title: Rare Helicobacter pylori Virulence Genotypes in Bhutan.
abstract: Both the prevalence of Helicobacter pylori infection and the incidence of gastric cancer are high in Bhutan. The high incidence of atrophic gastritis and gastric cancer suggest the phylogeographic origin of an infection with a more virulent strain of H. pylori. More than 90% of Bhutanese strains possessed the highly virulent East Asian-type CagA and all strains had the most virulent type of vacA (s1 type). More than half also had multiple repeats in East Asian-type CagA, which are rare in other countries and are reported characteristictly found in assciation with atrophic gastritis and gastric cancer consistent with Bhutanese strains having multiple H. pylori virulence factors associated with an increase in gastric cancer risk. Phylogeographic analyses showed that most Bhutanese strains belonged to the East Asian population type with some strains (17.5%) sharing East Asian and Amerindian components. Only 9.5% belonged to the European type consistant with H. pylori in Bhutan representing an intermediate evolutionary stage between H. pylori from European and East Asian countries.
authors.affiliation: Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsunari
authors.affiliation: Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan.|Gastroentero-Hepatology Division, Department of Internal Medicine, Faculty of Medicine-Institute of Tropical Disease, Airlangga University, Surabaya, Indonesia.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Miftahussurur
authors.affiliation: Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Shiota
authors.affiliation: Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Rumiko
authors.initials: R
authors.lastname: Suzuki
authors.affiliation: Gastroenterology Unit, Department of Medicine, Thammasat University Hospital, Pathumthani, Thailand.
authors.forename: Ratha-Korn
authors.initials: RK
authors.lastname: Vilaichone
authors.affiliation: Department of Molecular Pathology, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Uchida
authors.affiliation: Department of Surgery, Rajavithi Hospital, Bangkok, Thailand.
authors.forename: Thawee
authors.initials: T
authors.lastname: Ratanachu-ek
authors.affiliation: Department of Surgery, Jigme Dorji Wangchuck National Referral Hospital, Thimphu, Bhutan.
authors.forename: Lotay
authors.initials: L
authors.lastname: Tshering
authors.affiliation: GI and Liver Center, Bangkok Medical Center, Bangkok, Thailand.
authors.forename: Varocha
authors.initials: V
authors.lastname: Mahachai
authors.affiliation: Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan.|Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001631:Bhutan; D005260:Female; D005838:Genotype; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014774:Virulence; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori