title: Determination of mutations of the 23S rRNA gene of Helicobacter pylori by allele specific primer-polymerase chain reaction method.
abstract: OBJECTIVE
  Susceptibility to clarithromycin of Helicobacter pylori (H. pylori) is caused by single nucleotide polymorphisms (SNPs) of the 23SrRNA gene. Allele specific primer-polymerase chain reaction (ASP-PCR) is one of the methods for determining SNPs, which can measure SNPs easily within a short period by PCR amplification alone without digestion with restriction enzymes. The aim of the present study was to develop the ASP-PCR assay for determining SNPs at positions 2,142 and 2,143 of the 23S rRNA gene of H. pylori.
  
  
  METHODS
  In total, 112 patients with H. pylori infection based on positive results of a rapid urease test (RUT) were enrolled in the study. Thirty-five had failed to eradicate H. pylori by a clarithromycin-based regimen. DNA was extracted from the RUT-positive gastric tissue samples. SNPs from adenine to guanine at positions 2,142 and 2,143 of the 23S rRNA of H. pylori (A2,142G and A2,143G) were determined by the ASP-PCR method. Minimum inhibitory concentrations (MICs) of clarithromycin for H. pylori were also measured.
  
  
  RESULTS
  Forty-nine of 112 patients were infected with wild-type strains of H. pylori. Thirty-nine patients were infected with strains with A2,143G mutations. Twenty-three patients were infected with both wild-type strains and those with A2,143G mutations. Only one patient was infected with the strain with A2,142G mutation. H. pylori strains with A2,143G or A2,142G mutation had significantly higher MICs for clarithromycin.
  
  
  CONCLUSIONS
  The ASP-PCR assay for 23S rRNA mutation of H. pylori is a useful method to detect clarithromycin-resistant strains of H. pylori easily.
authors.affiliation: First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Nakamura
authors.forename: Takahisa
authors.initials: T
authors.lastname: Furuta
authors.forename: Naohito
authors.initials: N
authors.lastname: Shirai
authors.forename: Mitsushige
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kajimura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Soya
authors.forename: Akira
authors.initials: A
authors.lastname: Hishida
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004381:Duodenal Ulcer / Q000382:microbiology; D005260:Female; D005756:Gastritis / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D013276:Stomach Ulcer / Q000382:microbiology
chemical_list: D012338:RNA, Ribosomal, 23S