Application of porous ceramic substrates containing silver nanoparticles in water filtration system to control the infection by Vibrio harveyi in white leg shrimp (Litopenaeus vannamei)

The purpose of this research was possibility evaluation of indirect use of Ag-NPs-coated porous ceramic in water filtration of culture system of shrimp post larvae to control Vibrio harveyi. After confidence of antibacterial activity of Ag-NPs-coated on porous ceramic against mentioned bacteria via in vitro experiments (Zone of inhibition test and Test tub test), porous ceramic filter media used for water treatment. Therefore, the performance of the Ag-NPs-coated on porous ceramics in removing pathogenic bacteria was studied in two phases: in the first phase, V. harveyi (1.5*108 cfu/ml) was inoculated to the water and efficacy of filters of inhibition of bacteria was evaluated via total count of bacteria in the test water; in the second phase, the performance of the Ag-NPs-coated on porous ceramic was tested in the presence of shrimp larvae and efficacy of filters in inhibition of bacteria was evaluated via total count of bacteria, mortality rate, clinical signs, and also hepatopancreas and muscle culture. Based on the results, the highest zone of inhibition obtained in presence of Ag-NPs-coated porous ceramic modified by an aminosilane coupling agent, 3-aminopropyltriethoxysilane (APTES) (The samples were immersed in the silver colloidal solution for 24 h).The results of flow test showed the highest bacteria removal efficiency from water with complete (100%) removal of the targeted pathogen in the flow rate of 1 L/min. In the second phase, the results indicated significant difference in decreasing of water bacteria, shrimp mortality and disease symptoms in treatment containing silver compounds compare to controls.