Antibacterial activity of nanoparticles against multi-drug resistant Staphylococci

Abstract

1- Sixteen isolates of Actinobacteria were recovered from soil samples collected from two different locations from Libya and Egypt. All isolates were examined for their ability to reduce silver ions to produce silver nanoparticles (Ag-NPs) using extracellular metabolic products. The sixteen isolates showed different ability to reduce silver ions, and isolate E-37 was the most potent isolate in the production of reducing compounds and thus the best producer of Ag-NPs. The isolate E-37 was characterized by different cultural, microscopical, biochemical, and molecular methods. The results of all tests indicate that the isolate E-37 belongs to the Streptomyces genus, the species of S. rochei. In this work, it was referred to as S. rochei strain MFA-37. 2- Ag-NPs were biosynthesized by S. rochei strain MFA-37 and Ag-NPs were characterization by UV-vis spectrophotometric analysis, Fourier transform infrared (FT-IR) analysis, High-resolution transmission electron microscopy (HRTEM), X-ray Diffraction analysis (XRD), and Dynamic light scattering (DLS) techniques. The results showed that amine and amide were responsible for the stability of these particles. Also, the synthesized nanoparticles were well dispersed, spherical, with a size between 2-20 nm. Zeta potential measurement also indicates that these particles carry a charge that makes them stable in their solutions.