Background: It is well-known that silver ions and silver compounds are broad-spectrum antimicrobial agents effective against gram-positive and gram-negative bacteria, and yeasts. Thus, silver ions, as an antibacterial agent, have been used in the components of materials used in medical devices or coatings. Recently, advances in nanotechnology have enabled manufacturers to develop silver particles of a nanometer size with a safer and more effective antimicrobial activity. So, we evaluate the antimicrobial activity of nanoSilver-coated gauze against clinical isolates. 

Methods: Three kinds of nanoSilver-coated gauzes (100Å, 800Å, and 1,500Å) were tested for antimicrobial activity by the disk diffusion method. The organisms tested included clinical isolates of nonfermentative gram-negative bacilli (143 isolates), aerobic gram- negative bacteria (188), aerobic gram-positive bacteria (397), anaerobic bacteria (46), and yeasts (161), and three reference ATCC strains. 

Results: The susceptible rates to NanoSilver of nonfermentative gram-negative bacilli (NFB), aerobic gram- negative bacteria and aerobic gram-positive bacteria were 87%, 87% and 78%, respectively. Antimicrobial activity of NanoSilver against imipenem-resistant NFB, extended spectrum β-lactamase (ESBL) producing Enterobacteriaceae, and methicillin-resistant Staphylcoccus aureus (MRSA) was similar to that against imipenem-sensitive NFB, ESBL non-producing Enterobacteriaceae, and methicillin-susceptible S. aureus. 

Conclusion: NanoSilver-coated gauze exhibits broad spectrum antimicrobial activities to a large number of gram-negative and gram-positive bacteria including imipenem-resistant NFB, ESBL producing Enterobacteriaceae, and MRSA. (Korean J Clin Microbiol 2007;10:37-43)