Toxicological Effects Induced by Silver Nanoparticles in Zebra Fish (Danio Rerio) and in the Bacteria Communities Living at Their Surface

Abstract

The antimicrobial activity of silver nanoparticles (AgNP) makes them useful in a wide range of products although their environmental impact is still uncertain. The main goal of this study was to evaluate short-term effects induced by AgNP on gills oxidative status and bacterial communities living at the skin mucus of zebrafish. Both the number of bacteria colony forming units and bacteria growth obtained from skin mucus were lower in all concentrations tested (25, 50 and 100 µg nAg/L). Besides, AgNP exposure caused a significant decrease in bacteria growth in zebrafish exposed to 100 µg nAg/L. AgNP accumulated in zebrafish gills at both highest concentrations tested, but this accumulation did not appear to result in oxidative stress. Overall the results indicated toxicological effects of AgNP on bacteria communities living at the zebrafish mucus surface. Although silver accumulation was verified in gills, no evidence of toxicity in terms of oxidative stress was found.