Antibacterial activity of AgO- chitosan composite against aquaculture pathogenic bacteria (case study: Edwardsiella tarda)

Chitosan is one of the bio-degradable natural products which can be used in heavy metal composites forms in antimicrobial agents and treatment measures [1, 2]. In this study, antibacterial activity of AgO-chitosan composite was tested against aquaculture bacterial disease agent, Edwardsiella tarda. Ag ions were adsorbed into the chitosan structure and surface chelation to form Ag-loaded composite. The physicochemical properties of the composites were determined by FTIR analysis, FESEM images and EDX. Disk diffusion method indicated that prepared composite has antibacterial activity. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) of composites were determined at different times and antibacterial amounts. Antimicrobial activity assays indicated that prepared composite exhibited marked inhibitory activity against Edwardsiella tarda. The minimum inhibitory concentration (MIC) values were slightly lower than the MBC values for two composites at different time and concentrations. Results demonstrated that AgO-chitosan composites could inhibit the growth of tested bacteria. The antibacterial activity of AgO-chitosan composites provides the possibility of further clinical investigations leading to its application in aquaculture industry.