Abstract
Escherichia coli can rapidly evolve resistance to silver nanoparticles (AgNP). Here we utilize experimental evolution to demonstrate that selection for Ag+ resistance confers resistance to AgNPs. By generation 200, the minimum inhibitory concentration of Ag-selected increased by ~9.5-fold compared to control replicates. Ag-selected replicates also showed superior resistance to AgNPs. Genomic analysis identi ed candidate mutations in the silver-resistant lines including several in the gene cusS, which encodes a histidine kinase that senses copper and silver ions, as well as ompR, outer membrane protein R, and in the RNA polymerase subunits (rpoA, rpoB, rpoC). Molecular simulations of the common cusS mutations showed that they imputed greater silver ion af nity compared to that of the ancestral cusS sequence. This study supports the contention that the primary action of AgNPs against bacteria is the release of Ag+ ion. Furthermore it validates that bacterial resistance to silver can occur rapidly by simple genomic changes.
| Original language | English |
|---|---|
| Pages (from-to) | 1047 |
| Journal | JSM Nanotechnology & Nanomedicine |
| Volume | 5 |
| Issue number | 1 |
| State | Published - 2017 |