Print Edition: July 3, 2013
Silver has long been the first line of defence against werewolves, but it turns out the precious metal might be just as effective in fighting bacteria.
The element (which currently hits the market at around $20 per ounce) has long been rumoured to have anti-bacterial properties; hundreds of years ago, it was common knowledge that water kept in a silver pitcher wouldn’t get scummy as quickly as other standing water.
Researchers have yet to document the power of silver over scummy water, but in a paper published earlier this month, researchers Jose Ruben Morones-Ramirez, Jonathan Winkler, Catherine Spina and James Collins noted the positive effect of silver in fighting certain types of bacteria.
The conclusions of the paper are summed up neatly in the title: “Silver Enhances Antibiotic Activity Against Gram-Negative Bacteria.”
Bacteria can be split into two categories: gram-negative and gram-positive. Gram-negative bacteria types are typically harder to fight since they have an extra cell wall layer. Gram-positive bacteria have only one wall, so are more susceptible to antibiotics. Silver basically weakens these cell walls, which is effective in fighting both cell types, but is especially helpful in breaking down gram-negative bacteria.
As the researchers discovered, silver isn’t capable of killing bacteria on its own; rather, the metal weakens cells enough that antibiotics can swoop in for the kill. This is especially good news considering that many strains of bacteria have become resistant to antibiotics – but have no defence against silver.
“Resistance is growing, while the number of new antibiotics in development is dropping,” Collins noted in a Scientific American article. “We wanted to find a way to make what we have work better.”
Silver attacks bacteria structure in a couple of ways. It bonds to sulphur, which bacteria use to keep proteins in the correct folded structure.
Bacteria also react to silver by producing something called “reactive oxygen species” – a product that further damages the cell walls and also attacks the DNA of the bacteria cell.
Overall, the bacteria comes out worse for wear. Once silver comes into contact with the cells, fewer antibiotics are needed to fight infection, they fight it more effectively, and they are more likely to be successful against antibiotic-resistant diseases like E. coli.
So while you might not be fighting a werewolf any time soon, you might just find yourself using silver to defend against the next infection you contract.