Vida Alizadeh - Department of Biology, Urmia Branch, Islamic Azad University, Urmia, Iran
Bahram Golestani Eimani - Department of Biology, Urmia Branch, Islamic Azad University, Urmia, Iran
Fariba Amjady - Department of Biology, Urmia Branch, Islamic Azad University, Urmia, Iran

Background and objectives: Drug resistance in bacteria is one of the important problems in the antibacterial field. Therefore, new drugs and therapeutic approaches are required to eliminate bacteria using different and novel mechanisms. Among these, the silver nanoparticles have been proposed as a substance with antibacterial properties against gram-positive and gram-negative bacteria. The present study aimed to investigate the effects of silver nanoparticles with a size of less than 20 nm on the genome of Staphylococcus aureus (S. aureus) as a model for gram-positive bacteria. Material and methods: For this purpose, the bacteria were treated at concentrations of 100 and 150μg/ml nanoparticles and antimicrobial properties of the nanoparticles were investigated in intervals of 2, 4 and 24 hours, then DNA was extracted. RAPD molecular marker was used to investigate the effects of nanoparticles on the genome. In addition, the results of electrophoresis for polymerase chain reaction (PCR) products on agarose gel were analyzed. Results: The present findings demonstrated that silver nanoparticles not only have an inhibitory effect on bacteria but also affect the genomic DNA sequence of this bacterium and change it in different sites. Conclusion: The nanoparticles are antibacterial compounds and can be an appropriate alternative to antibiotics.

Genetic Diversity, Growth Inhibition, NTSYS-PC Software, Random Amplified Polymorphic DNA (RAPD-PCR), Silver Nanoparticles