Objectives and hypothesis

Our objective is to reduce the need for antibiotics in marine larviculture by developing and combining two probiotic strategies (phages and bacteria). The use of combined therapies is inspired by human medicine and we will introduce such combinatory prophylactic therapies in aquaculture practice. Almost all treatments using one pathogen-antagonising principle will select for resistant pathogens. We hypothesise that by combining two biological approaches with very different targets, the risk of new resistance will be significantly reduced. We have available, and will continue to isolate, bacteriophages against larval pathogenic Vibrio. Also available are Vibrio-antagonistic Roseobacter. We will combine these probiotics in model challenge trials and pilot production trials to explore effects on larval survival, and monitor potential virulence and resistance properties using genomic analyses of the pathogens. We combine national and international expertise in a multidisciplinary project and the results will be directly applicable in aquaculture ensuring reduced losses and production of healthy fish and safe food. The project will provide knowledge and products for Danish engineering advisors in the aquaculture sector.