Autochthonous vs allochthonous probiotic strains to Rhamdia quelen.

The aim of this study was to obtain an autochthonous probiotic candidate strain from the silver catfish (Rhamdia quelen) intestinal tract, comparing its in vivo performance with an allochthonous probiotic isolated from another fish, Nile tilapia (Oreochromis niloticus), in a growth performance assay. The study was divided in two parts: in vitro and in vivo assay followed by challenge with A. hydrophila.