There is a global lack of efficient environmentally friendly remedies for the containment of parasitic disease in kept or farmed fish. Current treatment relies on old and well proven agents such as formaldehyde, peracetic acid/hydrogen peroxide or similar. Formaldehyde is efficient but also potentially hazardous to plant workers, at times detrimental to the fish, and most often only allowed for use on authorities’ exemption.
Certain natural bacteria make so-called cyclic lipopeptides (CLPs), some of which disturb the proper function of the cellular membranes of particular unicellular organisms. One such CLP is Biokos, which was shown to be an efficient countermeasure against all free-living stages of the freshwater parasite Ichthyophthirius multifiilis (“freshwater white spot”) (Liu et al., 2015; Al-Jubury et al., 2018).
We and others have since demonstrated that Biokos works against most ciliate fish parasites (e.g., Cryptocaryon, Trichodina, Philasterides and Chilodonella sp.) as well as some other commercially important protozoan fish pathogens (see, e.g., Watanabe et al., 2023; Sueiro et al., 2022; Maciel et al., 2024). Interestingly, Biokos also kills many of the protozoans causing harmful algal blooms in coastal waters around the globe.
Sundew currently manufactures and sells Biokos in the ornamental fish sector and we are preparing for also entering the food aquaculture sector. Recent collaborative studies done with cultured Trichodina-infected Tilapia fingerlings in Uganda indicate a bright future for Biokos in that regard (Agoe et al.).
Agoe et al., manuscript in preparation.
Al-Jubury et al., 2018. J. Fish Dis. 41:1147.
Liu et al., 2015. PLOS One 10:e0136241.
Maciel et al., 2024. Braz. J. Vet. Parasitol., in press.
Sueiro et al., 2022. Pathogens 11:267.
Watanabe et al., 2023. J. Fish Dis. 46:1311.