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Updated: May 18, 2026
11:52
Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro
Published on: April 21, 2023
Spectrum of antimicrobial activity associated with ionic colloidal silver.
Kira Morrill1, Kathleen May, Daniel Leek
1Department of Naturopathic Research, Southwest College of Naturopathic Medicine, Tempe, AZ, USA.
Journal of Alternative and Complementary Medicine (New York, N.Y.)
|September 29, 2012
Summary
Ionic colloidal silver effectively inhibits aerobic and anaerobic bacteria growth, though multiple applications may be needed. Its antifungal effects vary by genus, and it shows no efficacy against tested viruses.
Area of Science:
- Microbiology
- Antimicrobial Agents
Background:
- Silver has a long history of use as a broad-spectrum antimicrobial agent.
- The U.S. Food and Drug Administration (FDA) currently does not recognize colloidal silver as safe or effective.
- There is a need for further evaluation of colloidal silver's antimicrobial properties.
Purpose of the Study:
- To evaluate the antimicrobial efficacy of ionic colloidal silver.
- To assess its effectiveness against various bacterial, fungal, and viral strains.
Main Methods:
- Bacterial, fungal, and viral strains were cultured under multicycle growth conditions.
- Cultures were exposed to ionic colloidal silver or a control.
- Antimicrobial activity was assessed by observing growth inhibition.
Main Results:
- Significant growth inhibition of aerobic and anaerobic bacteria was observed, often requiring multiple treatments.
- The efficacy of ionic colloidal silver against fungal genera varied considerably.
- No inhibition of viral growth was detected across any tested strains.
Conclusions:
- Ionic colloidal silver demonstrates broad-spectrum antimicrobial activity against both aerobic and anaerobic bacteria.
- Its activity against fungi is more limited and genus-specific.
- The compound was ineffective against the tested viruses.
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