title: cag pathogenicity island of Helicobacter pylori in Korean children.
abstract: BACKGROUND
  cag pathogenicity island is reported to be a major virulence factor of Helicobacter pylori. The aim of this study was to investigate the status of cag pathogenicity island genes and gastric histology in Korean children with H. pylori gastritis.
  
  
  METHODS
  Helicobacter pylori DNA was extracted from antral biopsy specimens from 25 children with H. pylori gastritis. Specific polymerase chain reaction assays were used for four genes of cag pathogenicity island. The features of gastritis were scored in accordance with the updated Sydney System.
  
  
  RESULTS
  cagA was present in 23 (92%) of 25 children, and cagE in 24 (96%). Twenty-two (88%) children were cagT positive and 19 (76%) virD4 positive. All of the selected genes of the cag pathogenicity island were present in 17 (68%) children and completely deleted in one child. There were no differences in neutrophil activity and chronic inflammation between children infected with intact cag pathogenicity island strains and those with partially or totally deleted-cag pathogenicity island strains.
  
  
  CONCLUSIONS
  cag pathogenicity island is not a uniform, conserved entity in Korea. Completeness of cag pathogenicity island may not be the major factor to determine the severity of H. pylori gastritis in children.
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Chongno-gu, Seoul, Korea.
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Ko
authors.forename: Jeong Kee
authors.initials: JK
authors.lastname: Seo
mesh_terms: D000293:Adolescent; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005756:Gastritis / Q000382:microbiology / Q000473:pathology* / Q000503:physiopathology*; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology / Q000503:physiopathology; D016480:Helicobacter pylori / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D007723:Korea; D008297:Male; D016133:Polymerase Chain Reaction; D012720:Severity of Illness Index; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C080866:cagA protein, Helicobacter pylori