科学美国人60秒:Silver Shows Its Mettle against Bacteria

If you’re plagued by werewolves, reach for the silver. And more mundane health problems may also respond well to the silver solution. Because a new study shows that microbes exposed to a pinch of the precious metal become more vulnerable to antibiotic attack. The research is in the journal Science Translational Medicine. [Jose Ruben Morones-Ramirez et al., Silver Enhances Antibiotic Activity against Gram-Negative Bacteria]

Silver’s long been a medical treatment. Hippocrates himself applied it to open wounds. But its use as a cure for contagion fell by the wayside with the discovery of penicillin, and the source of its bug-blasting abilities remained a mystery. Until now.

Researchers treated E. coli bacteria with small amounts of silver. They found that the metal messes with the bugs’ proteins, wreaking havoc on their metabolism. It also generates reactive chemicals that attack the microbes from within. All this weakens the bacteria’s defenses, which allows other, more conventional antibiotics to slip in and do their work. Even killing microbes that were formerly antibiotic resistant.

Mice with fatal infections were also saved with a silver and antibiotic combo, and at doses that did the sick rodents no harm. This silver was delivered by injection. For werewolves, the preferred silver delivery system is still the bullet.

—Karen Hopkin