Immunohistochemistry of gill lamellae from un-infected and Y. ruckeri infected rainbow trout.

The sections are from (A) uninfected control, (B) 1 mpi, (C) 10 mpi, (D) 6 hpi, (E) 48 hpi and (F) 7 dpi and were stained with rabbit anti-Y. ruckeri polyclonal antibody and HRP conjugated goat anti-rabbit IgG antibody. The nuclei were counterstained with hematoxylin. Y. ruckeri was detected inside the gill lamellae already at 1 mpi and the blood capillaries in the gill lamellae at 7 dpi, indicating systemic infection.