title: Primary resistance to clarithromycin in clinical strains of Helicobacter pylori isolated from children in Poland.
abstract: Helicobacter pylori resistance to clarithromycin is an important factor in the failure of eradication therapy. The resistance results from point mutations in the 23S rRNA gene of H. pylori. The prevalence of primary resistance of H. pylori to clarithromycin in children and mutations associated with resistance were studied and it was found that 23.5% (23/98) of H. pylori strains isolated in our hospital during 1998-2000 were resistant to clarithromycin. The primary resistance was mainly caused by an A2143G mutation, but the isolates with an A2142G mutation had higher MICs for clarithromycin compared with those with an A2143G mutation: median MIC 256 versus 16 mg/l. Comparison of our data with previous results showed that the prevalence of H. pylori resistance to clarithromycin in children has increased in Poland over the last three years, however the difference was not significant (23.5 vs. 17%, P=0.22).
authors.affiliation: Department of Clinical Immunology, Children's Memorial Health Institute, Aleja Dzieci Polskich 20, 04-736 Warsaw, Poland. fangrat@supermedia.pl
authors.forename: K
authors.initials: K
authors.lastname: Dzierzanowska-Fangrat
authors.forename: E
authors.initials: E
authors.lastname: Rozynek
authors.forename: P
authors.initials: P
authors.lastname: Józwiak
authors.forename: D
authors.initials: D
authors.lastname: Celińska-Cedro
authors.forename: K
authors.initials: K
authors.lastname: Madaliński
authors.forename: D
authors.initials: D
authors.lastname: Dzierzanowska
mesh_terms: D000293:Adolescent; D002648:Child; D017291:Clarithromycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D017354:Point Mutation / Q000235:genetics; D011044:Poland; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics
chemical_list: D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D017291:Clarithromycin