title: Mutations affecting domain V of the 23S rRNA gene in Helicobacter pylori from Cairo, Egypt.
abstract: BACKGROUND
  Clarithromycin is a main component of the recommended first-line triple therapy for Helicobacter pylori in Egypt. We aimed in our study to investigate the prevalence of clarithromycin-resistant H. pylori strains due to the point mutations at domain V of the H. pylori 23S rRNA among the Egyptian population using the polymerase chain reaction/restricted fragment length polymorphism (PCR/RFLP) assay.
  
  
  METHODS
  Gastric biopsies obtained from 100 dyspeptic patients who consecutively attended at Cairo University Hospital during the period from January to November 2013 were subjected to PCR/RFLP in order to detect the point mutations at domain V of the H. pylori 23S rRNA associated with clarithromycin resistance. The PCR amplicon of the 23S H. pylori rRNA is restricted with MboII for detection of A2142G mutation and with BsaI for A2143G mutation.
  
  
  RESULTS
  The prevalence of H. pylori infection among 100 patients was 70%; clarithromycin resistance was detected in 39/70 (57.7%) of positive H. pylori isolates. Occurrence of 23S rRNA A2142G mutations resulted in two DNA fragments (418 and 350 bp) by PCR-RFLP; on the other hand, no A2143G mutations were detected.
  
  
  CONCLUSIONS
  The high prevalence of clarithromycin resistance (57.7%) caused by A2142G mutations at domain V of the H. pylori 23S rRNA may mandate changing of the standard clarithromycin-containing triple therapy. The PCR/RFLP assay was a rapid and accurate method for molecular detection of H. pylori infection in addition to determination of different nucleotide mutations causing clarithromycin resistance.
authors.affiliation: a Clinical and Chemical Pathology Department, Faculty of Medicine , Cairo University , Egypt.
authors.forename: Doaa
authors.initials: D
authors.lastname: Ghaith
authors.affiliation: b Endemic Medicine and Hepatology Department, Faculty of Medicine , Cairo University , Egypt.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Elzahry
authors.affiliation: b Endemic Medicine and Hepatology Department, Faculty of Medicine , Cairo University , Egypt.
authors.forename: Gehan
authors.initials: G
authors.lastname: Mostafa
authors.affiliation: c Clinical and Chemical Pathology Department, Faculty of Medicine , Beni-Suef University , Egypt.
authors.forename: Sally
authors.initials: S
authors.lastname: Mostafa
authors.affiliation: a Clinical and Chemical Pathology Department, Faculty of Medicine , Cairo University , Egypt.
authors.forename: Rasha
authors.initials: R
authors.lastname: Elsherif
authors.affiliation: b Endemic Medicine and Hepatology Department, Faculty of Medicine , Cairo University , Egypt.
authors.forename: Iman
authors.initials: I
authors.lastname: Ramzy
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001706:Biopsy; D017291:Clarithromycin / Q000494:pharmacology; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004534:Egypt / Q000453:epidemiology; D005260:Female; D020459:Genes, rRNA / Q000235:genetics; D016481:Helicobacter Infections / Q000453:epidemiology / Q000235:genetics*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D012338:RNA, Ribosomal, 23S; D017291:Clarithromycin
keywords: 23S rRNA; Clarithromycin resistance; Helicobacter pylori; RFLP-PCR