title: In vitro exposure to macrolide antibiotics in Helicobacter pylori strains isolated from children.
abstract: Clarithromycin resistance of Helicobacter pylori is a serious problem in eradication therapy. We investigated whether the use of maclorides (clarithromycin, erythromycin, and azithromycin) induces clarithromycin resistance in the organism. Twenty H. pylori strains were isolated from pediatric patients with gastrointestinal symptoms. The minimum inhibitory concentrations (MICs) of each macrolide antibiotic were determined by the Etest. Among these, 17 strains susceptible to macrolide antibiotics were used for the in vitro induction of drug resistance. In each of these 17 strains of H. pylori, 30-day exposure to clarithromycin in experiments for in vitro induction did not change the MIC of any antibiotic, nor did it induce either the A2143G or the A2144G mutation in the 23S rRNA gene. These results suggest that the use of macrolide antibiotics does not induce clarithromycin resistance in H. pylori by 23S rRNA gene mutation.
authors.affiliation: Department of Microbiology, Miyagi University, 1 Gakuen, Taiwa-cho, Miyagi 981-3298, Japan. hujimara@myu.ac.jp
authors.forename: Shigeru
authors.initials: S
authors.lastname: Fujimura
authors.forename: Seiichi
authors.initials: S
authors.lastname: Kato
authors.forename: Kazuie
authors.initials: K
authors.lastname: Iinuma
authors.forename: Akira
authors.initials: A
authors.lastname: Watanabe
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005767:Gastrointestinal Diseases / Q000382:microbiology*; D020459:Genes, rRNA; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009154:Mutation; D012338:RNA, Ribosomal, 23S / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D012338:RNA, Ribosomal, 23S; D017291:Clarithromycin