ABSTRACT
Background: This laboratory experiment was aimed of to investigate the antibacterial effect of Polypropylenimine-G2 [PPI-G2] and Polyamidoamine-G4 [PAMAM-G4] dendrimers on Klebsiella oxytoca, Pseudomonas aeruginosa and Proteus mirabilis.
Materials and Methods: Different concentrations of PPI-G2 and PAMAM-G4 dendrimers were inoculated onto Blank disks and were 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 and PAMAM-G4 dendrimers were determined by Micro-dilution method in nutrient broth culture.
Results: Zone of inhibition in concentration 500 MICRO SIGNg/ml of PPI-G2 dendrimers for Klebsiella oxytoca, Proteus mirabilis and Pseudomonas aeruginosa were 25, 15 and 20mm, respectively. Zone of inhibition in concentration 500 MICRO SIGNg/ml of PAMAM-G4 dendrimers for Klebsiella oxytoca, Proteus mirabilis and Pseudomonas aeruginosa were 20, 18 and 0mm, respectively. The MIC of PPI-G2 dendrimer for Klebsiella oxytoca and for Pseudomonas aeruginosa were 5 MICRO SIGNg/ml. Also, the MIC of PPI-G2 dendrimer for Proteus mirabilis was 50 MICRO SIGNg/ml. The MBC of PPI-G2 dendrimer for Klebsiella oxytoca was 50 MICRO SIGNg/ml and it was 500 MICRO SIGNg/ml for Proteus mirabilis and Pseudomonas aeruginosa. The MIC of PAMAM-G4 dendrimer attributed to Klebsiella oxytoca and Proteus mirabilis were reported 500 and 1250 MICRO SIGNg/ml, respectively. The MBC of PAMAM-G4 dendrimer belonged to Klebsiella oxytoca and Proteus mirabilis were 1250 and 2500 MICRO SIGNg/ml, respectively.
Conclusion: According to the results, PPI-G2 dendrimers can eliminate Pseudomonas aeruginosa, Klebsiella oxytoca and Proteus mirabilis effectively but PAMAM-G4 only has antibacterial effect against Klebsiella oxytoca and Proteus mirabilis. Also the antibacterial activity of PPI-G2 dendrimer is obviously better than those of PAMAM-G4. However, using dendrimers can be considered as a new approach for drinking water disinfection but it requires further wide range studies.
ABSTRACT
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 500microg/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 500microg/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 500microg/ml for E. coli, Enterobacter cloacae, Bacillus subtilis, and Staphylococcus aureus were 19, 20, 25, and 21mm, respectively. The MIC for Enterobacter cloacae, Bacillus subtilis, and Staphylococcus aureus was 5microg/ml and for E. coli was 500microg/ml. In addition, the MBC for Bacillus subtilis and Staphylococcus aurous was 50microg/ml and for E. coli and Enterobacter cloacae was 500microg/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