title: Evaluation of clarithromycin resistance and cagA and vacA genotyping of Helicobacter pylori strains from the west of Ireland using line probe assays.
abstract: The prevalence of clarithromycin resistance-associated mutations, the cytotoxin-associated gene (cagA), and the various vacuolating cytotoxin (vacA) genotypes was determined in 50 gastric biopsy specimens from Helicobacter pylori-infected patients, using line probe assays. The clarithromycin resistance-associated mutation A2143G was detected in H. pylori strains from 26% of the specimens, which suggested that the high rate of H. pylori treatment failure in Ireland may be partly attributable to the presence of these mutations. All strains examined carried the vacA s1 genotype, and 76% were cagA positive. Of these 50 specimens, 13 (26%) carried H. pylori strains with vacA midregion genotype m1, 29 (58%) carried strains that were m2, 1 (2%) was infected by a strain that was positive for both m1 and m2, and 7 (14%) carried strains that could not be typed.
authors.affiliation: National Diagnostics Centre, BioResearch Ireland, National University of Ireland, Galway, Ireland.
authors.forename: K A
authors.initials: KA
authors.lastname: Ryan
authors.forename: L J
authors.initials: LJ
authors.lastname: van Doorn
authors.forename: A P
authors.initials: AP
authors.lastname: Moran
authors.forename: M
authors.initials: M
authors.lastname: Glennon
authors.forename: T
authors.initials: T
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Maher
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics*; D001706:Biopsy; D017291:Clarithromycin / Q000494:pharmacology*; D015342:DNA Probes; D004269:DNA, Bacterial / Q000032:analysis; D004076:Digoxigenin / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000235:genetics; D020459:Genes, rRNA; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D007494:Ireland; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D013270:Stomach / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015342:DNA Probes; D004269:DNA, Bacterial; D012338:RNA, Ribosomal, 23S; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D017291:Clarithromycin; D004076:Digoxigenin