Antibiofilm activity of biosynthesized silver nanoparticles against methicillin resistant Staphyloccoccus aureus isolated from hospitalized patients

Nanoparticles are newly developed substances that have been used in many fields, including medicine, and their biological activities on various pathogens have been proven. Therefore, in this thesis, the effect of tough nanoparticles on Staphyloccoccus aureus, a pathogenic bacteria species, is investigated. In the first phase of the thesis study, bacterial isolates were obtained by taking samples from 100 patients hospitalized in Al-Emamein Kadhimein Medical Center. 39% of these clinical S. aureus isolates were identified as MRSA due to methicillin resistance. Methicillin-resistant isolates were examined for biofilm formation, and it was determined that 100% of all isolates had biofilm producing abilities. Escherichia coli was isolated from food samples. Then, silver nanoparticles were sunthesized using E. coli from these foods. The formation of AgNPs was visually observed before identification by UV-VIS spectroscopy and atomic force microscopy, indicating an average diameter of 57.53 nm for biosynthesized AgNPs. Optimization of AgNP synthesis by E. coli was performed for several parameters and the results revealed that 1:3 reaction mixture, temperature 37°C, 24 hours were optimum conditions. The biosynthesis of AgNPs by foodborne E. coli, the efficacy of silver nanoparticles as an antibacterial approach was evaluated against clinical MRSA isolates.