Genotypic resistance in Helicobacter pylori strains correlates with susceptibility test and treatment outcomes after levofloxacinand clarithromycin-based therapies
Journal
Antimicrobial Agents and Chemotherapy
Journal Volume
55
Journal Issue
3
Pages
1123-1129
Date Issued
2011
Author(s)
Chang C.-Y.
Wang Y.-C.
Hung H.-W.
Chian H.
Chang S.-C.
Lin J.-T.
Abstract
The accuracy of genotypic resistance to levofloxacin (gyrA mutations) and its agreement with treatment outcomes after levofloxacin-based therapy have not been reported. We aimed to assess the correlation. Helicobacter pylori strains isolated from patients who received levofloxacin-based and clarithromycin-based triple therapies in a previous randomized trial were analyzed for point mutations in gyrA and 23S rRNA. PCR followed by direct sequencing was used to assess the gyrA and 23S rRNA mutations. An agar dilution test was used to determine the MICs of clarithromycin and levofloxacin. We found that the agreement between genotypic and phenotypic resistance to levofloxacin was best when the MIC breakpoint was >1 μg/ml (kappa coefficient, 0.754). The eradication rates in patients with and without gyrA mutations were 41.7% and 82.7%, respectively (P = 0.003). The agreement between genotypic and phenotypic resistance to clarithromycin was best when the MIC breakpoint was >2 μg/ml (kappa, 0.694). The eradication rates in patients with and without 23S rRNA mutations were 7.7% and 93.5%, respectively (P 1 μg/ml and >2 μg/ml, respectively.
SDGs
Type
journal article