title: Vacuolating toxin gene polymorphism among Helicobacter pylori clinical isolates and its association with m1, m2, or chimeric vacA middle types.
abstract: BACKGROUND
  Helicobacter pylori vacuolating cytotoxin encoded by vacA plays an essential role in H. pylori-related pathogenesis. Specific vacA alleles are believed to be associated with increased virulence. Association among vacA polymorphism, vacA middle genotypes, and various H. pylori-related diseases was thus investigated.
  
  
  METHODS
  Eighty-nine isolates from patients with various gastrointestinal diseases were examined for restriction fragment length polymorphism (RFLP) of the 2.0-kb polymerase chain reaction-amplified vacA middle region. Further genetic heterogeneity was assessed with ureA-ureB RFLP.
  
  
  RESULTS
  Twenty-eight distinct vacA RFLPs were seen among 89 isolates. Each pattern was associated with one specific vacA middle genotype. The association of specific RFLPs with certain clinical manifestations was noted among six common groups. Further RFLP analysis of the 2.4-kb ureA-ureB segment from isolates in four popular vacA RFLPs showed high genetic variation.
  
  
  CONCLUSIONS
  The vacA genetic polymorphism may be associated with different gastrointestinal diseases.
authors.affiliation: Dept. of Life Science, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: J C
authors.initials: JC
authors.lastname: Yang
authors.forename: C H
authors.initials: CH
authors.lastname: Kuo
authors.forename: H J
authors.initials: HJ
authors.lastname: Wang
authors.forename: T C
authors.initials: TC
authors.lastname: Wang
authors.forename: C S
authors.initials: CS
authors.lastname: Chang
authors.forename: W C
authors.initials: WC
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D003603:Cytotoxins / Q000235:genetics*; D005260:Female; D005767:Gastrointestinal Diseases / Q000382:microbiology; D014644:Genetic Variation; D005838:Genotype; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D001426:Bacterial Proteins; D003603:Cytotoxins; C074689:VacA protein, Helicobacter pylori