The effect of silver ions and silver nanoparticles on Staphylococcus aureus

Bacterial infections can cause serious health issues in treatment of tumour diseases, as they are one of the leading causes of dead in the developed countries. Staphylococcus aureus belong to the bacterial strains causing major health issues. Moreover, this strain is well adaptable to the environment. It is not surprising that formation of antibiotics resistance and creation of multi-resistant strains was found. Therefore, looking for new approaches for eliminating of the bacterial threat is still topic. Advanced metal-based nanomaterials seem to have promising properties for this purpose. The aim of this study was to determine the antimicrobial effect of different concentrations of silver nanoparticles (200 nm) on grampositive bacteria S. aureus. Studying of the development of bacteria in the hostile conditions is also interesting from the point of view of very basic questions “what is live” and “are we alone”. Many bacteria have the property to adapt over time to an environment modified with heavy metals. Recently, potential changes in sugar phosphate skeleton of DNA were described and discussed due to the effect of arsenic. Primarily, we utilized Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry for basic characterization of bacterial strain of S. aureus. Then, we used two types of methods for determination of silver nanoparticles inhibition effect as (i) method based on the growth curves and (ii) measurements of inhibition zones. The applied silver nanoparticles also generated oxidative stress revealed by spectrophotometric assays. We confirmed that silver nanoparticles had considerable inhibition of the growth of S. aureus.