title: Heterogeneous susceptibility to metronidazole and clarithromycin of Helicobacter pylori isolates from a single biopsy in adults is confirmed in children.
abstract: The aim of this study was to assess the resistance to metronidazole and clarithromycin of individual colonies of Helicobacter pylori from a single biopsy taken from 14 adults and 14 children. The Etest was used to determine the minimum inhibitory concentrations (MICs) of these two antimicrobial drugs for ten individual H. pylori colonies isolated from each initial gastric biopsy culture. We confirmed the heterogeneity in metronidazole and clarithromycin resistance in children as seen in adults before anti-H. pylori treatment. The number of resistant individual colonies ranged from two to nine depending on the subject. All individual colonies from the same biopsy that were resistant to clarithromycin were genetically identical according to randomly amplified polymorphic DNA testing and exhibited the same point mutation according to polymerase chain reaction-restriction fragment length polymorphism.
authors.affiliation: University Paris V, Service Bacteriology, Hôpital Cochin-Saint Vincent de Paul, France. j.raymond@svp.ap-hop-paris.fr
authors.forename: Josette
authors.initials: J
authors.lastname: Raymond
authors.forename: Bang
authors.initials: B
authors.lastname: Nguyen
authors.forename: Michel
authors.initials: M
authors.lastname: Bergeret
authors.forename: Christophe
authors.initials: C
authors.lastname: Dupont
authors.forename: Nicolas
authors.initials: N
authors.lastname: Kalach
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001706:Biopsy; D002648:Child; D017291:Clarithromycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics*; D006801:Humans; D008795:Metronidazole / Q000494:pharmacology*; D008875:Middle Aged; D017354:Point Mutation; D012150:Polymorphism, Restriction Fragment Length; D011446:Prospective Studies; D019105:Random Amplified Polymorphic DNA Technique; D013270:Stomach / Q000382:microbiology* / Q000473:pathology
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D008795:Metronidazole; D017291:Clarithromycin