Synthesis of silver nanoparticles functionalized with aqueous extract (burseragraveolens) and antimicrobial evaluation in Escherichia coli, staphylococcus aureus and klebsiellapneumoniae

Currently, resistance to antibiotics has become a problem for the treatment of infectious diseases. In this study, silver nanoparticles were synthesized using the aqueous extract of Palo santo (Burseragraveolens), for its biocide action, in order to determine its antimicrobial effect on Escherichia coli and Staphylococcus aureus. Different concentrations of nanoparticles (100 until1000 ppm) were evaluated at contact times of 1, 2, 5 and 10 minutes for 1500 and 15000 CFU/mL. Additionally, to determine effectiveness, disc diffusion tests using various concentrations of nanoparticles (500-1000 ppm) were performed on S.aureus and K. pneumoniae. According to the results of antimicrobial effect for E.coli, the effectiveness of nanoparticles can be established at all contact times for 1500 CFU from 800 ppm and for 15000 CFU from 400 ppm. With S.aureus, total inhibition was showed from 800 ppm in 1500 CFU at 5 minutes of contact and between 500-1000 ppm with 15000 CFU at minute one. S. aureus and K.pneumoniae tests showed sensitivity with nanoparticles. The average of susceptibility for S.aureus had the lowest inhibition between 500-600 ppm and the highest at 700-800 ppm. The average susceptibility for K. pneumoniae is more constant in terms of inhibition at 600-1000 ppm. This study demonstrated the antimicrobial effect of silver nanoparticles synthesized under the specified conditions.