Experimental Evolution of Silver Resistance in Escherichia coli. Escherichia coli str. K-12 substr. MG1655

Silver is highly toxic to bacteria in both ionic and nanoparticle forms. Silver impacts many aspects of bacterial physiology, and so it has been postulated that resistance to it will be difficult to evolve. However, silver resistance has occasionally been reported in nature, and we previously showed the rapid evolution of resistance to silver nanoparticles (AgNP) in Escherichia coli. The results of the present study further indicate that even highly sensitive bacteria can rapidly evolve resistance to ionic silver, suggesting caution with respect to the idea that silver presents a difficult challenge for bacteria to overcome.