Figure 8.

Histopathological examination of immunized mice after a challenge with the α-toxin. No histopathological changes were observed in the heart, liver, spleen, kidneys, colon, and brain of mice in the normal control group (a). Histopathological changes after the challenge were noticed in the tissues of mice orally vaccinated with PBS (b) or pPG/L. casei 393 (c). In the commercial vaccine group (d), histopathological changes were observed in the liver, kidneys, and colon of the mice, particularly in the colon after the challenge, whereas little or no histopathological changes were observed in the tissues of mice orally immunized with pPG-α/L. casei 393 (e). Tissue sections were stained with hematoxylin and eosin and photographed at 40× magnification.