title: Helicobacter pylori Clarithromycin Resistance and Treatment Failure Are Common in the USA.
abstract: Helicobacter pylori antibiotic resistance leads to frequent treatment failure. However, the current US prevalence of H. pylori clarithromycin resistance and treatment failure is unknown.
  
  
  
  To determine the prevalence of clarithromycin-resistant H. pylori and its impact on treatment failure in the USA.
  
  
  
  A multicenter, retrospective, cohort study for clarithromycin-resistant H. pylori was conducted over four academic medical centers in different geographic regions of the USA. Gastric biopsy material, residual from standard clinical pathologic examination, was examined for clarithromycin resistance by DNA sequencing of H. pylori 23S rRNA.
  
  
  
  One hundred and twenty-four cases of H. pylori gastritis were examined from medical centers in four different geographic regions of the USA. The overall prevalence of clarithromycin resistance was 32.3 % (range 23.1-45.8 %). There was no significant difference in the prevalence of clarithromycin resistance by study site, gender, age, or race/ethnicity. In a subset of 67 patients that had clinical follow-up data, the overall prevalence of clarithromycin resistance was 31.3 %. There was a 2.9-fold increase (p = 0.002) in treatment failure for cases with clarithromycin resistance (57.1 %) compared to wildtype H. pylori (19.6 %).
  
  
  
  H. pylori clarithromycin resistance in the USA exceeds the estimated 20 % prevalence compatible with successful empiric antibiotic therapy. This resistance resulted in a significant rate of treatment failure in all sites surveyed. Empiric therapy in the USA should be used with caution until there is better regional or local determination of H. pylori antibiotic resistance.
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA. jason.park@childrens.com.|Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA. jason.park@childrens.com.|Department of Pathology, Children's Health Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA. jason.park@childrens.com.
authors.forename: Jason Y
authors.initials: JY
authors.lastname: Park
authors.affiliation: Medical Service, Dallas Veterans Affairs Medical Center, Dallas, TX, USA.|Division of Gastroenterology and Hepatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Kerry B
authors.initials: KB
authors.lastname: Dunbar
authors.affiliation: Department of Pathology, Children's Health Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA.
authors.forename: Midori
authors.initials: M
authors.lastname: Mitui
authors.affiliation: Department of Pathology, Ohio State University Wexner Medical Center, Columbus, OH, USA.
authors.forename: Christina A
authors.initials: CA
authors.lastname: Arnold
authors.affiliation: Department of Pathology and Lab Medicine, Mayo Clinic, Arizona, Scottsdale, AZ, USA.
authors.forename: Dora M
authors.initials: DM
authors.lastname: Lam-Himlin
authors.affiliation: Division of Anatomic Pathology, Department of Pathology, University of California, San Diego, San Diego, CA, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Valasek
authors.affiliation: Division of Anatomic Pathology, Department of Pathology, University of California, San Diego, San Diego, CA, USA.
authors.forename: Irene
authors.initials: I
authors.lastname: Thung
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Chinemerem
authors.initials: C
authors.lastname: Okwara
authors.affiliation: Division of Gastroenterology and Hepatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Texas Digestive Disease Consultants, Dallas, TX, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Coss
authors.affiliation: Medical Service, Dallas Veterans Affairs Medical Center, Dallas, TX, USA.|Division of Gastroenterology and Hepatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.|Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Byron
authors.initials: B
authors.lastname: Cryer
authors.affiliation: Department of Pathology, Virginia Commonwealth University Health System, Richmond, VA, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Doern
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000658:Amoxicillin / Q000627:therapeutic use; D000863:Antacids / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001729:Bismuth / Q000627:therapeutic use; D017291:Clarithromycin / Q000627:therapeutic use*; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004359:Drug Therapy, Combination; D005260:Female; D005753:Gastric Mucosa; D005756:Gastritis / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D008875:Middle Aged; D015995:Prevalence; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D012189:Retrospective Studies; D017211:Treatment Failure; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000863:Antacids; D000900:Anti-Bacterial Agents; D054328:Proton Pump Inhibitors; D012338:RNA, Ribosomal, 23S; D008795:Metronidazole; D000658:Amoxicillin; D017291:Clarithromycin; D001729:Bismuth
keywords: 23S rRNA; Antibiotic resistance; Clarithromycin; Helicobacter pylori; Treatment failure