Table 1.

Virulence factors of Helicobacter pylori[4-7]

Virulence factor	Function
H. pylori colonization
Urease	Buffers stomach acid, toxic effect on epithelium cells, disrupting cell tight junctions, and sheathing antigen
Flagella	Active movements through mucin
BabA	Adhesin
H. pylori survival
Nox1	Resistance to killing by phagocytes, infected-site inflammation
Superoxide dismutase	Resistance to killing by phagocytes
Catalase	Resistance to killing by phagocytes
Phospholipase A	Digest phospholipids in cell membranes
Alcohol dehydrogenase	Gastric mucosal injury
Tissue inflammation and damage
Vac A	Cytotoxicity
cag PAI	31 genes coding for type IV secretion system
CagA	Immunodominant antigen (part of cag PAI)
OipA	Induce inflammation, especially for IL-8
DupA	Induce inflammation via CagA, OipA and/or VacA
HP-NAP	Neutrophil activation
Lewis x and y antigens	Molecular mimicry, autoimmunity
LPS	Low toxicity
Other
IceA	Homolog of type II restriction endonuclease

H. pylori: Helicobacter pylori; BabA: Blood-group-antigen-binding adhesion; CagA: Cytotoxin associated gene antigen; DupA: Duodenal ulcer promoting A; HP-NAP: H. pylori neutrophil activation protein; IceA: Induced by contact with epithelium factor antigen; LPS: Lipopolysaccharide; Nox1: NADPH oxidase 1; OipA: Outer inflammatory protein A; Vac A: Vacuolating cytotoxin A; IL: Interleukin.