title: Antimicrobial susceptibility of 6 antimicrobial agents in Helicobacter pylori clinical isolates by using EUCAST breakpoints compared with previously used breakpoints.
abstract: BACKGROUND
  The aim of this study was to determine the differences in percentage resistance in H. pylori clinical isolates using EUCAST breakpoints compared with previously used breakpoints. MIC value distribution in H. pylori clinical isolates was also studied.
  
  
  METHODS
  Susceptibility to amoxicillin, tetracycline, metronidazole, clarithromycin, rifampicin and levofloxacin was performed by E-test in 824 H. pylori clinical isolates. EUCAST and previous breakpoints defined resistance as follows: MIC >0.12mg/L and ≥2mg/L for amoxicillin, >8mg/L and ≥8mg/L for metronidazole, >0.5mg/L and ≥1mg/L for clarithromycin, >1mg/L and ≥32mg/L for rifampicin, and >1mg/L and ≥4mg/L for tetracycline and >1mg/L levofloxacin.
  
  
  RESULTS
  Overall resistance rate by EUCAST and by previous breakpoints was 8.5% and 3.2% for amoxicillin, 0.6% and 0.1% for tetracycline, 39.2% and 39.7% for metronidazole, 51.2% and 51.2% for clarithromycin, 32% and 3.1% for rifampicin, and 6.7% and 6.7% for levofloxacin.
  
  
  CONCLUSIONS
  When using the different breakpoints for antimicrobial susceptibility testing, similar results were found with most antibiotics tested (tetracycline, metronidazole, clarithromycin, and levofloxacin), except for amoxicillin and rifampicin.
authors.affiliation: Servicio de Microbiologia, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain; Departamento de Medicina Preventiva, Salud Pública y Microbiologia, Facultad de Medicina, Universidad Autónoma de Madrid, Spain. Electronic address: talarcon@helicobacterspain.com.
authors.forename: Teresa
authors.initials: T
authors.lastname: Alarcón
authors.affiliation: Unidad de Gastroenterología Pediátrica, Hospital Universitario Doce de Octubre, Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Urruzuno
authors.affiliation: Unidad de Gastroenterología Pediátrica, Hospital Universitario Niño Jesus, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain.
authors.forename: Maria Josefa
authors.initials: MJ
authors.lastname: Martínez
authors.affiliation: Servicio de Microbiologia, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Domingo
authors.affiliation: Servicio de Microbiologia, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Llorca
authors.affiliation: Servicio de Microbiologia, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Correa
authors.affiliation: Servicio de Microbiologia, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: López-Brea
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D005260:Female; D005756:Gastritis / Q000382:microbiology*; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000592:standards*; D008875:Middle Aged; D011706:Pyloric Antrum / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents
keywords: Clarithromycin resistance; EUCAST breakpoints; Helicobacter pylori; Multi-resistance; Punto de corte EUCAST; Resistencia a Claritromicina