Histopathological study and intestinal mucous cell responses against in Nile tilapia administered with GG.

AIM

This study aimed to examine the intestinal histopathological lesions and mucous cell responses in the entire intestines of Nile tilapia administered with GG (LGG)-mixed feed, after challenge.

MATERIALS AND METHODS

Intestinal samples from fish fed with control normal diet or LGG-mixed feed (10 colony-forming unit [CFU]/g feed) with or without in phosphate-buffered saline challenge (7.46 × 10 CFU/mL/fish) were collected and processed for histopathological study. The mucous cell responses were evaluated using histochemistry, using Alcian blue (AB) at pH 2.5, AB at pH 1.0, and periodic acid-Schiff-AB at pH 2.5. The quantification of the intestinal mucous cell size and the staining character of each mucin type from the entire intestine were recorded and counted.

RESULTS

Histopathological study showed remarkable lesions only in the proximal intestine in fish infected with , while LGG-fed fish had less intestinal damage, perhaps resulting from heterophil infiltration. Furthermore, a significant (p<0.01) increase in mixed mucous cell numbers was observed mainly in the proximal intestine of all challenged fish, compared with normal diet-fed fish without challenge, and also in LGG-fed fish with challenge compared with LGG-fed fish without challenge.

CONCLUSION

Dietary LGG-fed Nile tilapia showed improvements in host innate immunity. In addition, LGG was effective in decreasing intestinal lesions from a-induced intestinal damage. Moreover, increasing numbers of mixed mucous cells in the proximal intestine might be indicative of certain pathological conditions in Nile tilapia after infection.