Power of silver as an antimicrobial

                                         Source: By Ivar Leidus - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=100038049

Antimicrobials are used to kill or slow the growth of bacteria, viruses and other microorganisms. They are essential to preventing and treating infections, but they also pose a global threat to public health when microorganisms develop antimicrobial resistance. A lab studied the mechanisms behind bacterial resistance to silver nanoparticles to determine if their ubiquitous use is a solution to this challenge or if it is perhaps fueling the fire.

 

One of the main drivers of antimicrobial resistance is the misuse and overuse of antimicrobial agents, which includes silver nanoparticles, an advanced material with well-documented antimicrobial properties. It is increasingly used in commercial products that boast enhanced germ-killing performance -- it has been woven into textiles, coated onto toothbrushes, and even mixed into cosmetics as a preservative.

 

The Gilbertson Group at the University of Pittsburgh Swanson School of Engineering used laboratory strains of E.coli to better understand bacterial resistance to silver nanoparticles and attempt to get ahead of the potential misuse of this material. The team recently published their results in Nature Nanotechnology.

 

The group sequenced the genome of the E.coli that had been exposed to silver nanoparticles and found a mutation in a gene that corresponds to an efflux pump that pushes heavy metal ions out of the cell.

 

 

The group then studied two different types of E.coli: a hyper-motile strain that swims through its environment more quickly than normally motile bacteria and a non-motile strain that does not have physical means for moving around. They found that only the hyper-motile strain developed resistance.

 

In the end, bacteria will still find a way to evolve and evade antimicrobials. The hope is that an understanding of the mechanisms that lead to this evolution and a mindful use of new antimicrobials will lessen the impact of antimicrobial resistance.

 

Journal Reference:

 

Lisa M. Stabryla, Kathryn A. Johnston, Nathan A. Diemler, Vaughn S. Cooper, Jill E. Millstone, Sarah-Jane Haig, Leanne M. Gilbertson. Role of bacterial motility in differential resistance mechanisms of silver nanoparticles and silver ions. Nature Nanotechnology, 2021; DOI: 10.1038/s41565-021-00929-w

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)