[Effects of S-layer proteins from lactobacillus against Salmonella typhimurium adhesion and invasion on Caco-2 cells].

OBJECTIVE

S-layer proteins of Lactobacillus acidophilus were extracted and purified, then the effect of Lactobacillus acidophilus and its S-layer proteins against the adhesion and invasion of salmonella typhimurium to caco-2 cells were investigated.

METHODS

S-layer proteins were purified by anion-exchange column {diethylaminoethyl (DEAE) DE52}, and the inhibition of Lactobacillus acidophilus and its S-layer proteins were studied against the adhesion and invasion of salmonella typhimurium on Caco-2 cells.

RESULTS

S-layer proteins exhibited strongly inhibitory effects of adhesive and invading properties of Salmonella typhimurium. In the adhesive experiments (competitive, exclusive and displacement), Salmonella typhimurium adhesion was reduced by S-layer proteins and the ability of adherence to Caco-2 cells were 1.17% +/- 5.97%, 8.71% +/- 1.36% and 10.56% +/- 0.92%, respectively (P < 0.01). The influence to inhibit the competitive adhesion of Salmonella typhimurium was optimal. Furthermore, the S-layer proteins showed a stronger effect than Lactobacillus acidophilus to inhibit Salmonella typhimurium adhesion on Caco-2 monolayers (P < 0.01). Moreover, invasion of Salmonella typhimurium to Caco-2 monolayers was inhibited by S-layer proteins.

CONCLUSION

S-layer proteins inhibited adherence and invasion of Salmonella typhimurium. The result can merit a highlight for preventive or probiotic therapy in human or animals with disease caused by Salmonella typhimurium.