γ-Glutamyltransferase Is a Helicobacter pylori Virulence Factor but Is Not Essential for Colonization

The contribution of glutamyl transpeptidase (GGT) (γ-glutamyltransferase [EC 2. 3. 2. 2]) to Helicobacter pylori virulence was investigated in piglets and mice using GGT-deficient isogenic strains. All animals became colonized. However, the bacterial load was significantly lower for mutant bacteria than for parent strains. These results suggest that GGT activity provides an advantage to H. pylori in colonization.