The Antibacterial Effect of Polypropylenimine-G2 Dendrimer on Escherichia coli, Enterobacter cloacae, Bacillus subtilis, and Staphylococcus aureus

Backgrounds and Dendrimers are a new class of synthetic macromolecules, which have many applications in medical sciences. This study was carried out with the purpose of investigating the antibacterial effect of polypropylenimine-G2 (PPI-G2) dendrimer on some bacterial species. In this study, the antibacterial effects of PPI-G2 dendrimer were studied by disk diffusion and microdilution method. PPI-G2 dendrimer in concentrations of 0.5, 5, 50, and 500µg/ml were inoculated onto blank disks and placed in Mueller-Hinton agar media. Zone of inhibition was investigated by bacterial inoculation according to the McFarland standard 0.5. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PPI-G2 dendrimer in the concentrations of 0.05, 0.5, 5, 50, and 500µg/ml, were determined using microdilution method in nutrient broth media. In this study, antibacterial activity of dendrimer increased with increasing their concentration in the disk. Zone of inhibition in the concentration of 500μg/ml for E. coli, Enterobacter cloacae, Bacillus subtilis, and Staphylococcus aurous were 19, 20, 25, and 21mm, respectively. The MIC for Enterobacter cloacae, Bacillus subtilis, and Staphylococcus aurous was 5μg/ml and for E. coli was 500μg/ml. In addition, the MBC for Bacillus subtilis and Staphylococcus aurous was 50μg/ml and for E. coli and Enterobacter cloacae was 500μg/ml. The findings of this study showed that PPI-G2 dendrimer has antibacterial effects. However, use of the dendrimer for drinking water disinfection requires further and wider studies.