The antimicrobial activity of silver nanoparticles in vitro

Silver nanoparticles possess a high potential as an antimicrobial substance against a wide spectrum of bacteria, including antibiotic-resistant strains. Antimicrobial properties of silver nanoparticles with 30 nm in diameter synthesized according to the original protocol have been determined in this study. In in vitro study using the serial dilutions method in the solid medium the minimal inhibition concentration (MIC) of silver nanoparticles against such test-strains as Staphylococcus aureus MRSA ATCC 43300, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 2592, Shigella sonnei, Salmonella typhimurium 144 was equal to 33.46 μg/ml. MIC against B. subtilis ATCC 6633 was 133.8 μg/ml. The antimicrobial activity of silver nanoparticles has been studied on clinical isolates with multiple drug resistance isolated from wounds, urine, endocervical and faucial scrapings in surgical patients with Klebsiella ozaenae 4348, Citrobacter freundii 4369, Escherichia coli 4358, Enterobacter aerogenes 2476, Proteus mirabilis 4363, Staphylococcus aureus 4312 and Pseudomonas aeruginosa 283. The total inhibition of the microorganisms growth under the action of both doses of silver nanoparticles studied – 10 μg and 20 μg has been observed.