Researchers at the University of Jerusalem have found that Pseudomonas aeruginosa bacteria killed with silver nitrate can be used to kill living bacteria.
"It worked even better than our expectation. It's a new, previously unrecognized mechanism of how an antibacterial agent kills," researcher David Avner told Chemistry World.
© Photo : Racheli Ben-Knaz Wakshlak, Rami Pedahzur & David AvnirTEM (bright background) and STEM (dark background) of P. aeruginosa before (a and d) and after (b, c and e) treatment with silver; the black (b) and white (e) granules represent silver deposition which account for the zombies biocidal action.

TEM (bright background) and STEM (dark background) of P. aeruginosa before (a and d) and after (b, c and e) treatment with silver; the black (b) and white (e) granules represent silver deposition which account for the zombies biocidal action.
© Photo : Racheli Ben-Knaz Wakshlak, Rami Pedahzur & David Avnir
The scientists found that the silver absorbed by the cells are used as silver "reservoirs for further killing." However, the bacteria in the experiment are themselves dead, having been killed by the silver nitrate.
"The experiments here conclusively show that the bacteria are dead," Dr. Peter Chivers told Chemistry World.
The report on the experiments, published in the journal Nature, concludes that the effectiveness of the cells is due to the silver absorbed by them rather than the residue from dead cells. A control group of bacteria cells killed by heat did not lead to the same effect.