title: Evidence for ethnic tropism of Helicobacter pylori.
abstract: Helicobacter pylori infection in humans is linked to gastritis, gastric and duodenal ulcers, and gastric cancer. Peptic ulcer disease, as distinct from chronic asymptomatic infection, is strongly associated with expression of bacterial virulence markers, including a major antigen, CagA, and the vacuolating cytotoxin VacA. We have previously described significant differences in colonization rates, independent of socioeconomic status, among ethnic groups in New Zealand. To evaluate relative risks for peptic ulcer disease, we examined the frequency of two virulence markers in H. pylori strains infecting these ethnic groups. Although these markers occurred significantly more frequently in strains isolated from Polynesians than in strains from Europeans, this frequency was not reflected in the incidence of peptic ulcer disease in the two groups. DNA fingerprinting of the urease gene showed that Polynesians are more frequently infected by a group of strains which are genetically distinct from those affecting European New Zealanders. Our data suggest that separate bacterial lineages may have evolved in parallel with race-specific specialization.
authors.affiliation: Department of Microbiology and Genetics, Massey University, Palmerston North, New Zealand.
authors.forename: S
authors.initials: S
authors.lastname: Campbell
authors.forename: A
authors.initials: A
authors.lastname: Fraser
authors.forename: B
authors.initials: B
authors.lastname: Holliss
authors.forename: J
authors.initials: J
authors.lastname: Schmid
authors.forename: P W
authors.initials: PW
authors.lastname: O'Toole
mesh_terms: D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology; D016172:DNA Fingerprinting; D005006:Ethnicity; D016480:Helicobacter pylori / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D011114:Polynesia / Q000208:ethnology; D012689:Sequence Homology, Nucleic Acid; D014510:Urease / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001427:Bacterial Toxins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D014510:Urease