EFFICACY OF USING AN ALLOCHTONOUS PROBIOTIC BACTERIUM Escherichia coli Nissle (1917) ON GROWTH AND IMMUNE RESPONSE OF NILE TILAPIA

Probiotics are used  in  aquaculture  as health and growth promoters as well as for prophylaxis.  Escherichia coli Nissle 1917 (EcN ) is a human probiotic known to outcompete intestinal pathogens and strengthen the tight junctions of the intestinal barrier in mammals.  To date, we were not able to find literature that discusses the use of human probiotics as piscine probiotics. We assessed the possible benefits of using EcN as a probiotic for tilapia. EcN was added to the diet of the fish at various concentrations and offered to them for 8 weeks. Survival, growth, condition index and hematological parameters  were evaluated . A lso  fish  were  challenged with  Aeromonas hydrophila and Edwardsiella tarda . Results showed that EcN doesn't have a significant effect on survival and growth of Nile tilapia Oreochromis niloticus . Hematological parameters suggest an effect on the immune system of the fish offered EcN  and but there was no difference in survival between probiotic offered fish and controls with regards to pathogen challenged individuals. It seems the immune response was to the EcN itself.