination of silver nanoparticles and extracts of Ghalghaf gall against the mentioned bacteria. Materials and Methods: In this study silver nanoparticles were synthesized using extracts of Ghalghaf gall. Antibacterial activity of these nanoparticles against the standard strains of Escherichia coli and Staphylococcus aureus were evaluated by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values by broth macro-dilution method according to Clinical and Laboratory Standards Institute (CLSI) procedures. Results: The MIC and MBC values of the combination of silver nanoparticles and extracts of Ghalghaf gall obtained for Escherichia coli were 78 μg/ ml and 156 μg/ ml respectively. The observed MIC and MBC values of the mentioned combination for Staphylococcus aureus were 156 μg/ ml and 1250 μg/ ml. Conclusion: According to the results of current study, the combination of silver nanoparticles and extracts of Ghalghaf gall showed remarkably higher antibacterial effects compared to silver nanoparticles alone especially against Escherichia coli.

Antibacterial activity, Silver nanoparticles, Ghalghaf gall, Escherichia coli, Staphylococcus aureus