Assessment of anti-fungal effect of Huwa-San TR-50 and determination of MIC and MLC on Saprolegnia sp. invitro and introduced as malachite green alternative

Saprolegnia sp. is the most important pathogenic fungi in fish. Saprolegnia parasitica, S. diclina, S. ferax and S. hypogina are the most abundance of the fungi that caused saprolegniasis in fish and hatcheries. They have global distributions and their presences were reported from fresh water fish farms of the world. Up till 2002, Saprolegnia infections in aquaculture were kept under control with malachite green. However, the use of malachite green has been banned worldwide due to its carcinogenic and toxicological effects and this has resulted in a dramatic re-emergence of Saprolegnia infections in aquaculture. Many investigations have been carried out on the introduction of an appropriate anti-fungal agent alternative to malachite green. Huwa- San TR- 50 is a disinfectant based on hydrogen peroxide. One liter of Huwa-San TR-50 contains 570 g hydrogen peroxide and 0.36 g silver as stabilizer. In this study, the antifungal effects, minimum lethal concentration (MLC) and minimum inhibitory concentration (MIC) of Huwa- San TR- 50 were conducted and compared to malachite green in vivo several doses including the 0, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 ppm on the isolates saprolegnia sp were isolated from Rainbow trout. The results of MIC and MLC levels on the saprolegnia sp isolate from rainbow trout eggs were 400 and 800 ppm respectively. The results suggest that Huwa- San TR- 50 could introduce as appropriate anti-fungal agent alternative to malachite green.