Due to the high costs of performing an infection challenge in fish (in vivo), we developed an ex vivo assay to evaluate the effect of dietary selenium on fish cells in response to infections with P. salmonis. By doing so, we characterized the infection phenotype of P. salmonis infecting SHK-1 cells grown in non-supplemented (FBS) or supplemented cell culture media with 2% of SSP1 and SSP5. Here, SENP6 is linked to infection.