Silver turns bacteria into deadly zombies

[Skyfarmr]

This article describes the action of silver nitrate on a species of bacteria; not sure if colloidal silver has this type of action on bacteria. Anyone who has used Colloidal Silver for an infection would most likely say yes.

http://news.sciencemag.org/biology/2015/05/silver-turns-bacteria-deadly-zombies?utm_source=facebook&utm_medium=social&utm_campaign=facebook

By Emily Conover 1 May 2015 3:45 pm 30 Comments
The zombie apocalypse may be more than just a horror story for some bacteria. New research shows that when exposed to a microbe-slaying silver solution, the germs can “go zombie,” wiping out their living compatriots even after death. The results may explain silver's long-lasting antibacterial power and could improve the performance of medical products that keep us safe from harmful pathogens.

The use of silver in medicine dates back thousands of years, and scientists have long known that the metal is a potent antibacterial agent. Silver ions perform their deadly work by punching holes in bacterial membranes and wreaking havoc once inside. They bind to essential cell components like DNA, preventing the bacteria from performing even their most basic functions.

But silver's "zombie effect" has gone unrecognized—until now. To uncover this grisly mechanism, scientists first killed a sample of the bacterium Pseudomonas aeruginosa using a solution of silver nitrate. Then, they carefully separated the dead bacteria from the silver solution. When they exposed living bacteria to the dead, they witnessed a microscopic massacre: Up to 99.99% of the living bacteria met their doom.

Using electron microscopy, the researchers imaged the dead bacteria and discovered what caused them to go on their killing spree. Reservoirs of silver nanoparticles had built up in their corpses, indicating that the dead bacteria act like sponges, soaking up silver as they die. The stored silver can leach out to the environment, "especially if the environment contains other sponges for that silver," says chemist David Avnir of the Hebrew University of Jerusalem, the senior author of the new study. "In our case, the other sponge is a living bacterium."

The researchers, who published their findings last week in Scientific Reports, also looked at the killing power of the solution they separated from the zombie bacteria. When they started with low concentrations of silver nitrate, the leftover solution wasn’t strong enough to completely wipe out the second round of bacteria. This indicates the bacteria are actually removing silver from the solution, researchers say. When they started out with high concentrations of silver nitrate, the solution retained its killing power through both groups of bacteria, presumably because the first round of bacteria hadn't been able to soak up all of the silver.

“This is an important aspect of [silver] that I’ve not seen anyone talk about before,” says molecular microbiologist Simon Silver of University of Illinois, Chicago, who was not involved in the research. "This paper is a new spin on it, to me, and I think rather a good one."

Silver nitrate is also used topically, not internally, as far as I know. A high quality Colloidal silver (which is ideally a solution of silver nanoparticles), on the other hand, can be safely taken internally and used topically, as well, without concern for the caustic properties of Silver nitrate.
Too bad they didn't try this study with colloidal silver instead.

The original report with a description of the scientific method can be viewed in more depth here:
http://www.nature.com/srep/2015/150330/srep09555/full/srep09555.html