Different studies have used various genotypes of H.
pylori for OMVs characterization, for example, cag PAI+
toxigenic (strain containing the complete pathogenicity
island) and cag PAI− nontoxigenic strains. OMVs purified
from cag PAI+ and cag PAI− increased the proliferation
of human gastric adenocarcinoma AGS cells at low doses
of OMVs, while at higher OMVs doses, a growth arrest,
increased toxicity, and IL-8 production were observed