The antimicrobial effects of Polypropylenimine-G2 and Polyamidoamine-G4 Dendrimers on Klebsiella oxytoca, Pseudomonas aeruginosa and Proteus mirabilis, in vitro experiment

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. 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. Zone of inhibition in concentration 500 μg/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 μg/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 μg/ml. Also, the MIC of PPI-G2 dendrimer for Proteus mirabilis was 50 μg/ml. The MBC of PPI-G2 dendrimer for Klebsiella oxytoca was 50 μg/ml and it was 500 μg/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 μg/ml, respectively. The MBC of PAMAM-G4 dendrimer belonged to Klebsiella oxytoca and Proteus mirabilis were 1250 and 2500 μg/ml, respectively. 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.