title: Prevalence of Helicobacter pylori in symptomatic patients and detection of clarithromycin resistance using melting curve analysis.
abstract: Abstract.
  
  
  BACKGROUND
  Clarithromycin is often a component of combination therapies for Helicobacter pylori eradication; however, increases in resistance rates have decreased the success of the treatment.
  
  
  OBJECTIVE
  This study was designed to determine the prevalence of H pylori infection in symptomatic patients and to detect clarithromycin resistance rates using melting curve analysis.
  
  
  METHODS
  Patients scheduled for upper endoscopy at the Endoscopy Unit of the Department of Gastroenterology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey, were assessed for enrollment in the study. Two pairs of gastric biopsy specimens (antrum and corpus) were obtained from each study patient. Histopathologic examination, rapid urease test, culture, and polymerase chain reaction (PCR) of the specimens were used to identify H pylori infection. Clarithromycin resistance was detected using melting curve analysis.
  
  
  RESULTS
  Seventy-five patients (41 women, 34 men; mean [SD]age, 42.6 [14.5] years [range, 17-70 years]) were included in the study. Using histopathology and rapid urease test, H pylori was detected in 40 (53.3%) of the 75 specimens. H pylori was detected using PCR in 40 (53.3%) specimens and by culture in 10 (13.3%) specimens. The specificity and sensitivity of PCR and culture were interpreted by comparing them with the results of histopathologic examination and urease tests. The specificity and sensitivity of PCR were 68.6% and 72.5%, respectively, and the specificity and sensitivity of culture were 97.1% and 22.5%, respectively. Of the 40 isolates, 21 (52.5%) were susceptible to clarithromycin, 12 (30.0%) were resistant, and a mixed susceptibility pattern was detected in 7 (17.5%) specimens. H pylori isolates from 19 (79.2%) of the 24 patients who had formerly used clarithromycin showed clarithromycin resistance.
  
  
  CONCLUSIONS
  The prevalence of H pylori infection was 53.3% for the symptomatic patients in this study, and 47.5% of the isolates showed clarithromycin resistance using melting curve analysis. The PCR-based system used in this study was accurate for the detection of H pylori infection as well as clarithromycin susceptibility testing directly in biopsy specimens.
authors.affiliation: Department of Microbiology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey.
authors.forename: Ayse Demet
authors.initials: AD
authors.lastname: Kaya
authors.affiliation: Department of Microbiology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey.
authors.forename: C Elif
authors.initials: CE
authors.lastname: Oztürk
authors.affiliation: Department of Gastroenterology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Akcan
authors.affiliation: Department of Microbiology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Behçet
authors.affiliation: Department of Microbiology, Ministry of Health, Ankara Training and Research Hospital, Ankara, Turkey.
authors.forename: A Esra
authors.initials: AE
authors.lastname: Karakoç
authors.affiliation: Department of Microbiology, Ministry of Health, Ankara Training and Research Hospital, Ankara, Turkey.
authors.forename: Mihriban
authors.initials: M
authors.lastname: Yücel
authors.affiliation: Metis Biotechnology Laboratory, Ankara, Turkey.
authors.forename: Müge
authors.initials: M
authors.lastname: Mısırlıoglu
authors.affiliation: Metis Biotechnology Laboratory, Ankara, Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Tuncer
keywords: Helicobacter pylori; PCR; clarithromycin resistance; melting curve analysis