Research Article: Investigating the effect of water filter made using polyurethane foam containing silver nanoparticles on controlling Yersinia ruckeri in Oncorhynchus

The aim of this study was to evaluate the efficiency of polyurethane foam containing silver nanoparticles synthesized by Verbena officinalis leaf extract in controlling of Yersinia ruckeri in treatment of water tanks of rainbow trout farming. Biosynthesis of silver nanoparticles is done with ۲mM silver nitrate solution and Verbena officinalis extract. To study antibacterial effects of the produced foams in vitro methods were used, including antibiogram tests on a petri dish, the diameter of inhibition and tube test at different times. Also In vivo methods were used consisting of treatment of water contaminated with bacteria in the presence and absence of fish. Results of mean of diameter of inhibition zone of foam containing ۵۰ and ۱۰۰mg of Ag-NPs on Yersinia ruckeri were ۱۵.۳۳±۱.۶ and ۱۴.۸۳ ±۰.۷۶mm respectively. Yersinia ruckeri was completely removed after ۲h contact with foams of ۵۰ and ۱۰۰ mg Ag-NPs in water treatment without fish, and after ۱۰min in test tubes at different times. Antibiogram tests showed no colonies in ۵۰ and ۱۰۰mg Ag-NPs at the bottom of the foam. Water treatment in the presence of fish showed a significant reduction in density of bacteria after ۴۸h contact with filters containing ۵۰ and ۱۰۰mg silver nanoparticles. Results of this study, as a new production of nano-biofilter, can be used to reduce and control Yersinia ruckeri bacteria in rainbow trout fish farms.