Infected groups fed with low and medium enriched diets had lower number of bacteria (3.1 x104 and 1.4 x 104) in the posterior intestines on week 16, but the concentration was higher (9.6 x 106) in group fed with high enriched diet. Gill, skin, and gastrointestinal tract have been demonstrated to be the portal of entry for many microbial pathogens [28].