Evaluation of changes in the bacterial flora population of the grass carp (Ctenopharyngodon idella) intestine and skin under the influence of colloidal silver nanoparticles

Document Type : Research Paper


1 M.Sc. Student in Fisheries, Department of Aquaculture, Faculty of Natural Resources, Urmia University, Urmia, Iran.

2 Professor in Aquaculture Department, Faculty of Marine Sciences, Tarbiat Modares University, Noor, Iran.

3 Scientific Member in Ecology Institute of Caspian Sea, Sari, Iran.


The aim of this study was evaluated the effect of colloidal silver nanoparticles on changes of intestine and skin tissues microflora population. After determination of colloidal nanosilver lethal concentration on grass carp, the fish samples were exposed to concentrations of 0.125, 0.25 and 0.5 mg/L nanosilver for 14 days (triplicate). The zero concentration of nanosilver was used as control sample. Then total count, mesophilla, Enterobacteriaceae and lactic acid bacteria population in intestine and skin tissues of fish were determined. The results indicated that increasing concentrations of nanosilver reduces the measured microflora population significantly. So that decreasing in bacterial population of skin was higher compared to the intestinal tissue. Also, results showed the Enterobacteriaceae and lactic acid bacteria in skin and intestine tissues were lowest and showed highest damage, respectively. This study clearly demonstrated that the antibacterial properties of silver nanoparticles was varies depending on different bacterial groups. Therefore, regard to probiotics role of lactic acid bacteria in fish intestine, sensitivity and reduction of their population to nanosilver, the fish immune system may be affected.