Post-infection by 3 h, IL-1β expression was significantly upsurged with E. tarda infection 2.78 and 4.42 fold-change in the head kidney of Nile tilapia received S. platensis at a dose of 5 g/kg fish feed and 10 g/kg fish feed, respectively, compared to infected control positive (+) and uninfected control negative (-) 1.12 and 0.3 fold-change, respectively. This evidence concerns the gene IL1B and infection.