Effects of Bacteria Bacillus thuringiensis (Bt) on the Digestive System of the Land Snail Eobania vermiculata

摘要

The present work was investigated to evaluate the effect of two concentrations of bacterial suspension (Bacillus thuringiensis) on the land snail Eobania vermiculata. The selected concentrations were 1 × 10~8 and 3 × 10~8. Samples from the esophagus, stomach, intestine and digestive gland were examined under light microscope. Esophagus of snails treated with 1× 10~8 concentration exhibited no effect. While, 3×10~8 bacterial suspension disorganized the esophageal epithelia cells. The stomach of snails treated with both concentrations showed marked histological alterations including more flattened folds of the mucosa and destruction of some of its epithelial cells. Also, the intestine of snails treated with both concentrations exhibited great alteration in the epithelial and glandular cells. The lumen of the digestive tubules in the digestive gland of the treated snails became wider containing many cell fragments. Many inclusions inside large vacuoles were detected in the epithelial cells of the digestive tubules of the treated snails. The present study showed the moullscsidal effect of Bacillus thuringiensis on the land snails Eobania vermiculata.