Evaluation of clarithromycin resistance and cagA and vacA genotyping of Helicobacter pylori strains from the West of Ireland using line probe assays

The prevalence of clarithromycin resistance-associated mutations, the cytot oxin-associated gene (cagA), and the various vacuolating cytotoxin (vacA) g enotypes was determined in 50 gastric biopsy specimens from Helicobacter py lori-infected patients, using line probe assays, The clarithromycin resista nce-associated mutation A2143G was detected in H. pylori strains from 26% o f the specimens, which suggested that the high I ate of H, pylori treatment failure in Ireland may be partly attributable to the presence of these mut ations,;UI strains examined carried the vacA s1 genotype. and 76% were cagA positive, Of these 50 specimens, 13 (26%) carried H. pylori strains with v acA midregion genotype mi, 29 (58%) carried strains that were m2, 1 (2%) wa s infected by a strain that was positive for both mi and m2, and 7 (14%) ca rried strains that could not be typed.