title: Molecular Epidemiology of Helicobacter pylori Infection in Nepal: Specific Ancestor Root.
abstract: Prevalence of Helicobacter pylori infection in Nepal, a low-risk country for gastric cancer, is debatable. To our knowledge, no studies have examined H. pylori virulence factors in Nepal. We determined the prevalence of H. pylori infection by using three different tests, and the genotypes of virulence factors were determined by PCR followed by sequencing. Multilocus sequence typing was used to analyze the population structure of the Nepalese strains. The prevalence of H. pylori infection in dyspeptic patients was 38.4% (56/146), and was significantly related with source of drinking water. In total, 51 strains were isolated and all were cagA-positive. Western-type-cagA (94.1%), cagA pre-EPIYA type with no deletion (92.2%), vacA s1a (74.5%), and m1c (54.9%) were the predominant genotypes. Antral mucosal atrophy levels were significantly higher in patients infected with vacA s1 than in those infected with s2 genotypes (P = 0.03). Several Nepalese strains were H. pylori recombinants with genetic features of South Asian and East Asian genotypes. These included all East-Asian-type-cagA strains, with significantly lesser activity and inflammation in the corpus than the strains of the specific South Asian genotype (P = 0.03 and P = 0.005, respectively). Although the population structure confirmed that most Nepalese strains belonged to the hpAsia2 population, some strains shared hpEurope- and Nepalese-specific components. Nepalese patients infected with strains belonging to hpEurope showed higher inflammation in the antrum than strains from the Nepalese specific population (P = 0.05). These results support that ancestor roots of Kathmandu`s people not only connected with India alone.
authors.affiliation: Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Hasama-machi, Yufu-City, Oita, Japan; Gastroentero-Hepatology Division, Department of Internal Medicine, Airlangga University Faculty of Medicine, Surabaya, Indonesia; Institute of Tropical Disease, Airlangga University, Surabaya, Indonesia.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Miftahussurur
authors.affiliation: Gastroenterology Department, Maharajgunj Medical Campus, Tribhuvan University Teaching Hospital, Kathmandu, Nepal.
authors.forename: Rabi Prakash
authors.initials: RP
authors.lastname: Sharma
authors.affiliation: Gastroenterology Department, Maharajgunj Medical Campus, Tribhuvan University Teaching Hospital, Kathmandu, Nepal.
authors.forename: Pradeep Krishna
authors.initials: PK
authors.lastname: Shrestha
authors.affiliation: Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Hasama-machi, Yufu-City, Oita, Japan.
authors.forename: Rumiko
authors.initials: R
authors.lastname: Suzuki
authors.affiliation: Department of Molecular Pathology, Faculty of Medicine, Oita University, Hasama-machi, Yufu-City, Oita, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Uchida
authors.affiliation: Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Hasama-machi, Yufu-City, Oita, Japan; Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009390:Nepal / Q000453:epidemiology; D015995:Prevalence; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
chemical_list: D037521:Virulence Factors