Title : Assessment of Using a Water Disinfectant to Inhibit Pathogenic Bacteria, Fungus and Harmful Algae in Aquaculture
Many common diseases and massive losses of shrimp and fish are due to bacteria, fungi and harmful algae. Overuse of antibiotics to treat diseases has been being prohibited because antibiotic resistant pathogens become a global issue. Another practice is to use alternative products in aquaculture to prevent disease outbreaks at optimal low doses. The theory of this work is to use a formulation of various components such as oxidizing agent (effective against pathogens and threats), essential organocatalyst (good for health and digestion), and inorganic acid (cleaning, denitrifying nitrite-rich environments) can reduce the amount and frequency of using antibiotics in intensive/semi-intensive aquaculture. This experimental design is to assess the efficacy of a water disinfectant Aqua-Protect against common aquatic animal diseases caused by bacterial pathogens (Edwardsiella ictaluri, Aeromonas hydrophila, Streptococcus iniae, Streptococcus agalactiae, Vibrio parahaemolitycus and Vibrio harveyi) and other threats (Saprolegnia fungus and Oscillatoria/Microcystis algae). The research also includes a toxicity assessment performed on tra catfish (5–7 g), tilapia (5–10 g) and whiteleg shrimp (~0.5 g). Broth dilution method (i.e. minimum inhibitory concentration MIC) was used in the inhibition tests against causative agents. The MIC was determined by the lowest concentration at which there was no visible bacterial/fungal growth (turbidity/plate count/microscopic observation of test solutions). For toxicity assessment on tra catfish, tilapia and whiteleg shrimp, the disinfectant product was applied at various concentrations in fresh/seawater. The collected data showed the effective inhibition against almost tested pathogenic organisms, and no harmful impacts on fish/shrimp at certain concentrations.