title: Helicobacter pylori seroprevalence in Amerindians from isolated locations.
abstract: Helicobacter pylori seems universally distributed in all human populations, with high prevalence in the third world. Because H. pylori is an ancestral indigenous microbe of the human stomach, we hypothesized that its prevalence in isolated Amerindians would be high. A serologic study was performed on 19 Guahibo-Piaroa and 17 Warao in Venezuela, using H. pylori whole cell (WC) and CagA antigens from US strains. For Guahibo-Piaroa Amerindians, CagA seropositivity was 95%, but WC seropositivity was only 74%. For Warao, both CagA and WC seropositive proportions were low (65% and 76%, respectively). Because all CagA-seropositive individuals carry H. pylori, the results suggest that there has been bacterial antigen divergence, probably caused by genetic drift/natural selection, on humans and their microbes in isolated human groups.
authors.affiliation: Venezuelan Institute of Scientific Research, IVIC, Caracas, Venezuela.
authors.forename: Monica
authors.initials: M
authors.lastname: Contreras
authors.forename: Flor H
authors.initials: FH
authors.lastname: Pujol
authors.forename: Guillermo I
authors.initials: GI
authors.lastname: Pérez-Pérez
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Marini
authors.forename: Fabian A
authors.initials: FA
authors.lastname: Michelangeli
authors.forename: Liliana
authors.initials: L
authors.lastname: Ponce
authors.forename: María G
authors.initials: MG
authors.lastname: Domínguez-Bello
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000032:analysis; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D014644:Genetic Variation; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007197:Indians, Central American / Q000706:statistics & numerical data*; D014687:Venezuela / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G