Rampant use of antibacterial nanosilver is a resistance risk

Rampant use of antibacterial nanosilver is a resistance risk
Credit: University of Technology, Sydney

Researchers at the University of Technology Sydney warn that the broad-spectrum antimicrobial effectiveness of silver is being put at risk by the widespread and inappropriate expansion of nanosilver use in medical and consumer goods.

As well as their use in medical items such as wound dressings and catheters, silver nanoparticles are becoming ubiquitous in everyday items, including toothbrushes and toothpaste, baby bottles and teats, bedding, clothing and household appliances, because of their antibacterial potency and the incorrect assumption that ordinary items should be kept "clean" of microbes.

Nanobiologist Dr Cindy Gunawan, from the ithree institute at UTS and lead researcher on the investigation, said alarm bells should be ringing at the commercialisation of use because of a "real threat" that resistance to nanosilver will develop and spread through microorganisms in the human body and the environment.

Dr Gunawan and ithree institute director Professor Liz Harry, in collaboration with researchers at UNSW and abroad, investigated more than 140 commercially available medical devices, including wound dressings and tracheal and urinary catheters, and dietary supplements, which are promoted as immunity boosters and consumed by throat or nasal spray.

Their perspective article in the journal ACS Nano concluded that the use of nanosilver in these items could lead to prolonged exposure to bioactive silver in the . Such exposure creates the conditions for microbial resistance to develop.

The use of silver as an antimicrobial agent dates back centuries. Its ability to destroy pathogens while seemingly having low toxicity on human cells has seen it widely employed, in treating burns or purifying water, for example. More recently, ultra-small (less than 10,000th of a millimetre) have been engineered for antimicrobial purposes. Their commercial appeal lies in superior potency at lower concentrations than "bulk" silver.

"Nanosilver is a proven whose reliability is being jeopardised by the commercialisation of people's fear of bacteria," Dr Gunawan said.

"Our use of it needs to be far more judicious, in the same way we need to approach antibiotic usage. Nanosilver is a useful tool but we need to be careful, use it wisely and only when the benefit outweighs the risk.

"People need to be made aware of just how widely it is used, but more importantly they need to be made aware that the presence of nanosilver has been shown to cause antimicrobial resistance."

What is also needed, Dr Gunawan said, is a targeted surveillance strategy to monitor for any occurrence of resistance.

Professor Harry said the findings were a significant contribution to addressing the global antimicrobial resistance crisis.

"This research emphasises the threat posed to our health and that of the environment by the inappropriate use of nanosilver as an antibacterial, particularly in ordinary household and consumer items," she said.

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More information: Cindy Gunawan et al. Widespread and Indiscriminate Nanosilver Use: Genuine Potential for Microbial Resistance, ACS Nano (2017). DOI: 10.1021/acsnano.7b01166
Journal information: ACS Nano

Citation: Rampant use of antibacterial nanosilver is a resistance risk (2017, March 31) retrieved 18 October 2019 from https://phys.org/news/2017-03-rampant-antibacterial-nanosilver-resistance.html
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Mar 31, 2017
I have friends that create nanosilver in water and spray that stuff on themselves whenever there is the slightest hint of anything occuring on their skin. From cuts to scraps to rashes, start spraying the silver. They spray it into their throats for a cough or a tickle in there. They also drink it daily to help their "health" apparently. Lastly, they go through litres of this stuff almost every day. And they have a plethora of health problems. Cause or effect?

Mar 31, 2017
Prescription of low (starter-dose) antibiotics to people where it will never create a therapeutic dose through a bio-film.
Dosing animals with continuous antibiotics so it gets into farm effluent.
Antimicrobial hand wash going into drainage.
These too combine to feed resistance.

Reluctance to prescribe combinations of antibiotics where this has been shown to be multiply effectiveness (even against MRSA): This causes each single antibiotic resistance to be additive in the bacterial population.


Apr 01, 2017
You can actually get blue skin (Argyria) by overuse of nanosilver. The silver changes in the body to form argyrial deposits.

Apr 03, 2017
Appalling. Unconscionable, "anything for a buck" commercialism with no thought for the long term effects on human health or well-being. The antimicrobrial effectiveness of nanosilver seems doomed to suffer the same fate of resistant strains emerging as is seen with antibiotics, thanks to the widespread inappropriate use of antibiotics in agriculture for the past half century. When will we ever learn?

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