Antibacterial silver nanoparticles: effects on bacterial nucleic acids

Various microorganisms are located on the human skin, mucous membrane and inside the human body. Many of these microorganisms are beneficial and few are even essential, however, some pathogens are known to cause infection and have the ability to attack and damage the host tissue. Treatment of infectious bacterial disease by antibiotics is one of the major conventional strategies. Gram-positive and Gram-negative bacteria have developed resistance to conventional antibiotics by various mechanisms, including overexpression of efflux pumps, preventing drug penetration into the cells, genetic mutations, increased production of competitive inhibitors of antibiotics, or overexpression of enzymes that inactivate or hydrolyze antibiotics. Consequently, finding a new approach to overcome these hindrances is vital for the treatment of severe bacterial infections. Nanomaterials can be effective therapeutic compounds, with unique properties compared to bulk materials. Metal and metal oxide nanoparticles, particularly silver nanoparticles, have demonstrated strong antibacterial activity against most (if not all) multidrug-resistant bacteria. Several antibacterial mechanisms have been proposed for these nanoparticles, however, their interaction with bacterial nucleic acids is not completely understood, so this review discusses recent advances in this area.