title: Helicobacter pylori cagA 12-bp insertion can be a marker for duodenal ulcer in Okinawa, Japan.
abstract: OBJECTIVE
  Helicobacter pylori cagA can be classified into mainly two types (East-Asian-type and Western-type cagA) according to the repeat regions located in the 3' region. Recent studies showed that the Western-type cagA in strains from Okinawa, Japan formed a different cluster (J-Western-type cagA subtype). It has also been reported that J-Western-type cagA possesses a 12-bp insertion located in the 5' region of cagA sequence.
  
  
  METHODS
  The prevalence of 12-bp insertion in cagA in Okinawa and the United States (U.S.) was examined by DNA sequencing. The primer pair that can detect the 12-bp insertion only by polymerase chain reaction was then designed. The prevalence of strains with 12-bp insertion was examined in 336 strains isolated from Okinawa by polymerase chain reaction.
  
  
  RESULTS
  In case of Western-type cagA/vacA s1m2 strains, the prevalence of 12-bp insertion was significantly higher in strains isolated from Okinawa than that from the U.S. (P = 0.002). Phylogenetic tree showed that strains with 12-bp insertion formed two individual clusters within J-Western-type cagA subtype; one is from Okinawa and another is from the U.S. The designed primer set showed high sensitivity (100%) and specificity (90.8%) in Okinawa. The 12-bp insertion was found in 23.7%, 14.3%, 4.2%, and 4.0% of strains with duodenal ulcer (DU), gastritis, gastric cancer, and gastric ulcer (GU), respectively (P < 0.001 for DU vs GU) in Okinawa.
  
  
  CONCLUSIONS
  Although the mechanisms are unknown, the presence of 12-bp insertion was associated with the presence of DU and might have a suppressive action on GU and gastric cancer.
authors.affiliation: Departments of Environmental and Preventive Medicine, Oita University, Yufu-City, Oita, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Seiji
authors.initials: S
authors.lastname: Shiota
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsunari
authors.forename: Rumiko
authors.initials: R
authors.lastname: Suzuki
authors.forename: Masahide
authors.initials: M
authors.lastname: Watada
authors.forename: Tran Thanh
authors.initials: TT
authors.lastname: Binh
authors.forename: Nagisa
authors.initials: N
authors.lastname: Kinjo
authors.forename: Fukunori
authors.initials: F
authors.lastname: Kinjo
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001706:Biopsy; D016009:Chi-Square Distribution; D004252:DNA Mutational Analysis; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis*; D004381:Duodenal Ulcer / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D005756:Gastritis / Q000175:diagnosis / Q000382:microbiology; D005819:Genetic Markers; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016254:Mutagenesis, Insertional; D016017:Odds Ratio; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000382:microbiology; D013276:Stomach Ulcer / Q000175:diagnosis / Q000382:microbiology; D014481:United States / Q000453:epidemiology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D005819:Genetic Markers; C080866:cagA protein, Helicobacter pylori