title: Fluorescence in situ hybridization vs. epsilometer test for detection of clarithromycin-susceptible and clarithromycin-resistant Helicobacter pylori strains in gastric biopsies from children.
abstract: OBJECTIVE
  To compare the results of culture and epsilometer test with fluorescence in situ hybridization for the detection of Helicobacter pylori and the presence of clarithromycin-susceptible and clarithromycin-resistant strains in antral biopsies from children.
  
  
  METHODS
  Antral biopsies from 149 unselected children were investigated prospectively; 15 had previously received anti-H. pylori therapy. H. pylori status was defined by histology, rapid urease test and 13C-urea breath test. Fluorescence in situ hybridization was applied on fresh tissue with probes specific for the clarithromycin-susceptible wild type and three clarithromycin-resistant mutants. Susceptibility to clarithromycin was tested by epsilometer test in two laboratories.
  
  
  RESULTS
  Culture and fluorescence in situ hybridization gave negative results in all 66 H. pylori-negative children (specificity, 100%). Of 83 infected children, cultures were successful in 75 (90%), epsilometer test in 71 (86%) and fluorescence in situ hybridization in 77 (93%). Eleven children (13%) showed discrepant results between the applied methods, indicating mixed infection. Clarithromycin-resistant isolates were identified in 16 of 73 previously untreated children.
  
  
  CONCLUSIONS
  Primary resistance to clarithromycin is common (22%) in H. pylori isolates from children living in Germany. Fluorescence in situ hybridization is an excellent, fast method for the detection of H. pylori and clarithromycin-resistant mutants in gastric biopsies. Multiple biopsies identify mixed infections, indicating that clarithromycin-resistant and clarithromycin- susceptible strains are not evenly distributed within the stomach.
authors.affiliation: Dr v Haunerches Kinderspital, Ludwig-Maximilians University, Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Feydt-Schmidt
authors.forename: H
authors.initials: H
authors.lastname: Rüssmann
authors.forename: N
authors.initials: N
authors.lastname: Lehn
authors.forename: A
authors.initials: A
authors.lastname: Fischer
authors.forename: I
authors.initials: I
authors.lastname: Antoni
authors.forename: D
authors.initials: D
authors.lastname: Störk
authors.forename: S
authors.initials: S
authors.lastname: Koletzko
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001706:Biopsy; D001944:Breath Tests / Q000379:methods; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D011446:Prospective Studies; D011706:Pyloric Antrum / Q000382:microbiology; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents; D017291:Clarithromycin