title: The Helicobacter pylori resistance rate to clarithromycin in Iran.
abstract: BACKGROUND
  Clarithromycin is the most commonly suggested antibiotic in Helicobacter pylori eradication regimens. Increasing antibiotic resistance rate to clarithromycin is the main reason for therapeutic failure. The resistance is associated with mutations in the 23S rRNA gene.
  
  
  OBJECTIVE
  The purpose of this study was to determine the clarithromycin resistance rate of isolated H. pylori strains from referral patients in Kashan, Iran.
  
  
  METHODS
  In total 95 H. pylori strains isolated from gastric mucosa of 246 patients with different clinical signs underwent gastroscopy in Kashan, Iran in 2013. The Epsilometer test was used to determine the minimum inhibitory concentrations (MICs) of clarithromycin (CLR) in isolated H. pylori strains. Occurrence of mutation in 23S rRNA gene of clarithromycin-resistant strains was investigated with polymerase chain reaction-sequencing method.
  
  
  RESULTS
  Antibiotic susceptibility pattern showed that 32 strains (33.7%) were resistant to clarithromycin (MICs ≥1 μg/ml), 33.7% were intermediate resistant, while 31 of H. pylori strains (32.6%) were susceptible. The 23S rRNA gene mutations at positions A2143G and A2142G were detected in H. pylori clarithromycin-resistant strains.
  
  
  CONCLUSIONS
  The resistance rate to clarithromycin in Iran is high. H. pylori clarithromycin-resistant strains were not associated with sex, age, and disease. The A2143G mutation in clarithromycin-resistant H. pylori strains was the predominant finding.
authors.affiliation: 1 Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences , Kashan, Iran .
authors.forename: Shahrbanoo
authors.initials: S
authors.lastname: Keshavarz Azizi Raftar
authors.forename: Rezvan
authors.initials: R
authors.lastname: Moniri
authors.forename: Mahmood
authors.initials: M
authors.lastname: Saffari
authors.forename: Mohsen
authors.initials: M
authors.lastname: Razavi Zadeh
authors.forename: Abbas
authors.initials: A
authors.lastname: Arj
authors.forename: Seyed Gholam Abbas
authors.initials: SG
authors.lastname: Mousavi
authors.forename: Hamed
authors.initials: H
authors.lastname: Mirzaei Ghazi Kalayeh
authors.forename: Kamran
authors.initials: K
authors.lastname: Dastehgoli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D017291:Clarithromycin / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D005260:Female; D005756:Gastritis / Q000453:epidemiology / Q000382:microbiology; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D007492:Iran; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010437:Peptic Ulcer / Q000453:epidemiology / Q000382:microbiology; D017354:Point Mutation; D012329:RNA, Bacterial / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D017291:Clarithromycin