Summary:

The aim of the study was to evaluate the bactericidal properties of silver nanoparticles against bacteria Escherichia coli. In addition, a sensitivity analysis was made of E. coli to commonly used antibiotics. In the study were used 51 strains isolated from municipal waste. Applied growing concentrations of nanosilver were used: 5, 10, 15, 30, 60 and 125 ppm. The positive control was an antibiotic - ampicillin, negative control - a distilled water. Drug-resistance analysis was performed by disc-diffusion method. Along with the increase in the concentration of silver nanoparticles their antibacterial properties is also growing. The smallest concentration that inhibited growth of some isolates was 5 ppm, while the most effective concentration was 125 ppm. Analysis of drug resistance showed that the antibiotic inhibits growth of a large number of E. coli strains was amikacin. In addition, 22% of all isolates analyzed were drug-resistant. Nanosilver has a high bactericidal potential and may be helpful in solving the problem of drug resistance. However, it is reasonable to conduct further studies on the effects of toxicity of nanoparticles on the environment and higher organisms.