During infection, the expression of IL-1β begins to decrease gradually, indicating that N. seriolae may inhibit the inflammatory response for survival by downregulating the expression of IL-1β, which is similar to that observed in Listeria (Meixenberger et al., 2010), Salmonella (Pie et al., 1996), and M. tuberculosis (Behar et al., 2011). This evidence concerns the gene IL1B and infection.