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

Abstract

Backgrounds and Objectives:Dendrimers are a new class of synthetic macromolecules, which have many applications in medical sciences.This study was carried out with the purpose ofinvestigating the antibacterial effect of polypropylenimine-G2 (PPI-G2) dendrimer on some bacterial species. Methods: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. Results: 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 aurouswere 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. Conclusion: 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.

Keywords

• poly(propyleneimine)
• anti-bacterial agents
• microbial sensitivity tests
• minimum bactericidal concentration
• zone of inhibition.