Biosynthesized silver nanoparticles: decoding their mechanism of action in S. aureus and E. coli.

MELISA DE LOS ANGELES QUINTEROS; VIVIANA CANO ARISTIZÁBAL; MARIA GABRIELA PARAJE; PAULINA L PÁEZ

Journal of Clinical Toxicology

Journal of Clinical Toxicology

Año: 2017 vol. 07

he generation of oxidative stress in bacteria by the presence of silver nanoparticles (AgNPs) is already widely known1,2. If the cell cannot respond to oxidative injury produced by increased species reactive oxygen (ROS),the oxidation of macromolecules such as proteins, lipids and DNA occurs, leading to the death of the bacterium3,4. In previous results (Quinteros et al. 5), we observed as biosynthesized AgNPs that had antibacterial activity, generated an increase of ROS and RNI in Staphylococcus aureus, Escherichia coli andPseudomonas aeruginosa, being responsible for their toxicity and bacterial death. According to the above, we set out to delve into the mechanism of action of AgNPs, by determining markers of oxidative stress, such as protein oxidation, lipids, DNA and changes in membrane potential in two reference strains S. aureus ATCC 29213 and E. coli ATCC 25922. We found that theincrease in the levels of ROS is associated with the oxidation of different macromolecules important