synthesis, characterization and antimicrobial activity of bacillussubtilis-derived silver nanoparticles against multidrug-resistant bacteria

Background: silver nanoparticles (agnps) have received great attention in the biomedical field because of their intrinsic therapeuticproperties. nanoparticles synthesized from silver have been studied as antimicrobial, antiviral and anticancer agents and foundparticularly an attractive source for the development of a new and advance group of antimicrobial agents.objectives: in the present study, silver nanoparticles were synthesized from non-pathogenic bacillus subtilis strain to assess theirantimicrobial activity.methods: different strains of bacillus spp. were selected and screened against silver nitrate (agno3) toxicity. finally, b. subtilis strain(fcbp-wb-0174) was selected based on its silver resistant nature, among other strains. silver nanoparticles were synthesized andoptimized from the supernatant of b. subtilis culture at 37°c by the reduction of silver ions using the various molar concentrationof agno3. the synthesized agnps were characterized by uv-vis spectrophotometry and scanning electron microscopy (sem). thesesynthesized agnps were used for evaluating antimicrobial activity against four multidrug-resistant bacterial strains.results: the silver ion reduction was found at a ratio of 1:1 from all the three molar concentrations (1, 2, and 3 mm) of agno3. thecharacterized nanoparticles were found to have a characteristic absorption peak at 426 nm, and the particles were found to havespherical shape under sem with an average diameter of about 80  0.18 nm, which was also reconfirmed using zeta sizer nano.prepared silver nanoparticles have found potential antimicrobial activities against all tested pathogenic, including strains, e.g.,acinetobacter baumannii, pseudomonas aeruginosa, methicillin-resistant staphylococcus aureus(mrsa) and escherichia coli.conclusions: effective agnp’s were produced from selected b. subtilis strain, and the strain itself was resistant toagno3. the currentstudy evidenced that biologically synthesized silver nanoparticles from b. subtilis has promising antimicrobial activities againstpathogenic and multidrug-resistant bacteria.