Application of polyurethane foam containing silver zeolite (Zeomic) in water filtration system to control the infection caused by Streptococcus iniae in rainbow

Zeolites containing silver ion, in combination with synthetic fibers, show antibacterial activity. The purpose of this study was to use silver zeolite indirectly as antimicrobial agents to control Streptococcus iniae infection which recently has caused disease in some of rainbow trout farms in Iran. METHODES: In this context polyurethane foams containing silver zeolite (10 and 20%) were used in water filtration of semi circulation culture system of rainbow trout fry. After addition of Streptococcus iniae (105 Cell/ml) to water in culture systems, the filters were evaluated for efficacy in inhibiting bacteria through measuring bacterial loading in water, monitoring disease symptom and culture of bacteria from kidney and spleen. The results indicated that filters containing silver compounds could significantly reduce load of bacteria from the water to 102 (p<0.05) compared to the control. Filter with 10% silver zeolite had higher efficiency among others. According to the results of this study, it seems that silver zeolite in combination with polyurethane foams has the sufficient potential to control bacterial infection and disease prevention in semi circulation system of Rainbow trout. Development of these filters and their application in control of aquatic animal diseases can result in reduction of using chemical drugs.