title: Prevalence of Primary Antimicrobial Resistance of H. pylori in Turkey: A Systematic Review.
abstract: BACKGROUND
  The prevalence of clarithromycin resistance has increased to the 20% or more in different regions of the world. Clarithromycin resistance is known to be responsible for most of the treatment failures in Helicobacter pylori (H. pylori) infection. The aim of this systematic review was to summarize the prevalence of primary antibiotic resistance (amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline) of H. pylori strains in different geographical regions of Turkey.
  
  
  METHODS
  An Internet search was performed using PubMed and the ULAKBIM Turkish Medical Database. The terms "primary antibiotic resistance (separately; amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline) of H. pylori" with and without "Turkey" or "different geographical regions of Turkey" were searched among articles published in both English and Turkish language within the time span from 1999 to 2015. Data analysis was performed using MedCalc 12.7.0. Each article was weighted according to the number of isolated H. pylori strains. Pooled proportion analysis was performed.
  
  
  RESULTS
  Twenty-one Turkish studies including 1059 H. pylori strains were included in this review. The overall primary antibiotic resistance rates of H. pylori strains isolated in Turkey were as follows: amoxicillin 3 (0.971%), clarithromycin 425 (24.864%), metronidazole 75 (33.747%), tetracycline 2 (3.511%), and levofloxacin 31 (23.769%).
  
  
  CONCLUSIONS
  Primary antibiotic resistance against H. pylori in Turkey shows differences between geographical regions and population densities. There is an increase in primary resistance rates to clarithromycin and metronidazole in different years. The data are not sufficient for tetracycline, amoxicillin, and levofloxacin. High clarithromycin resistance rates were mostly detected in overpopulated cities like Ankara (north), Izmir (west), Istanbul (west), and Bursa (west).
authors.affiliation: Department of Medical Microbiology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Bekir
authors.initials: B
authors.lastname: Kocazeybek
authors.affiliation: Department of Medical Microbiology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Hrisi Bahar
authors.initials: HB
authors.lastname: Tokman
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D015995:Prevalence; D062211:Spatio-Temporal Analysis; D014421:Turkey / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents
keywords: Helicobacter pylori; Turkey; clarithromycin resistance; metronidazole resistance