Razi Journal of Medical Sciences

  Background : Silver nanoparticles have wide applications in medicine and treatment of bacterial infections due to their disinfection properties. Chemical synthesis, biosynthesis and antibacterial properties of silver nanoparticles have been studied previously, but regarding the high costs of chemical synthesis and the increase of antibiotic-resistance phenomenon among bacteria, assessment of the biosynthesis of silver nanoparticles and their effects on different clinical and standard bacterial strains is of great importance.

  Methods: Silver nanoparticles were synthesized through chemical and biosynthesis methods and their size and size distribution was assessed Transmission Electron Microscope. Chemically synthesized nanoparticles were added to tubes containing TSB medium and different bacterial strains for their antibacterial effects and their minimum inhibitory concentration was calculated

  Results: Chemically synthesized silver nanoparticles had high monodispersity, but biosynthesized nanoparticles had higher polydispersity. Smaller silver nanoparticles had better antibacterial effects on Gram-negative and Gram-positive bacteria, in such a manner that they inhibited the bacterial growth at 0.2 mM concentration, but larger nanoparticles had lesser effects.

  Conclusion: Biosynthesis through bacterial supernatant is cost effective, but it produces polydisperse nanoparticles. Silver nanoparticles can replace antibiotics due to their suitable antibacterial effects, but it should be mentioned that clinical strains are more resistant than standard strains and bacterial resistance to these nanoparticles should be checked before their prescription.