Higher motility enhances bacterial density and inflammatory response in dyspeptic patients infected with Helicobacter...

Motility mediated by the flagella of Helicobacter pylori is important for the cells to move toward the gastric mucus in niches adjacent to the epithelium; then, H. pylori uses the adhesin SabA to interact with sialyl-Le(x) on inflammatory host cells for persistent infection. Here, we reveal the clinical association of bacterial motility, SabA expression, and pathological outcomes.

Ninety-six clinical isolates were screened for bacterial motility, and the expression of SabA of each isolate was confirmed by Western blotting. H. pylori-infected patients were assessed for their bacterial density, sialyl-Le(x) expression, inflammatory scores, and clinical diseases.

The mean diameter in the motility assay was 17 mm, and eight (8.3%) of the strains had impaired motility, with a diameter <5 mm. H. pylori density in cardia, the acute inflammatory score in the body locus, and the prevalence rate of gastric atrophy were increased in patients infected with higher-motility strains (p = .023, <.001, or <.001, respectively). The total inflammatory scores (both acute and chronic) and bacterial density dramatically increased in patients expressing the sialyl-Le(x) antigen and infected with higher-motility, SabA-positive H. pylori (p = .016, .01, or .005, respectively).

These results suggest that the higher motility of H. pylori enhances pathological outcomes, and the SabA-sialyl-Le(x) interaction has a synergistic effect on virulence of the higher-motility strains.