Antibacterial Effect of Nano Polyamidoamine-G7 Dendrimer on Clostridium perfringens, Bacillus subtilis, Salmonella typhi, and Shigella dysenteriae in Aqueous Solution

A large number of studies has been conducted on applications of Polyamidoamine dendrimers, but their antibacterial activity has not been investigated extensively. The purpose of this study was synthesis and determining the antibacterial effect of nano polyamidoamine-G7 (NPAMAM-G7) dendrimer in the removal of Clostridium Perfringens, Bacillus Subtilis, Salmonella typhi, and Shigella dysenteriae bacteria from aqueous solution.
This experimental study was conducted in microbiology laboratory of Iran University of Medical Sciences (autumn and winter 2015). Initially, dilution of 103CFU/ml was prepared from each strain of bacteria. Then, different concentrations of dendrimer (0.025, 0.25, 2.5, and 25µg/ml), were added to water at laboratory temperature (23-25°C). In order to determine the efficiency of dendrimers in the removal of bacteria, sampling were performed at different times (0, 10, 20, 30, 40, 50, and 60min), and were cultured on specific medium for each bacterium.
In this study, the antibacterial property of dendrimer in aqueous solution had direct relationship with increasing concentration of dendrimer and contact time. The concentration of 25 μg/ml of dendrimer at contact times of 30, 50, and 60 min, 100% removed bacteria Salmonella typhi and Bacillus Subtilis and at contact time of 60 min, 100% and 98% removed Clostridium Perfringens and Shigella Dysenteriae bacteria, respectively, from aqueous solution. The concentration of 2.5μg/ml at 30, 50, and 60 min contact times, 100% removed Bacillus Subtilis.
The findings of this study revealed that Polyamidoamine-G7 dendrimers possess appropriate antimicrobial activity against Gram-positive and Gram-negative bacteria.