The elongation factor Tu from  Lactobacillus reuteri  inhibits the adhesion of  Helicobacter pylori to porcine gastric mucin

Abstract

 Helicobacter pylori is a Gram-negative spiral-shaped microaerophilic bacterium that infects more than half of the world's population. Probiotic treatment may inhibit H. pylori infection by competition with the pathogen for the same receptor site (s) on the host mucosal surface. We previously found that Lactobacillus reuteri JCM1081 cell surface-associated elongation factor Tu (EF-Tu) was characterized as a sulfated carbohydrate-binding protein and may mediate adhesion of H. pylori to the host gastrointestinal tract. Here, we evaluated the role of EF-Tu in inhibiting H. pylori adhesion, using recombinant EF-Tu protein (His-EF-Tu). The addition of His-EF-Tu showed concentration-dependent inhibitory effects on the adhesion of H. pylori strains to porcine gastric mucin (PGM)-coated wells. Similar inhibitory effects were observed in H. pylori clinical isolates. Interestingly, sulfatase-treated PGM reduced H. pylori adhesion, whereas His-EF-Tu barely affected H. pylori adhesion on sulfatase-treated PGM. The inhibitory rate was similar to that of pretreatment with the sulfated carbohydrate recognition antibody PGM34. Western blotting revealed that EF-Tu was present in cell surface fractions isolated from several Lactobacillus strains. Thus, EF-Tu could inhibit the adhesion of several H. pylori strains, and the inhibitory effect may be mediated through competition of EF-Tu and H. pylori ligands for the same adhesion sites.