title: Clarithromycin-resistant genotypes and eradication of Helicobacter pylori.
abstract: OBJECTIVE
  To compare the eradication rates among the different point mutations and the efficacy of triple therapy and a sequential regimen according to genotypic resistance.
  
  
  METHODS
  Post hoc retrospective cohort study in a tertiary referral center for pediatric gastroenterology in southern Italy. All 168 children who were positive for Helicobacter pylori were enrolled. Patients had received clarithromycin-based 7-day triple therapy (73 children) or 10-day sequential therapy regimen (95 children). Real-time polymerase chain reaction for assessing clarithromycin resistance was performed on sections of paraffin-embedded gastric biopsy samples.
  
  
  RESULTS
  H pylori eradication was achieved in 16 of 32 (50%) children with the A2143G mutation, in 8 of 10 patients with either A2142G or A2142C strains (80%), and in 112 of 116 children with susceptible strains (88.9%). The presence of A2143G mutation was associated with a lower cure rate compared with the rate in the absence of this mutation (50% vs. 89%; P = .001). The sequential regimen achieved a higher cure rate than triple therapy in patients with A2143G mutant strains (80% vs nil; P < .001).
  
  
  CONCLUSIONS
  The A2143G mutation confers higher risk of treatment failure. Sequential regimen has higher efficacy than standard therapy, even in children with A2143G mutatant strains.
authors.affiliation: Department of Biomedicina dell'Età Evolutiva, University of Bari, Italy. rfrancavilla@bioetaev.uniba.it
authors.forename: Ruggiero
authors.initials: R
authors.lastname: Francavilla
authors.forename: Elena
authors.initials: E
authors.lastname: Lionetti
authors.forename: Stefania
authors.initials: S
authors.lastname: Castellaneta
authors.forename: Marcella
authors.initials: M
authors.lastname: Margiotta
authors.forename: Domenico
authors.initials: D
authors.lastname: Piscitelli
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Lorenzo
authors.forename: Luciano
authors.initials: L
authors.lastname: Cavallo
authors.forename: Enzo
authors.initials: E
authors.lastname: Ierardi
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000494:pharmacology*; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D005260:Female; D005838:Genotype; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D017291:Clarithromycin